Ph.d.-afhandling: Johan Mottelson - Out of Control by Det Kongelige Akademi - Arkitektur, Design, Konservering

PhD Thesis

OUT OF CONTROL

On Urban Morphology of Informal Settlements in East Africa Johan Mottelson

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It is strange that those with the least money inhabit the most expensive commodity – earth; those who pay, what is free – air. - Rem Koolhaas

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Out of Control: On Urban Morphology of Informal Settlements in East Africa PhD Thesis Copyleft: All wrongs reserved All photos, drawings, and text by Johan Mottelson, unless noted Published by The Royal Danish Academy - Architecture, Design, Conservation This research was funded by The Danish Council for Independent Research (ID: 7023-00007B) Published in 2021 ISBN: 978-87-7830-839-9 Contact: www.mottelson.com / jmot@kglakademi.dk

Formal city skyline seen from Maxaquene A, Maputo, Mozambique →

ACKNOWLEDGMENTS

This PhD thesis benefited from the support, stimulating conversations, and interesting perspectives of numerous individuals who deserve recognition for their valuable contributions. I would like to thank my supervisors Jørgen Eskemose and Deane Simpson for their relentless support throughout my doctoral studies. I would like to thank Remígio Chilaule, Alessandro Venerandi, and Paul Jenkins for their respective contributions to the work presented in this thesis along with their critical perspectives unfolded in numerous appreciated discussions. I would like to thank my father Jan Clausen for teaching me how to draw and my mother Martha Mottelson for teaching me how to think – two essential tools for an architect and researcher. I would like to thank Sophie Inanloo and Hannah Inanloo Mottelson for the love and care that enable me to do what I do. I would like to thank Andreas Hagedorn Krogh, Morten Birk Jørgensen, and Aske Mottelson for challenging my views on research and their enlightening company. I would like to thank Maria Reimer Jensen, Amanda Mottelson, and Mia Mottelson for their ongoing support of my work. I would like to thank my extended family in Maxaquene. Namely, Raul Carlos Machaieie, Salomão Gabriel Machava, Mario Machaieie, Nelson Eugenio, Joaquim Cuna, André Nungo Cuna (RIP), Manel Machava, Pilote Mavale, Tia Masupa, Marietta Machaieie, Celso Machaieie, Dercio Cirillo, Valdemiro Dinhova, Bruno Mauro Chirindza, Lucas Lavo, Manito Ayoob, and Miguel Tanga for helping me integrate in their community and thereby allowing me to acquire much of the understanding of informal settlements

in East Africa presented in this thesis. I would like to thank my colleagues at the Royal Danish Academy and the Institute of Architecture, Urbanism and Landscape for creating an inspiring and stimulating environment at the academy for the exploration of new research topics. This includes Katrine Lotz, Morten Meldgaard, Knud Kappel, Jonna Majlgaard Krarup, Jakob Knudsen, Gustavo Ribeiro, and Anders Hermund. I would like to thank the local authorities in the settlements studied in this thesis for permitting the spatial surveys as well as the members of the communities of each settlement who participated in the field interviews. I would like to thank the following residents who facilitated the fieldwork: Bambu, Mario Mugano Xikumbane, Ali Muhammed Muhina, Ally Hassan Ally, Daniel Futwax, John Saturday Bwambale, David Esenga, Kyeyune Daniel, Vero Razafinirina, Ravaonirina Andrine, Rasoanirina Zoeline, and Rabevaza Selestin. I would like to thank Jakob Kisker, Morten Risom, Morten Fauerby Thomsen, Jonas Engberg, Lene Lange, Christopher Tusiime, Mary Awori, Japiel Ndayahoze, Meva Rakotoson, Mitantsoa Rakotoanosy, WSUP Madagascar, Care Uganda, Care Denmark, Anna Wahlén, Margarida Waco, Anton Ryslinge, Architects without Borders – Denmark, Pedro Bulande, Alexandre Camilo, and Estamos for their contributions to the practice-based projects presented in this thesis. Finally, I would like to thank Marco Prahm, Pedro Vilanculos, Anna Stærmose, Lagiya Khatib, Martina Bo Rubino, and Maria Joana Sinde for their individual contributions to my early work. Bedroom of low-income household in Maxaquene A, Maputo, Mozambique →

Table of contents Abstract Preface

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PART I: BACKGROUND Introduction

Context Informal settlements in East Africa Historical context Current demographic developments

State of the art Location, Urban Density, and Property Prices Urban Morphology of Informal Settlements

Overview of research papers

References

PART II: RESEARCH PAPERS

A New Hypothesis on Informal Land Supply, Livelihood, and Urban Form in Sub-Saharan African Cities By Johan Mottelson

On the Impact of Urban Planning of Informal Settlements in Sub-Saharan Africa By Johan Mottelson

Urban Densification of Informal Settlements in Sub-Saharan Africa: An Analysis of Recent Developments in Maputo, Mozambique By Johan Mottelson

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A Fine-Grain Multi-Indicator Analysis of the Urban Form of Five Informal Settlements in East Africa By Johan Mottelson & Alessandro Venerandi

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Urban Form of Informal Settlements in East Africa: A Taxonomy of Block Types By Alessandro Venerandi & Johan Mottelson

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Understanding Density in Unplanned and Unregulated Settlements of Peri-urban Africa: A Case Study of Maputo, Mozambique By Paul Jenkins & Johan Mottelson

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PART III: PRACTICE-BASED PROJECTS Spatial planning in Kyangwali By Johan Mottelson and CARE Uganda

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Tana Toilet Blocks By Johan Mottelson and WSUP Madagascar

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Maxaquene Txombene By Johan Mottelson, Remígio Chilaule, Jakob Kisker, and Celso Machaieie

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Land rights in Maputo By Johan Mottelson, Jørgen Eskemose, Pedro Bulande, and Estamos

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Informal Horizons By Johan Mottelson, Anton Ryslinge, Anna Wahlén, and Margarida Waco

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Interpositions By Johan Mottelson

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Casas Melhoradas By Johan Mottelson, Jørgen Eskemose, and Raul Machaieie

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Born and Raised in the Ghetto By Johan Mottelson

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Mafalala Futures By Johan Mottelson and Remígio Chilaule

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PART IV: CONCLUSION Theoretical contributions

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Policy recommendations

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Reflection on practice

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Future horizons

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Pitfalls and potentials

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References

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ABSTRACT

Most of the ongoing extensive urbanization in East Africa is informal and occurs beyond the limits of state control and regulatory systems. The urban majority in the region resides in informal settlements characterized by limited urban planning, construction without formal permits, and lack of formal land titles. Issues with substandard housing, overcrowding, insecure tenure as well as inadequate access to water and sanitation are widespread in these areas and compromise the livelihood of tens of millions of urban dwellers. Few studies have investigated the urban form of informal settlements even though spatial factors and urban form indicators such as inadequate access conditions, inefficient use of space, high level of building coverage, and limited public space are linked to some of the urban deficiencies in informal settlements. This PhD thesis presents analyses of the urban form of informal settlements in East Africa, based on urban morphology and location theory in order to enhance the knowledge on contemporary urban development in the region and thereby improve the basis for increasing the efficacy of urban planning and policy in addressing the wide-ranging issues linked to the proliferation of informal settlements. The thesis includes a number of practicebased design, architecture, and spatial planning projects that were produced in parallel with the research. These projects highlight central issues in relation to informal urban development in East Africa such as urban densification, access to sanitation, and innovation in spatial planning and land use management. The thesis is article-based and includes a number of research papers focusing on various subjects related to the urban form of informal settlements in East Africa. The paper A New Hypothesis on Informal Land Supply, Livelihood, and Urban Form in Sub-Saharan African Cities presents an analysis of informal urban land use in four major cities in East Africa, as well as an analysis of urban form and household conditions in a case study area in each city. The study found more compact urban form, higher proportion of tenants and overcrowding, and lower proportion of household access to water and sanitation in the examined cities with limited informal urban land use. The study argues that government repression of informal urban development decreases informal land supply and leads to increased competition in the informal land market, causing higher costs of accommodation and consequent fewer household resources for investments in infrastructure and thereby more compromised livelihood. The paper On the Impact of Urban Planning of Informal Settlements in Sub-Saharan Africa compares the urban form of three centrally located unplanned informal settlements with three adjacent planned informal settlements in Maputo, Mozambique in order to assess the long-term impact of urban planning on the urban form of informal settlements. The study found higher built densities, higher public space

ratios, and higher average street widths in the planned areas compared to the unplanned areas. Accordingly, the study suggests that urban planning has a significant long-term impact on the urban form of informal settlements despite the lack of state control of the urban development. The paper Urban Densification of Informal Settlements in Sub-Saharan Africa: An Analysis of Recent Developments in Maputo, Mozambique and the book chapter Understanding density in unplanned and unregulated settlements of periurban Africa: a case study of Maputo, Mozambique examine built densification of three unplanned informal settlements and developments of population densities in Maputo, Mozambique. The studies found increasing built densities in all three case study areas and decreasing population densities in two case study areas. The studies thus suggest that the urban population growth in Maputo is mainly accommodated through urban expansion. The papers A Fine-Grain Multi-Indicator Analysis of the Urban Form of Five Informal Settlements in East Africa and A Taxonomy of Informality: Exploring Block Types in Five informal Settlements in East Africa use statistical analysis of the urban form of informal settlements at high resolution. The first presents statistical comparison of indicators of urban form in order to explore similarities and differences of the analyzed settlements. The latter presents a clustering analysis of different block types. The papers highlight distinctive urban form features of the analyzed neighborhoods and thus provide new insights on the spatial conditions of informal settlements in the region. Mainstream urban economic theory emphasizes the importance of transportation systems in relation to the development of urban form. This thesis adds new nuances to these theories by documenting that government attitudes towards informal urban development in cities where the majority is financially excluded from the formal housing market are critical for understanding the urban morphology of informal settlements. Finally, the thesis argues that Western planning paradigms are not appropriate in the context of much of East Africa as local authorities lack the resources to administer the urban development according to the regulation and much of the population lack the resources to comply with regulation. On this basis, the thesis discusses alternative approaches to urban planning that require fewer resources to administer and support production of affordable legal housing. The thesis presents a number of policy recommendations informed by the research papers, such as new forms of land titling, innovation in land use management, increasing mandate for decision-making to local administrations, road pricing, and implementation of robust street grids in peripheral areas before the urban fabric consolidates. The thesis argues that such policy measures may address some of the issues emblematic to informal urban development in the region and thereby enhance the future sustainable development of major cities in East Africa. Lack of waste management in Kibera, Nairobi, Kenya →

PREFACE

Ten years ago, I incidentally ended up as an exchange student at Faculdade de Arquitectura e Planeamento Físico, Universidade Eduardo Mondlane in Maputo, Mozambique. I quickly realized that urban development in sub-Saharan Africa is among the most interesting and important topics for contemporary architects and urban planners. The scale and scope of the issues confronting African cities are simply colossal and closely tied to the greater challenges facing humanity, such as sustainable development, climate change, migration, and inequality. In preparation for my studies in Maputo, I examined the city on Google Maps and was instantly intrigued by the morphological differences between the formal and informal parts of the city. I wanted to go to Mafalala; the most centrally located and most dense informal settlement in the city situated adjacent to an old Portuguese bull-fighting arena from the colonial period. When I arrived in Maputo, I barely knew a word of Portuguese and was advised not to go to Mafalala alone. The neighborhood was notorious and the English-speaking privileged segments of society I was around in the city center had hardly visited the informal settlements at all. Time passed and I eventually became friends with Pedro Vilanculos, a sociology student who did various types of fieldwork in the informal settlements. He took me on a tour in Mafalala and I began exploring the informal settlements around the city on my own. I knocked on doors, explained in broken Portuguese that I was a Danish architecture student, and asked if I could see the house. I became fascinated with the informal settlements and I began asking some of the questions fundamental to the work presented in this thesis. What factors influence the development of the urban form of informal settlements? What explains the distribution of urban densities in the city? Why are the informal settlements in Maputo characterized by relatively low urban densities compared to informal settlements in other parts of the world? And how can architects support improvement of the living conditions in informal settlements? During this process, I began developing ideas for a low-cost housing project. I worked with Remígio Chilaule, a fellow student at the faculty of architecture in Maputo, and later I got in touch with Jørgen Eskemose, a senior researcher at the Royal Danish Academy who spent most of his adult

life working in the context of sub-Saharan Africa. Jørgen subsequently became my closest colleague and longtime collaborator at the academy and Remígio got a position at the faculty of architecture in Maputo and became a peer, close friend, and collaborator on numerous projects. After returning to Denmark, I started applying for funds to realize my dream of building a low-cost housing prototype in the informal settlements of Maputo along with a small group of volunteers from Architects without Borders – Denmark. I was a young and naïve student, but we succeeded in acquiring some minor funding. I skipped the official graduation ceremony just days after my thesis presentation in order go to Maputo and initiate the construction of the first phase of the affordable housing project, Casas Melhoradas. Jørgen put me in touch with Estamos, a local NGO, and Raul Machaieie, a local carpenter who got engaged in the work. Both became long time collaborators. Later, I moved in with Raul’s family in Maxaquene, a centrally located informal settlement in the city. Today, I consider the neighborhood my second home. As urban development in sub-Saharan Africa is somehow in the periphery of the core topics in research and education at the academy, my continued loose affiliation with the school was conditioned by my capability in acquiring external funding. Consequently, I began developing projects focusing on various aspects related to informal settlements after returning home. During my studies, I had mostly done charcoal sketches and built cardboard models while listening to hip-hop. Accordingly, I had limited experience with funding applications, academia, and writing in general. However, some of the applications succeeded and a variety of partnerships developed thereafter. I did multiple exhibition projects, new housing prototypes, and I organized fieldwork with students in Maputo. This enabled extensive traveling to major cities across the continent and long stays in Maxaquene several times a year. In parallel with my slow integration into the community in Maxaquene along with the fieldwork in other parts of the region, I slowly became acquainted with the academic literature on informal settlements. I drafted a PhD proposal on the airplane while traveling from Lagos to Nairobi and eventually, the Danish Council for Independent Research decided to fund the project. It has been great a privilege to spend three years studying the most interesting topic I can imagine and I cannot express my gratitude for the opportunity I was given. Construction site in Maputo, Mozambique, photo by Martina Bo Rubino →

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PART I: BACKGROUND INTRODUCTION

East Africa is one of the least urbanized parts of the world. However, the region is characterized by rapid urban population growth due to rural to urban migration and high population growth rates. This leads to comprehensive transformations of the built environment as new houses are constructed in a vast scale to accommodate the extensive urban population growth (UN-Habitat, 2020a). Much of the urban development occurs beyond the limits of state regulatory frameworks due to poor urban majorities and limited state capacity to administer the extensive urban growth. This leads to the proliferation of informal settlements, typified by a lack of state control (UN-Habitat, 2013). The urban majority resides in informal settlements in East Africa and the informal urban development will likely continue to accommodate much of the urban growth in the coming decades (UN-Habitat, 2010). The lack of enforcement of urban regulation in informal settlements leads to increasing problems with infrastructure and service provision, risk of fire and spread of diseases, lack of open spaces, inefficient use of space, and undesirable living conditions (Ruhiiga, 2013). However, the built environment of informal settlements along with the mechanisms that determine its development remain understudied which compromises the basis for the development of effective urban planning and policy to address the issues associated with informal urban development (Visagie & Turok, 2020). Knowledge about the size and spatial distribution of the human population in relation to the built environment is essential for understanding social, economic, and environmental issues and is thus important for developing efficient urban planning and policy (Lowry & Lowry, 2014). Recent studies have documented a correlation between urban form indicators and public health conditions, crime rates, and livability of urban areas (Frank et al., 2005; Kim & Hipp, 2019; A. Venerandi, 2017). Accordingly, urban form metrics are important for conditioning human behavior and livelihood. Many of the issues confronting informal urban development are linked to spatial factors such as inadequate access conditions, inefficient use of space, high level of building coverage, and limited public space (Mottelson & Venerandi, 2020). However, the urban form of informal settlements remains understudied and the consequent limited knowledge of the formation and development of informal settlements limits the capacity to develop effective policy and urban planning in sub-Saharan Africa (UN-Habitat, 2010). This PhD thesis presents empirical studies of the urban morphology of informal settlements in East Africa in order to enhance the knowledge on informal urban development and thereby improve the basis for the development of effective urban planning and policy-making. The thesis is titled Out of Control as lack of state control is the defining characteristic of informal settlements. The thesis is article-based and includes four parts. Part I: Background consists of an introduction,

a context description, a state of the art on urban form of informal settlements, and an overview of the research presented in this thesis supplemented with photos taken in informal settlements during fieldwork. Part II: Research Papers consists of six original research manuscripts that have been published in international peer-reviewed scientific journals, a peer-reviewed book, and conference proceedings. One of the papers is in review for an international scientific journal and is thus pending publication. The papers are presented in the original layout and format of the respective publications. Three of the papers were collaborative projects and the co-authors are specified accordingly. As the papers were published as self-contained manuscripts and as the introduction and conclusion of this thesis address the same fields of research some repetition of content matter occurs in Part I, II, and IV. Part III: Practice-based Projects consists of a number of design, architecture, and urban planning projects which were developed in parallel with the research. These projects do not represent scientific research as they rely on more traditional architecture practice-based methodologies with less rigorous forms of inquiry and experimentation. Accordingly, the practice-based projects are not presented in the format of academic work. As the thesis summarizes previously published research and practicebased work, Part I, III, and IV contain some reproduction of texts previously published (Mottelson, 2019a, 2019b, 2020a, 2021; Mottelson & Andersen, 2018; Mottelson & Chilaule, 2018). Finally, Part IV: Conclusion consists of an overview of the wider theoretical implications of the findings of the research papers, an overview of the policy recommendations presented in the research papers, and a reflection on the future horizons on the study of urban form of informal settlements in sub-Saharan Africa. A number of ‘intermissions’ are interpolated between the different sections and provide subjective atmospheric descriptions of distinct urban conditions observed during the fieldwork.

CONTEXT

This section discusses the key features of informal settlements in East Africa which are essential for understanding the context of the research. Secondly, it provides an overview of the historical development of East Africa which is essential for understanding the contemporary states and systems of governance along with the cultural and political differences across the region. Finally, it provides an overview of recent demographic developments in the region which is essential for understanding the current urbanization trends. Informal settlements in East Africa The terms ‘informal settlements’ and ‘slums’ are often used interchangeably, although the two terms have different definitions. The term ‘slums’ has origins in the 19th-century industrialization in Europe and consequent rapid unsanitary dense urban development characterized by overcrowding, spread of diseases, and increased risk of fires (UN-Habitat, 2003). However, UN-Habitat redefined the term in 2003 referring to a slum household as characterized by one Lack of household access to water in Kibera, Nairobi, Kenya →

or more of the following five factors: insecure tenure, inadequate access to safe water, inadequate access to sanitation, overcrowding, and substandard housing (UNHabitat, 2003). Households with overcrowding are defined by more than two persons per room. Insecure tenure indicates contested right to the land and consequent risk eviction for the occupants. However, the attributes of tenure security are context-dependent. UN-Habitat started using the term ‘slums’ in order to promote government interventions with the aim of improving the living conditions in deprived urban areas in developing countries. However, the use of the term is contested as opponents of the usage argue that it legitimizes eviction of the residents and it is thus used to relocate population, serving economic and political elitist interests (Jenkins, 2013). Some scholars attribute the social stigma associated with the slum term as a reason not to use it. Other scholars argue that low-income neighborhoods will be associated with some forms of stigma irrespective of terminology. Although the validity of such claims remains a subject of discussion, the academic literature on urban development in sub-Saharan Africa largely refers to informal settlements rather than slums (Huchzermeyer, 2014). The OECD defines informal settlements as either A) areas where groups of housing units have been constructed on land that the occupants have no legal claim to, or occupy illegally; or B) unplanned settlements and areas where housing is not in compliance with current planning and building regulations (unauthorized housing) (OECD, 2008). Informal settlements are thus characterized by lack of enforcement of regulation in terms of construction and landownership. The concept of informality was introduced in the 1970s and has origins in economics (Hart, 1973). The ‘informal sector’ refers to the part of the economy which is not governed by the public authorities and is thus not subject to taxation, monitoring, and regulation by the state. Similarly, informal settlements are urban areas that are not governed according to state regulation and thus develop beyond state regulatory boundaries (Jenkins, 2006). While the term ‘slums’ covers both indicators of legality and livelihood, the term ‘informal settlements’ relates to the lack of state control of the urban areas and consequent contested legality. Tenure insecurity is the common denominator of the two terms, although residents of both slums and informal settlements may have secure tenure. However, informal settlements are typically occupied by low-income or poor residents and will often have additional forms of deprivation aside from insecure tenure (including overcrowding, lowquality housing, lack of clean water, and lack of sanitation) (UN-Habitat, 2010). While most of the urban areas described in this thesis are slums according to the UN definition, the term ‘informal settlements’ is used throughout according to the definition of the OECD described above. The proliferation of informal settlements in sub-Saharan Africa is in part a result of lack of resources in the public sectors to administer the comprehensive urban development and in part a result of lack of resources at household level to comply with the regulatory standards. The lack of public capacity to administer the urban growth in sub-Saharan

Africa has led to a widespread lack of land titles along with lack of developed, approved, and implemented urban plans (Owusu, 2013). As construction permits require land titles and approved urban plans, legal construction is thus unattainable for residents of such areas. Provision of drawings and paperwork for formal construction permits requires specialized professionals and thus increases costs of construction. Requirements of the building code, such as minimum structural dimensions, floor to ceiling height, and access conditions, increase costs of construction. Complying with urban regulation thus increases costs and without statesubsidized alternatives, formal housing is unattainable for the urban majorities due to lack of financial resources (Visagie & Turok, 2020). The urban majorities in sub-Saharan Africa are thus financially excluded from the formal legal housing market, reflecting a failure of the formal housing markets to provide affordable accommodation (Angel et al., 2016). Consequently, the lower levels of public administration have developed informal systems of provision of construction permits without formal basis in the law as well as acceptance of construction not complying with the building code, thus lowering the costs of construction and providing more affordable accommodation for the urban poor (Jenkins, 2013). Informal settlements are thus legal grey-zones in which the local public administrations engage in extra-legal practices. Informal settlements typically develop without effective urban planning and enforcement of building code. This development often involves encroachment on the public space, whereby plot limits are expanded, leaving narrow alleys for access, which complicates future infrastructure upgrades and regularization of the neighborhoods (Dovey et al., 2020). Publicly funded infrastructure and provision of services are typically inadequate in informal settlements in East Africa (UN-Habitat, 2016). This is in part due to the contested legality of informal settlements and consequent disclaim of responsibility of the public authorities and in part a result of limited public funding for such investments. Accordingly, provision of infrastructure in informal settlements largely depends on private household investments. Informal settlements in East Africa generally lack sewage (i.e., systems for managing wastewater) and sewerage (i.e., systems for managing rainwater) (Banerjee et al., 2008). In some cases, this leads to unsanitary urban environments compromising public health conditions (Butala et al., 2010). Accordingly, unregulated urban growth and lack of application of the building code can lead to undesirable living conditions, increase the risk of spread of diseases, and exacerbate exposure to unsafe construction. Furthermore, issues with mobility systems (provision of roads and public transport) are common particularly in peripheral areas which have far-reaching negative implications for mobility and economic development (Andreasen & Møller-Jensen, 2017). However, access to information and communication technology, water, and electricity are widespread in informal settlements in sub-Saharan Africa. Provision of these infrastructures has largely proliferated based on market Graffiti in response to gentrification in Katanga, Kampala, Uganda →

Urban farming In the dense urban fabric of Katanga a strange multi-story makeshift structure towers over the settlement. The distinctive building typology stands out as the design responds to the unique programmatic hybrid between poultry farming and charcoal wholesale. The old lady pendulates between interacting with customers buying charcoal for cooking and feeding the chickens roaming the hatchery floors layered on top of another. Urban farming often seems like a hipsteresque leisure activity. In this case, the regulatory vacuum of the informal settlement has enabled economically viable agricultural production in the middle of the city.

mechanisms rather than public investments (Mapunda et al., 2018; O’Keefe et al., 2015; Tsinda et al., 2015). Similarly, technological advancement in production has resulted in reduced costs of industrialized construction materials. The consequent increased accessibility of modern construction materials has led to improved quality of housing across the continent largely based on individual household investments (Tusting et al., 2019). Land holders without formal land titles risk losing their properties as authorities may adopt policies of evicting informal settlements due to the extra-legal conditions of construction without permits and lack of formal landownership (Talukdar, 2018). Accordingly, in such cases, tenants pay a price-premium due to the increased risk of lost investments for the landlords. In other cases, governments grant some property rights protecting the residents of informal settlements along with a de facto acceptance of the extra-legal practice to a greater extent (Jenkins, 2001). ‘Land titling’ refers to the process of delivering rights to occupants of land or property. Land titling thus eradicates tenure insecurity of informal settlements, by formalizing the informal landownership and giving the residents legal rights to the land they occupy (Payne et al., 2009). Some governments recognize that the conditions of the urban development since independence entailed limited options for much of the population to acquire land and housing within the formal system. Accordingly, legal frameworks for formalizing the informal land ownership have been developed through various procedures (Schmidt & Zakayo, 2018). This typically involves some documentation showing the landowner has resided on the given plot over a minimum period, a physical survey of the plot along with a number of application documents. Furthermore, formalization of land ownership will typically require an approved urban plan as well as compliance with the urban plan (Kironde, 2000). However, there are a number of structural conditions constraining the formalization of land ownership. The lack of resources in the public sectors constrains the capacity to process the paperwork of large-scale land titling programs in sub-Saharan Africa (Agyemang & Morrison, 2018). Furthermore, the lack of resources in the public administrations results in a widespread lack of approved urban plans for informal settlements (Deininger et al., 2014). In addition, settlements with approved urban plans may require costly structural adjustments to comply with the plans and the resources for the implementation are not available. Accordingly, land titles are unattainable in such areas. Finally, lack of resources at household levels and disinterest in obtaining formal land titles further curb widespread land titling (Payne et al., 2009). Accordingly, a multitude of structural barriers prevents large-scale implementation of land titling programs.

International organizations such as the UN-Habitat and the World Bank have promoted land titling programs in order to improve the access to public services, enable taxation of properties, raise public revenue, and provide credit for investments. Such initiatives may be linked to global liberalization processes, whereby the importance of the rule of law is emphasized to support free-market mechanisms. Some scholars argue that land titling programs may stimulate economic growth, improve living conditions, and reduce poverty (De Soto, 2001). However, empirical studies suggest that land titling programs have limited impact aside from providing tenure security (Andreasen et al., 2020; Payne et al., 2009). Other scholars argue that residents of informal settlements generally lack access to financial services since informally owned property cannot be used as security for obtaining loans from financial institutions. Informal land ownership thus constrains the residents of informal settlements from using their properties as resources for investments (De Soto, 2002). Lack of formal landownership thus contributes to exclusion from financial services. However, other scholars stress that land titles do not provide access to financial services to low-income groups as banks will not provide loans to citizens without formal work contracts (i.e., workers in the informal economy) whether or not they own property (Bromley, 2009). Some studies suggest that some residents of informal settlements fear eviction and are thus less likely to invest in home improvements and small-scale businesses. This leads to worsened living conditions due to substandard housing and may constrain economic development (van Gelder & Luciano, 2015). Other studies suggest that residents of informal settlements invest in making their homes more permanent as a strategy to achieve tenure security as authorities may consider demolishing permanent homes less legitimate (Bassett, 2007). Other studies suggest that residents of informal settlements do not consider land titles adequate protection from evictions (Payne et al., 2009). These contradicting tendencies likely reflect the different practices concerning evictions across different regions, as some authorities carry out forced evictions frequently, and other authorities de facto accept informal urban development (Mottelson, 2020a). Formalization of land ownership increases the land market value as the formal property rights provide protection from eviction. The increased land market values may consequently lead to increased costs of rental housing in areas undergoing land titling. Poor tenants thus risk exclusion from the housing market due to the rising prices (Angel et al., 2006). Accordingly, land titling does not solitarily suffice in addressing the urban deficiencies in informal settlements and may in fact have negative implications.

Small-scale private outdoor space in Antohomadinika, Antanananarivo, Madagascar → 28

Although informal settlements are defined by a lack of state control of the urban development, the reality is more complex than the informal-formal binary distinction. In most informal settlements, local public authorities are appointed, such as chiefs, block leaders, and ten-cell leaders (Ribot, 2002; Smit, 2018). These are responsible for resolving local issues and typically govern with some extra-legal practice. In many cases, there are no approved urban plans for the settlements, and the residents are therefore unable to apply for formal construction permits. Nevertheless, informal permits are issued by the local administration, without a legal basis and with no involvement of the higher levels of municipal administration. The local neighborhood administrations thus carry out some form of governance of the development of the neighborhoods despite the lack of formal mandate to do. However, as such practices are not established on the basis of the law, it is plausible that these practices differ between neighborhoods (Mottelson, 2021). While such informal systems operate through extra-legal procedures, it is evident that informal settlements do not develop in complete isolation of governance by the state regulatory and administrative systems. Just as the formal/ informal distinction of urban areas lacks nuances, formal/ informal distinction of land ownership lacks nuances in describing the different levels of rights and tenure insecurity attributed to residents of informal settlements. Tenure security is consequently a continuum represented in the following categories, with legal rights and secure tenure first and limited rights and insecure tenure last: 1. Freeholder; 2. Leaseholder; 3. Tenant with contract; 4. Legal owner of unauthorized construction; 5. Owner of plot with unauthorized subdivision; 6. Tenant of plot with unauthorized subdivision; 7. Squatter “owner”; 8. Squatter tenant (Payne, 2001). Accordingly, the term ‘informal settlements’ lacks the nuances reflecting different modes of governance of the local administrative systems as well as the level of tenure security characterizing the individual settlement. Jenkins (2013) identifies four types of informal settlements in Maputo, Mozambique. Namely, 1) Planned formal, 2) Unplanned informal, 3) Planned informal, 4) Unplanned formal. The planned informal settlements include areas that have been planned by the local government, international agencies, or by locally commissioned planners but are not recognized by the municipality as formally planned areas. Construction in these areas is thus extra-legal, as construction permits can only be formally issued in areas with approved urban plans. These urban areas have consequently developed under limited formal governance of the state. Accordingly, these areas are informal settlements despite the planned structure of the urban fabrics. These nuances are important, as the state recognition of the urban structure determines whether ‘regularization’ (i.e., urban planning interventions to change street and plot layouts) is necessary for formalization. Furthermore, the spatial layouts and access conditions of the neighborhoods will typically condition eventual government recognition, as many public authorities have a bias against ‘organic urban forms’ and

lack of access by car (Gouverneur, 2014). Consequently, structural readjustment of unplanned informal settlements may be required prior to initiating eventual formalization processes. This has implications for unplanned informal settlements as such interventions are costly, complicated, and typically require demolition of houses, compensation for lost property, and lengthy negotiations with the residents at higher costs compared to ‘greenfield’ developments (Lamson-Hall et al., 2019). Accordingly, unregulated urban development may result in an inefficient use of resources. Informal settlements proliferate in sub-Saharan Africa in part as large segments of society lack the financial resources to comply with the urban regulation and in part, as the public authorities lack the resources to administer the comprehensive urban growth (Jenkins & Mottelson, 2020). Until both sides of this predicament are resolved, informal settlements will likely continue to proliferate. The question remains, how the legal framework should be changed in order to provide legal and secure housing for those financially excluded from the formal housing market until the urban growth stagnates or additional resources are available at both household level at large as well as in the public institutions governing the urban development? Syagga (2006) examines the inequality of land ownership and use in Kenya and argues that the legal and administrative procedures should be reviewed in order to accommodate more equitable access to land as well as transparent and accountable land management. Kombe (2005) analyzes land markets in Dar es Salaam, Tanzania, and argues that land registers should be established in the local administrative systems as decentralized urban management will facilitate more cost-effective implementation of infrastructure. Furthermore, Kombe suggests introducing transitional ‘junior titles’ as a pathway to formal land title. Kombe also suggests that structural guidelines and standards such as minimum plot-sizes and road dimensions for authenticating land transactions by the local authorities. Finally, Kombe suggests that the regularization of informal settlements should be implemented before the consolidation of the urban form. Jenkins (2000) analyzes land markets in Maputo, Mozambique, and proposes new titling procedures based on social tenure categories such as collective titling and administered in the local administrative systems. Kironde (2000) examines the land market in Dar es Salaam and suggests that informal land transactions are frequent. Furthermore, Kironde argues that the opening of the land market would make it more reliable and efficient and provide an improved basis for governance, land management, and higher generation of public revenue. Kironde (2006) examines the planning standards and administrative procedures in peri-urban Dar es Salaam. Kironde finds that high standards for plot sizes and roads lead to duplicative costs of land and vastly reduced delivery of plots. Kironde argues that comprehensive bureaucracy and unrealistic standards of urban regulation in sub-Saharan Africa exclude poor households from access to legal land and shelter. Different urban structures in Maputo, Mozambique, adapted map based on Andersen and Solien (2012) →

Jafar Unplanned

Guava Planned unoﬃcially Unplanned

Albasine Unplanned

Magoanine B Planned oﬃcially Planned unoﬃcially Unplanned

Hulene B Unplanned

Hulene A Planned unoﬃcially Unplanned

Mavalane B Unplanned

Mahotas Planned officially Planned unofficially Unplanned 3 de Fevereiro Planned officially

Laulane Planned officially Ferrovário Planned officially Planned unofficially Polana Caniço B Planned officially Unplanned Polana Caniço A Planned officially Unplanned

Railroad Main road Coast 0

Maxaquene C and D Planned unoﬃcially Unplanned

5 Km 31

The void A 60-meter wide void stretches through Kibera as a physical embodiment of the real-world implications of insecure tenure. In 2018, authorities initiated the implementation of a multi-lane highway between a suburb and a main traffic artery in western Nairobi. Regrettably, a densely populated neighborhood obstructed the passage and more than 20,000 residents were evicted. The surreal temporary public space is the stage for a host of activities not accommodated inside the spatially constrained settlement such as a friendly soccer game between local kids.

Lakes region introduced agriculture and metalworking which allowed people to settle in greater densities. In the following centuries, the Bantu slowly intensified farming and cultivation of animals over most of East Africa (Bostoen, 2018). During this process, the indigenous hunter-gatherers were submerged into the agriculture-based Bantu cultures. Bantu languages and cultures still dominate most of the mainland of East Africa to this day (Nurse & Philippson, 2006).

East Africa according to the UN geoscheme Countries emphasized in this thesis Case study areas analyzed in Part II

Historical context East Africa is a variably defined region on the African continent. According to the United Nations geo-scheme, it stretches from Eritrea in the North to Mozambique in the South, and from Mauritius in the East to Zambia in the West (United Nations Statistics Division, 1997). The region is geographically diverse and includes the African Horn, the Great Lakes Region, the Swahili Coast, and several island states in the Indian Ocean, covering 20 countries. These are characterized by great cultural and ethnic diversity as well as a multitude of different historical developments. As this thesis includes research on informal urban development in Madagascar, Mozambique, Kenya, Tanzania, and Uganda, this review of the historical developments of the region focuses primarily on these countries. Archeological findings suggest that East Africa was one of the first areas in which modern humans emerged around 200,000 years ago and the region remains the focus of studies for its role as possible ‘cradle of humanity’ (Molinaro & Pagani, 2018). Some of the earliest permanent shelters built by humans were discovered in present-day Ethiopia and estimated to be established around 30,000 years ago (Ossendorf et al., 2019). Some linguists argue that AfroAsiatic languages first emerged in the Horn of Africa in Neolithic time and spread from there to create the fourthlargest contemporary language group comprising common languages spoken in West Asia, North Africa, the Horn of Africa, and parts of the Sahel (Blench, 2006). The Horn of Africa developed in interaction with the Arabic peninsular as well as present-day Egypt and Sudan and as a result Semitic languages are spoken in Ethiopia, Somalia, Eritrea, and Djibouti today (Hodgson et al., 2014; Kitchen et al., 2009). In antiquity, early historical accounts describe the kingdoms such as D’mt and Aksum that emerged in present-day Ethiopia and Eritrea (Phillipson, 2011). During the 1st millennium BC, speakers of the original proto-Bantu language in areas around present-day southern Cameroon initiated series of migrations eastward (Holden, 2002). The Bantu expansion into much of the African Great

Early sources suggest that East African and eastern Indian Ocean trade networks were established as early as the 1st century AD (Beaujard, 2007). These may have included early trade between the East African coastal regions and the Arabic Peninsular. Around 1500 years ago Austronesian speaking people from present-day Indonesia crossed the Indian Ocean and were likely the first humans to settle in Madagascar along with the neighboring islands off the East African coast (Serva et al., 2012). Between the 6th10th century, Islamic merchants particular from Oman, the Persian Gulf, and probably India intensified their presence in East Africa (Beaujard, 2007). Bantu communities developed contact with the Arabic and Persian traders, leading to the development of the mixed Arab, Persian, and Bantu Swahili city-states. The Swahili culture that emerged from these exchanges brought many Arab and Islamic influences not seen in traditional Bantu culture. A product of the multicultural environment of the Swahili coast was the development of the Swahili language, a Bantu language that contains a number of Arabic, Persian, and Hindu loanwords due to the economic and cultural ties to Arabic, Persian, and Indian regions (Spear, 2000). The Arabic influence led to the proliferation of Islam along the coastal belt, but most Bantu remained African traditional religious adherents (Horton, 2001). Approximately 1000 years ago, Bantu speaking people migrated from the Swahili coast to Madagascar and the neighboring islands and mixed with the already established Austronesian cultures, creating the Malagasy culture in Madagascar (Gade, 1996). Approximately 600 years ago, large African Great Lakes kingdoms and states emerged, such as the Kitara, Buganda, and Karagwe kingdoms in Uganda and Tanzania (Stephens, 2013). The Portuguese were the first Europeans to explore the region, initially with the expedition led by Vasco da Gama arriving in East Africa in 1498, in search of a sea route to India bypassing the costly and unsafe Silk Road caravan routes of the Middle East and Central Asia for spice trade. The expedition was successful in reaching India, which enabled Portuguese trade with the Far East directly by sea (O’rourke & Williamson, 2009). Subsequently, Portugal established ports along the coast from southern Mozambique to Mombasa in present-day Kenya. During this period, Portugal took control of the trade of spices and slaves, which up to this point was largely controlled by the Arabic Omani Empire. During this period, the Portuguese controlled most ports and sea routes along the Swahili Coast, enabling the Portuguese to require high tariffs on items transported between Asia and Europe. However, British, Dutch, and Omani incursions curtailed the

Portuguese influence in the region during the 17th century, which declined to cover the coastal region of present-day Mozambique (Uzoigwe, 2005). Omani Imperial governance of the Swahili coast succeeded the Portuguese dominance (Vernet, 2009). However, between the 19th and 20th centuries, the entire region became a part of ‘The Scramble for Africa’, in which the major imperialist European nations conquered almost the entire continent (Pakenham, 2015). During a conference in Berlin in 1884-1885, the boundaries for ‘spheres of influence’ of different European colonialist regimes were agreed on which laid out much of the geographic partitions of contemporary nation-states in Africa (Griffiths, 1986). This development was partially prompted by the abolition of slavery and the creation of a wage-labor system, which shifted the economy towards cultivation of the land in the 19th century and expanded the previously mainly coastal colonization inland with cultivation of cash crops like coffee and tea, as well as for animal husbandry with primarily cattle and goat products (Frankema et al., 2015). The British Empire conquered parts of present-day Kenya and expanded westwards into present-day Uganda. They expanded from Southern Africa into present-day Zimbabwe and Zambia, as well as from Egypt and Sudan in the North into present-day South Sudan, and occupied parts of presentday Somalia along with taking control of several islands in the Indian Ocean. The French conquered Madagascar, along with the smaller islands nearby, Réunion and Comoros, as well as Djibouti in the Horn of Africa. The German Empire conquered a large area comprising present-day Rwanda, Burundi, and the mainland part of Tanzania. Omani presence continued in Zanzibar and the neighboring Pemba island. Italy conquered parts of present-day Somalia and Eritrea in the Horn of Africa, and unsuccessfully attempted to occupy Ethiopia, which remained independent until 1936 when it became part of Italian East Africa. After the First World War, Germany was stripped of its colonies and Britain gained mandate over present-day Tanzania, while present day Rwanda and Burundi came under Belgian control (Griffiths, 1986; Pakenham, 2015). After the Second World War, the entire African continent underwent a gradual process of decolonization and all countries gained independence from European domination. In August 1941 the US and UK agreed on the Atlantic Charter, outlining American and British goals for the world after the war. This included intentions to restore ‘self-government to those deprived of it’, which played an important role in the dismantlement of the British Empire and the decolonization of the African continent (Dulles & Ridinger, 1955). While the post-war European colonial powers were consumed with debt, growing nationalist movements formed across the continent and began to organize and challenge the colonial authorities, through both peaceful and violent tactics. The decolonization of East Africa took place in the 1950s, 60s, and 70s, with rapid transitions from colonial governments to independent nations, often marred with political turmoil (Wantchékon & García-Ponce, 2013).

Kenya gained independence from Great Britain, following a lengthy process starting with the Mau Mau rebellion in 1952, which prompted the British to give concessions, allowing the first elections to the Legislative Council in 1957, paving the way for independence in 1963. In the mid-fifties, a growing independence movement under the leadership of Tanganyika African National Union (TANU) emerged in mainland Tanzania eventually leading to the independence of the country in 1961 (Newsinger, 1981). After the Zanzibar revolution when the Arab dynasty was overthrown, main-land Tanzania and Zanzibar were unified in 1964 (Mbughuni, 2014). Uganda gained independence from Great Britain in 1962 with limited organized violence. However, subsequent to independence, the country endured internal power struggles during the Buganda crisis, leading to authoritarian governance culminating with the mass killings under the regime of Idi Amin (Wantchékon & García-Ponce, 2013). Madagascar had a growing movement for independence subsequent to the Second World War, leading to the 1947-1949 Malagasy Uprising. The growing discontent with the colonial rule prompted France to initiate transition reforms in 1956, and Madagascar gained independence in 1960 (Wantchékon et al., 2011). Unlike other European colonial powers in the region, post-war Portugal was ruled by a dictatorship, which did not seek to withdraw from its African colonies, prompting anti-colonial movements instigating the Portuguese Colonial War. In Mozambique, the war was fought between the Mozambican Liberation Movement and the Portuguese military 1964-1974, when a coup d’état brought democracy to Portugal and gave independence to Mozambique in 1975. Following independence, Mozambique was torn by a civil war 1977-1992, with the Marxist-Leninist Mozambican Liberation Movement supported by the Soviet Union and Cuba fighting against the Mozambican National Resistance supported by Apartheid South Africa, South Rhodesia, and the United States engaging in a proxy-war (Henriksen, 1978; Wantchékon & García-Ponce, 2013). The European colonization of East Africa had a significant cultural impact and played a crucial role in the formation of the contemporary states, along with the local political and administrative systems and proliferation of Christianity (Keith & Ogundele, 2007). English, French, and Portuguese remain official languages in much of the region. As the colonial borders were drawn irrespectively of local ethnic divisions, post-independence power struggles and consequent violent conflicts spread across the region in the wake of independence (Ankomah, 1970; Crocker, 1974). Furthermore, descendants of European settlers remain a part of the economic elite in most of the former colonies (Ranger, 1998). However, aside from unstable conditions in Burundi, South Sudan, and Somalia, as well as more recent violence in Mozambique, Ethiopia, and Uganda, the region is relatively peaceful today. Following independence, the power vacuum caused periods of political instability, and the scarce economic resources and limited formally trained professionals in the public sectors created fragile states with limited administrative capacity. During this time, most countries in the region underwent

developments of urbanization and many of the more centrally located informal settlements in the larger cities were established due to the lack of urban planning capacity to accommodate the influx of rural migrants to urban areas (Coquery-Vidrovitch, 1991). This development continues in most countries in the region to this day, and informal urban areas accommodate the majority of the urban population growth (UN-Habitat, 2016). However, due to the multitude of different political and historical developments in the individual contexts, the attributes of these informal urban environments vary significantly (Mottelson & Venerandi, 2020). While the land ownership in Europe was formalized through slow ‘bottom-up’ processes and gradual development of legal frameworks, the colonial authorities in Africa obtained ownership of the land through ‘top-down’ processes, often with state-sponsored violence. Much of the appropriated land was reserved for the state and ignored the local traditions for customary tenure (Lavigne Delville & Mansion, 2015). Subsequent to independence, African governments largely used the colonial legacy to consolidate the power of the elite. This included maintaining a lack of formalized land rights for the majority, enabling the state to exercise control of the land (Holden & Otsuka, 2014). In more recent years, international institutions such as the UN and the World Bank, have promoted land titling programs in order to support free-market mechanisms based on the rule of law (DurandLasserve, 2003). This development may be linked to global tendencies in which increased emphasis is placed on the liberalization of markets. Current demographic developments Aside from Antarctica, Africa is the least urbanized continent and in 2010 only approximately 40% of the African population resided in cities. However, according to demographic projections, the urban population will exceed the rural population in Africa approximately by 2030 due to migration to the cities (UN-Habitat, 2020a). Furthermore, high fertility rates contribute to the urban population growth, causing large-scale urban transformations of African cities in order to accommodate the growing urban populations. Much of this urban development occurs without effective planning, enforcement of regulation, and appropriate infrastructure provision (UN-Habitat, 2010). More than half of the urban population in sub-Saharan Africa lives in areas the UN defines as slums, characterized by substandard housing, overcrowding, insecure tenure, as well as inadequate access to safe water and sanitation. In 2010, the total population of Africa was around one billion and according to demographic projections, the total population will reach two billion by 2050 (DeSA, 2013). In the year 2000, the number of ‘slum dwellers’ in sub-Saharan Africa was approximately 130 million. In 2018, the number of slum dwellers in sub-Saharan Africa was almost 240 million and the proportion of slum dwellers in the urban population has been stagnant since 2014 (UN-Habitat, 2020b). Accordingly, the number of slum dwellers will likely continue to grow corresponding to the general urban population growth in the near future. The vast scale of the consequent need for new housing, schools, and

hospitals to accommodate the rapid urban growth will require enormous economic and natural resources. Accordingly, any global effort to enhance sustainable development should consider aspects of urbanization in sub-Saharan Africa. East Africa is the least urbanized part of Africa and thus one of the least urbanized regions of the world. However, just as the region is characterized by different historical developments and cultural diversity, the demographic developments vary across different parts of East Africa. In Ethiopia, less than 20% percent of the population resides in cities while over 60% of the population of Djibouti does so. In Rwanda, the urban population grows approximately 7% annually while the urban population of Zambia grows less than 1% annually. In Zimbabwe, less than 20% percent of the urban population resides in informal settlements while in Mozambique more than 80% of the urban population resides in informal settlements (UN-Habitat, 2010). However, despite these regional variations the region is generally characterized by low proportions of the population residing in cities, high rates of urbanization, high population growth rates, poor urban majorities, high proportion of the urban population residing in informal settlements, and limited state capacity to administer the urban growth (UN-Habitat, 2018). Some scholars attribute the high population growth rates seen in many parts of sub-Saharan Africa to poverty, low level of urbanization, low level of education, and high level of child mortality (Bongaarts & Casterline, 2013). As the population growth rates are generally lower in cities compared to rural areas, the urbanization on the continent may contribute to more sustainable population growth rates. The extensive urbanization in Africa is partly caused by ‘pull-factors’, such as new job opportunities in cities within the service and industrial sectors, as well as better access to education and health services. Meanwhile, ‘push factors’, such as decreasing job opportunities in rural areas, caused by the opening of markets and technological advancement in agriculture, have further increased the migration to cities across the continent (Njoh, 2003). Urbanization is associated with important economic and social transformations, which have brought longer life expectancy, higher levels of literacy, as well as greater access to healthcare, education, and political participation. Nevertheless, rapid unplanned urban growth without infrastructure provision threatens sustainable development at the expense of ecosystems and quality of living (Turok & McGranahan, 2013). Furthermore, the vast scale of the future urban expansion based on projections of population growth suggests that discussions on global sustainable transition will increasingly need to include aspects of urbanization in sub-Saharan Africa. As the majority of the urban population resides in informal settlements in sub-Saharan Africa, the need for improving the knowledge of how such urban areas develop should arguably be considered urgent in contemporary research on cities.

Substandard rental housing in Kibera, Nairobi, Kenya →

The moral abomination of colonialism and the centuries of exploitation of sub-Saharan Africa largely accounts for the contemporary nation-states, as well as the postindependence internal ethnic conflicts, and the unstable governance conditions under which urbanization occurred with inadequate planning and infrastructure provision. Today, more indirect forms of domination are adopted in order to maintain control of the natural resources in sub-Saharan Africa. The term ‘neocolonialism’ is used to describe the deliberate destabilization of economies and governance structures in order to exert foreign influence and control (Chomsky & Herman, 1979). Particularly, oil, gas, and mining corporations have a strong interest in weak governance structures and accountability measures in order to gain access to the resource extraction at minimal costs. Official US reports of Shell’s engagement in corruption at all levels of the Nigerian government were exposed by Wikileaks and are likely not a unique case (Sucher et al., 2011). The strategic investments in infrastructure in exchange for natural resources adopted by China are likely also characterized by widespread corruption (Brazys et al., 2017). International organizations like IMF and the World Bank have advocated for free trade policies that have opened African markets to foreign subsidized agricultural products and thereby eroded the livelihood of small-scale farmers and thus amplified the urbanization developments (Kingston, 2011). Accordingly, although more than fifty years have passed since independence swept across the African continent, the scope of the challenges facing the African cities should arguably be considered a global challenge which we all are responsible for resolving and not a prerogative in which individual nations or governments should bear the entire burden. The question remains how international organizations and foreign donors may provide support based on local democratic decision-making and accountable governance rather than enhance foreign interests in Africa.

STATE OF THE ART

This section provides an overview of the theory used in the research papers presented in Part II. Generally, the theoretical framework of the thesis relies on urban morphology and location theory. Urban morphology has origins in geography and focuses on the built environment and its development over time. Location theory has origins in economics and focuses on the relationship between markets and the arrangement of cities. Research in urban morphology has documented a correlation between human behavior and the built environment (Hillier, 2007). Research in urban economics has suggested theories explaining the mechanisms that structure the development of cities (Glaeser, 2020). The two research domains use different methods and have different academic practices. Nevertheless, both are concerned with the understanding of how cities develop. Perhaps most evidently, concerning urban density which is both a quantifiable indicator of urban form and a unit in economics. Urban density has numerous definitions and methods of measurement, quantifying urban characteristics and describing the relationship between a given area and the

↑ Relationship between population density and gasoline consumption (Newman & Kenworthy, 1989).

number of certain entities in that area (e.g. people, dwellings, services, and floor space). Glaeser (2020) argues that density is the defining property of cities and urban form is determined by transportation systems because proximity and the consequent reduced transportation costs for people, goods, and ideas are the raison d’être of cities. Different historical eras are thus associated with different urban morphologies in part due to the introduction of new modes of transportation. Early cities were established along coastlines and rivers to enable transportation by boats. Roads were structured for pedestrian movement and transportation of goods in carts. Industrialization led to rapid urbanization partially prompted by the invention of steam engines and the introduction of trains which enabled transportation of goods and people on land in larger quantities and at a higher speed. The post-war large-scale suburbanization in American and European cities were largely enabled by the development of mass-produced affordable automobiles. The urban form of cities is thus reflective of the social, economic, technological conditions of the societies that build them (Glaeser, 2020). High urban densities during the rapid urbanization in the early phase of industrialization were associated with overcrowding, spread of diseases, and risk of fires. Consequently, urban regulation was developed to counter high densities (Berghauser Pont & Haupt, 2009). New urban and architectural typologies were developed to address issues with public hygiene and access conditions. Perhaps most notably, the terraced housing in London introduced the separation of sanitation infrastructure and street space (Frasch & Wyke, 2015). Today, low densities are widely recognized as causes of environmental, social, and economic challenges. The physical outward expansion of cities characterized by low urban densities and car-dependency is

Job Market

Church Job Market Home

Home School

School

Church

Main road

↑ Relationship between urban density, mobility, and infrastructure

referred to as urban sprawl. Urban sprawl leads to increased energy consumption due to the increased need for transportation and increased surface area of buildings which amplifies the need for heating and cooling. Furthermore, the increased space consumption leads to urban expansion into green fields and arable land which could otherwise have been allocated for agriculture or nature (Dieleman & Wegener, 2004). The relationship between sustainability and urban density is a subject of discussion among urban planners and academics worldwide. Opponents of urban expansion argue that it leads to increased car-dependency, traffic congestion, higher levels of pollution and greenhouse gas emissions, loss of farmland, duplicative infrastructure costs to society, limited employment accessibility, and concentrated poverty (Angel et al., 2011). However, proponents of urban expansion argue that it leads to improved livability and satisfactory housing preferences and that that higher densities can lead to traffic congestion, greater local air pollution, more crime, noise, and overcrowding (Glaeser & Kahn, 2003). While the debate is divided, policy has largely supported curtailment of urban expansion and compact city development (Organisation for Economic Co-operation and Development, 2012). Consequently, a number of “urban containment strategies” have been developed to limit the outward expansion of urban areas through legislated urban growth boundaries and non-urban green belts (Dieleman & Wegener, 2004). Recent studies suggest that cities in Africa are undergoing rapid urban expansion with low-density developments (Mottelson, 2020b; Xu et al., 2019). Urban expansion is not unique to sub-Saharan Africa, but seen in many parts of the world and is likely linked to economic development (Angel et al., 2016). Nevertheless, inadequate investments in infrastructure and urban planning in sub-Saharan Africa

compromise the sustainability of both urban expansion and urban densification. Limited investments in infrastructure compromise mobility in peripheral low-density areas of African cities due to inadequate provision of roads, traffic congestion, insufficient public transport systems, and vast distances within the expanding cities (Satterthwaite, 2011). Simultaneously, the densification of the built-up urban fabric exacerbates problems with public hygiene in centrally located dense neighborhoods due to limited sewage and stormwater management systems along with increased risk of contamination caused by high population densities (Andreasen & Møller-Jensen, 2017). Accordingly, urban sprawl and densification discussions may be simplified to a trade-off between public hygiene and mobility in the context of sub-Saharan Africa. Costs of infrastructure are largely determined by the size of the area while the impact of implemented infrastructure is largely determined by the population density. Consequently, impact assessments and cost-benefit analyses of infrastructure investments largely depend on urban density measures. Urban density measures are thus increasingly important for African cities as they determine the impact of infrastructure investments and the negative implications of both urban expansion and densification are amplified due to the limited state regulatory and infrastructure investment capacity. The need for density discussions today can be linked to those in early industrialization, where attempts were made to describe, understand, and counter the problems of the industrializing cities. While industrialization was a driver for congested urbanization with compromised public health conditions, car-dependent development has led to comprehensive urban expansion, resulting in overconsumption of resources. Considering the global climate crisis, it is arguably imperative to consider ways to

Rental housing in Kibera, Nairobi, Kenya

minimize the impact on the environment, enhance sustainable development, while improving human livelihood in African cities. Consequently, discussions on urban density remain relevant for policy-makers and urban planning practitioners today. Solutions for addressing the increased space consumption developed in Europe or North America are likely less applicable to the sub-Saharan African Cities as the public sectors lack the resources to implement comparable solutions. However, the environmental, economic, and social significance associated with the scale of urban development in sub-Saharan Africa thus suggests a need for research on the physical dimensions of the challenges linked to the proliferation of informal settlements. Location, Urban Density, and Property Prices Different urban models have been developed in order to describe the relationship between location, land value, land use, and urban densities. Von Thünen (1966) developed one of the first models with a simple representation of a monocentric city explaining the distribution of prices and land use around a city. The concentric zone model further elaborated on the concept of concentric land use rings, highlighting the relation between land use, land values, built densities, and distance to a city center (Burgess, 2008). Haig (1926) proposed the ‘costs of friction hypothesis’ arguing that land values are determined by transport costs to the city center and that these determine land use and densities. Hoyt (1939) proposed the sector model, arguing that cities do not develop in concentric circles but rather in different sectors surrounding the Central Business District (CBD). These sectors radiate outward along axes and are driven by transportation routes from the city center. Harris and Ullman (1997) proposed the multi-nuclei model, arguing that sub-centers are growth points within the city, due to profit maximization through a combination of costs of rent, transportation, and labor. Alonso (2013) argues that households, commercial establishments, and industries compete for locations, creating segregated land use, as households will not pay commercial and industrial land prices for central locations. Smith (1978) argues that urban amenities such as low crime, clean air, accessibility to work, the local quality of education, and local taxes influence land prices. Many of these concepts were combined in the Spatial Equilibrium Model, first proposed by Samuelson (1952) and later advanced through a multitude of contributions, notably by Alonso (2013), Mills (1967), and Muth (1969). The Spatial Equilibrium Model assumes that welfare is equalized across space. Exogenous differences across space in productivity, amenities, and the construction sector drive differences in density, incomes, and home prices. If two identical neighboring houses are located on each side of the school district boundary and the quality of the two schools differs substantially it will offset the market values of the houses. Similarly, peripheral land costs less than centrally located land. The welfare is equalized as the price is lower for the house in the bad school district. Glaeser and Gottlieb (2009) argue that changes in house prices do not naturally represent an increase in national wealth since the increase in asset values has been offset by an increase in the price of securing a basic necessity. Bertaud (2018) argues that density

↑ Distribution of population densities in different cities (Bertaud, 2018)

is an indicator of land consumption, reflecting the equilibrium between supply and demand for land in a specific location. Population density is thus an indicator dependent on market parameters, mainly household income, land supply elasticity, and transport speed and cost. This implies that housing costs plus transport costs are constant across space, which means that housing costs will decline as transport costs rise with distance to the city center. Accordingly, centrally located land is more valuable due to the decreased transportation costs to access the city center. In order to maximize the use of space, land users construct multi-story buildings on valuable land. These market mechanisms thus explain why centrally located areas are characterized by high densities and peripheral areas are characterized by low densities. Gollin, Kirchberger, and Lagakos (2017) used the Spatial Equilibrium model to account for wage gaps and differences in household amenities between rural and urban areas across 20 African countries. Gulyani, Bassett, and Talukdar (2014) suggest that location, access to infrastructure, and quality and size of housing drive costs of rent in informal settlements, based on a study on household conditions in slums in Dakar, Senegal, and Nairobi, Kenya. The study thus supports the Spatial Equilibrium Model, underscoring that informal land markets work similarly to formal land markets. The study found that tenants have a lower quality of housing, smaller dwellings, and lower levels of access to infrastructure. The study found significant inter-city differences in quality and price of accommodation, which the authors do not account for (e.g. by ascribing it the “city effect”). This underpins that the relation between property prices, location, and urban density of informal settlements in sub-Saharan Africa remains under-researched as argued by Visagie & Turok (2020).

Unsanitary urban conditions in Antohomadinika, Antananarivo, Madagascar →

Urban morphology of informal settlements Urban morphology is the study of the form of human settlements with the aim of describing their spatial structures and understanding the process of their development (Moudon, 1997). Muratori (1959) argues that the structure of a city is understood historically focusing on the diachronic processes of transformations through the ‘operative history’. Furthermore, Muratori introduces a classification of building typology and adjacent open spaces as the basis of understanding of the development of the city (Moudon, 1994). Conzen (1960) defines a town plan as a topographical arrangement of street-systems comprised of streets, street-blocks comprised of plots, and block-plans comprised of buildings. In addition, Conzen introduces a methodology for town-plan analysis focusing on the formative processes of the pattern of streets, pattern of building forms, and pattern of land use in order to gain an understanding of the socio-economic conditions of the development of the city. Kostof (1991) further contributes to the research field by further emphasizing that different urban morphologies evolved in different historical periods which underpins the relationship between urban form and social, economic, technological conditions of society. Rapoport (2016) outlines three different views on the relationship between human behavior and the physical environment. Namely, that A) the physical environment determines human behavior (environmental determinism); B) the physical environment provides possibilities and constraints within which people make choices (possibilism); C) the physical environment provides different options and some are more probable than others (probabilism). Urban regulation usually includes multiple indicators of urban form such as building height, Floor Area Ratio (FAR), and Ground Space Index (GSI) (Usui, 2020). FAR refers to the total floor area divided by the total sample area (typically a block of private plots surrounded by streets). This metric highlights the density of the built environment. GSI is also known as building coverage and refers to the total building footprint divided by the total sample area (typically a block). This metric highlights the level of open space. Similarly, public space ratio refers to the total public space divided by the total sample area (typically a neighborhood). This metric highlights the level of public space. However, the inability of such metrics to convey more information than the individual indicators without relational information has prompted researchers to develop models linking density to other indicators of urban form capable of producing more in-depth descriptions of spatial properties. Studies of typomorphology introduced a deductive quantitative approach to understanding the relationship between urban programs and spatial properties, such as the land available, the buildings located on this land, and the roads required to serve them (March & Martin, 1972). Rådberg (1996) suggests a quantitative multi-indicator classification of urban types using GSI, FAR, and building heights as indicators of urban form. Similarly, the Space Matrix treats density as a multivariable phenomenon, in a three-dimensional diagram, with the three fundamental indicators: intensity (FSI), compactness (GSI), and network density (N) on each axis

(Berghauser Pont & Haupt, 2009). Hillier and Hanson (1984) use mathematical representation and analysis of street networks, which was later developed into a variety of algorithms and software applications for analysis of urban form, such as Space Syntax (Hillier, 2007). Multiple methods for street network configuration analysis have emerged, such as node degree centrality, closeness, and betweenness (Porta et al., 2010). Many of these methods for configurational analysis of street networks have origins in graph theory in mathematics and are widely applied in the social sciences for social network analysis (Chiesi, 2001). Node degree centrality measures the number of nodes that each node is connected to (the number of streets leading into each intersection) and measures the involvement of the node in the network (Opsahl et al., 2010). Closeness (i.e., integration in space syntax) is a measure of the number of transitions required from one street to reach all other streets in the network using the shortest paths (Vaughan, 2007). Betweenness is a measure of the number of times a node (i.e., street intersection) acts as a bridge along the shortest path between two other nodes (Porta et al., 2006). Correlation between street network configuration and human behavior, such as frequency of crime, intensity of commercial activities, and movement of people has been documented through the use of these applications (Scoppa & Peponis, 2015; Kim & Hipp, 2019; Hajrasouliha & Yin, 2015). However, configurational analysis does not account for other morphological aspects such as built-mass density thus limiting the scope of such methods (Ratti, 2004). A number of studies have documented the correlation between urban density measures and energy consumption, mobility, and costs of infrastructure provision which underpins the importance of such measures (Álvarez et al., 2014; Horner, 2013; Newman & Kenworthy, 1999; Trepci et al., 2020). Other studies have documented the correlation between urban tree canopy cover and urban microclimate, education levels, and median household income in urban areas (Elmes et al., 2017; Heynen & Lindsey, 2003; Schwarz et al., 2015). Gehl (2011) documents that residents of low-rise highdensity areas are acquainted with more of their neighbors than residents of tower blocks thereby suggesting a causation between building typologies and character of the social life between the buildings. The increased availability of morphological data and computational power have enabled more complex quantitative forms of analysis and the emergence of urban morphometrics using a systematic measurement of multiple configurational and urban density measures as morphological indicators (Dibble et al., 2019; Fleischmann, 2019). Studies using such methods have found a correlation between urban form and public health, energy consumption, and livability of neighborhoods (Marshall et al., 2014; Ratti et al., 2005; A. Venerandi, 2017). However, limited studies have investigated the urban morphology of informal settlements, particularly in the context of subSaharan Africa. Hillier et al (2000) examine informal settlements in Santiago, Chile and suggest that spatial and locational factors drive the development and consolidation of informal settlements. The study suggests that edge oriented commercial activity and

Closeness analysis of street network Low

High

Betweeness analysis of street network Low

Building coverage (GSI) Low

Node degree analysis of street network Dead-end streets Three-street intersections Four-street intersections

High

Block size High

Small

Floor area ratio (FAR) Large

Low

High

↑ Urban form analysis of Katanga, Kampala, Uganda

consequent inclusion in the wider local economy is determined by the levels of spatial integration within the surrounding urban fabric and is significant for consolidation of the built form of informal settlements. However, Hillier et al primarily focus on features of the street network, thus missing further aspects of the built environment. Davis (2006) suggests a typological classification of informal settlements based on location, formal/informal conditions and proximity to job opportunities. Smith & Jenkins (2015) examine the development of informal settlements in Huambo, Angola and suggest that the urban growth entails decreasing household sizes, plot subdivision, increasing provision of rental accommodation, and increasing density of land occupation by buildings. Dovey et al. (2020) trace the development of street networks and buildings in multiple informal settlements, demonstrating the range of morphologies characterizing these areas. They analyze building types, plots, blocks, streets, and lanes in order to highlight how habitable land, affordable housing, and public space is produced in different contexts. However, limited quantitative studies have investigated the urban form of informal settlements. Accordingly, this lack of knowledge limits the efficacy of urban planning and policy in addressing the wide-ranging issues characterizing contemporary urban development in sub-Saharan Africa.

OVERVIEW OF RESEARCH PAPERS

This research project was initially conceived out of a curiosity of how urban form is produced in informal settlements. Why do centrally located informal settlements in major cities in different East African countries have fundamentally different spatial properties? What factors influence the development of urban form of informal settlements? And how can knowledge of the processes conditioning the development of informal settlements improve the basis for developing effective urban planning interventions and policies for such areas? The project sought to answer these questions by examining a number of case studies across East Africa. Initially, the project sought to develop a model that described the different factors that influence the development of spatial structures in informal settlements such as governance, urban population size, economy, geography, culture, and local historical development. However, as more and more data were collected, processed, and analyzed it became apparent that local governance and more specifically, the extent of which informal settlements are allowed to proliferate is the key factor determining the urban form of informal settlements in East Africa. This is elaborated in the paper A New Hypothesis on Informal Land Supply, Livelihood, and Urban Form in Sub-Saharan African Cities (Mottelson, 2020a) in which all of the abovementioned factors are discussed based on case studies in four major cities in East Africa. The remaining five papers focus on more particular aspects of the urban form of informal settlements. The paper On the Impact of Urban Planning of Informal Settlements in Sub-Saharan Africa (Mottelson, 2021) examines the long-term impact of urban planning on the development of urban form of informal settlements in Maputo, Mozambique. The papers A Fine-Grain MultiIndicator Analysis of the Urban Form of Five Informal

Settlements in East Africa (Mottelson & Venerandi, 2020) and Urban Form of Informal Settlements in East Africa: A Taxonomy of Block Types (Venerandi & Mottelson, 2021) use statistical methods to examine and describe the spatial properties of informal settlements in East Africa. The papers Urban Densification of Informal Settlements in Sub-Saharan Africa: An Analysis of Recent Developments in Maputo, Mozambique (Mottelson, 2020b) and Understanding Density in Unplanned and Unregulated Settlements of Peri-urban Africa: A Case Study of Maputo, Mozambique (Jenkins & Mottelson, 2020) analyze and discuss the relationship between centrality and urban densities of informal settlements. Most of the papers include policy responses based on the findings. Accordingly, the research papers presented in this thesis provide insights into what key characteristics define the spatial properties of informal settlements in East Africa as well as an analysis of why these have emerged, and a discussion of how to use this knowledge to enhance the efficacy of urban planning and policy in confronting the multi-faceted issues characterizing the informal urban development in the region. The paper A New Hypothesis on Informal Land Supply, Livelihood, and Urban Form in Sub-Saharan African Cities (Mottelson, 2020a) presents an analysis of informal urban land use in four major cities in East Africa, as well as an analysis of urban form and household conditions in a case study area in each city. The study found large variations in informal urban land use across the four examined cities. Accordingly, attitudes and practices towards informal urban development likely vary among authorities across the region. The study found that centrally located settlements in the four examined cities have diverse urban form characteristics. More specifically, the study found diverse built densities and public space conditions. The study suggested that the public space ratio in informal settlements is linked to average block size. The study found that built densities and public space ratio are not interdependent. This suggests that public space ratio is largely determined by the governance of the early formation of the settlement when blocks are established and the subsequent governance determining the level of street encroachment. The study found higher built densities in the case study areas located in the examined cities characterized by limited informal land use. The study also found a high proportion of tenants, more widespread overcrowding, and lower levels of access to water and sanitation in the examined cities with limited informal urban land use. Based on these findings, the study proposed a novel hypothesis on informal urban development in cities in sub-Saharan Africa characterized by majorities financially excluded from the formal housing market. The hypothesis is structured in three hierarchical layers. First, the governance practice decisively influences the informal land supply. Second, market mechanisms influence the price of informal land. Third, the price of informal land influences household conditions and the development of urban form. The hypothesis is underpinned by empirical findings showing consistency between theory and data. However, the relation between the property prices, location, and urban density of informal settlements in sub-Saharan Africa remains under-researched

↑ Maxaquene, Maputo, Mozambique

↑ Kibera, Nairobi, Kenya

↑ Antohomadinika, Antananarivo, Madagascar

(Visagie & Turok, 2020). Accordingly, further studies are needed to corroborate the hypothesis. The paper argues that informal urban development proliferates when the administrative capacity of the state is limited and large parts of the population have too limited resources to comply with regulations. The paper argues that enforcement of the law through eviction of the informal settlements leads to worse living conditions for the population financially excluded from the formal market. However, this does not mean that public policy should enhance the proliferation of informal urban development. Conversely, the paper argues that the requirements for what is considered formal should be changed so that they require fewer resources in public administration and are less costly for the general population. The paper On the Impact of Urban Planning of Informal Settlements in Sub-Saharan Africa (Mottelson, 2021) compares the urban form of three centrally located unplanned informal settlements with three adjacent planned informal settlements in Maputo, Mozambique in order to assess the long-term impact of urban planning on the urban form of informal settlements. The study includes field interviews on household conditions in each of the six cases in order to assess the relationship between the structure of urban fabric and socio-economic conditions in informal settlements. The study found significant variations between planned and unplanned case study areas in both urban form and household conditions. All three planned areas feature higher built density, more compact urban form, higher proportions of public space, higher average street width, smaller average dwelling size, smaller average household size, and higher proportion of tenants compared to the adjacent respective unplanned areas. Furthermore, on average the urban tree coverage, the levels of household access to electricity and sanitation, and average block size were lower in the planned areas compared to the unplanned areas. Accordingly, the study suggests that urban planning has a long-term impact on both urban form and household conditions in contexts with limited state governance of the urban development. The study suggests that planned urban areas are generally seen as more desirable in Maputo which likely offsets the market value of land in these areas thereby resulting in homeowners with more resources moving into the planned areas compared to the unplanned areas. The study suggests that this mechanism accounts for the higher proportion of tenants in the planned areas compared to the unplanned areas as homeowners in planned areas thereby have more resources for investments in rental housing units. Accordingly, the study suggests that higher levels of household resources in planned areas partially account for the higher levels of built density seen in the planned areas. The study argues that smaller average plot sizes and simpler plot geometries further contribute to the higher urban densities in the planned sample areas. The study found higher levels of public space and average street width in planned areas which the study argues is a direct outcome of urban planning. The study found lower levels of urban tree canopy cover in the planned areas. The study suggests that this may be an outcome of higher levels of built densities, higher levels of public space, or more household resources.

The study argues that urban planning leads to improved mobility and increased feasibility of investments in infrastructure. Accordingly, the study argues that urban planning should be given increased policy priority, particularly in peripheral areas where the urban form is not consolidated yet. The study argues that a strategy for increasing the urban tree canopy cover in informal settlements should be developed in order to improve the urban micro-climate, increase bio-diversity, and improve rain-water infiltration. Finally, the study argues that the local neighborhood administration should be provided capacity building in urban governance and more economic resources for investments in locally determined priorities. The paper Urban Densification of Informal Settlements in Sub-Saharan Africa: An Analysis of Recent Developments in Maputo, Mozambique (Mottelson, 2020b) examines built densification of three unplanned informal settlements and developments of population densities in Maputo, Mozambique. The study is based on analysis of satellite images and census data from 2007 and 2017. The study found increasing built densities in all three case study areas and decreasing population densities in two case study areas. Accordingly, increasing built densities do not necessarily lead to increasing population densities. The study corroborates recent studies suggesting that the urban population growth in sub-Saharan Africa is mainly accommodated through urban expansion (Xu et al., 2019). The study found a limited variation of population densities and built densities despite different distances to the city center. The paper argues that this is caused by limited investment capacities of the landholders and large informal land supply. The paper suggests that centrality is less significant for the development of built densities in informal settlements where residents hold the land due to limited investment capacity. The paper argues that policy-makers should prioritize the establishment of roads in peripheral areas financed through road-pricing in order to curb the urban expansion and improve the resiliency of peripheral areas. The paper A Fine-Grain Multi-Indicator Analysis of the Urban Form of Five Informal Settlements in East Africa (Mottelson & Venerandi, 2020) presents a morphological analysis at the block level of five informal settlements in East Africa (Antohomadinika, Kibera, Katanga, Hananasif, and Maxaquene). Outcomes show the emergence of a general pattern across the settlements (i.e., street networks are characterized by organic layouts based on bifurcations such as Y- and T-junctions), a feature found in informal settlements settlements. Furthermore, most blocks in Antohomadinika, Kibera, and Katanga were found to be densely built with limited open space. The paper suggests that this is a result of stronger forms of control of the informal land market, speculative housing markets, and the relative distance to the CBD. Hananasif and Maxaquene were not only found to be statistically different from the above-mentioned group of settlements, but also to each other. More precisely, most blocks in Hananasif were slightly denser than the blocks in Intimate street life in Hananasif, Dar es Salaam, Tanzania →

Maxaquene. Counterintuitively, although Hananasif possessed these features, it is characterized by more public space than Maxaquene. This was suggested to be the result of local administration practices and a ‘slum upgrading’ initiative aimed at enlarging the streets of the settlement. The proposed methodology overcomes limitations of previous works, especially concerning replicability, scale, and robustness. It can be applied to further cases to gain a better understanding of local features of informal settlements and eventually guide ad-hoc strategies, which could deliver more effective urban planning and policies. The paper argues that limited informal land supply, partly caused by government control of the land market, leads to higher costs of accommodation and consequently fewer resources for private investments in infrastructures and home improvements. This, in turn, leads to proliferation of slum conditions in informal settlements, such as overcrowding and inadequate access to water and sanitation. The paper thus argues that accepting some modes of informal urban development will likely improve living conditions, as it would increase the informal land supply and thereby decrease the price of accommodation and free resources for investments in basic infrastructures. On this basis, the paper argues that governments should rather focus on guiding developments of informal settlements and invest in infrastructures rather than evicting them. This could be pioneered through state-financed allocation of small plots with leasehold titles on government-owned land, with allocation of sufficient street space, common water and sanitation units, and local guidance for auto construction without enforcement of the building code. The paper Urban Form of Informal Settlements in East Africa: A Taxonomy of Block Types (Venerandi & Mottelson, 2021) presents a taxonomic study at a fine level of spatial granularity of the urban form of five informal settlements, located in major cities of sub-Saharan Africa. More specifically, a k-means clustering is applied to eight indicators of urban form computed at block level, for each of the settlements under examination. The clustering analysis identified 10 different block types associated with distinctive features, such as blocks on public spaces (i.e., small, densely built, abundant public open space), fringe blocks (i.e., medium-sized, sparsely built, low local connectivity), blocks in the making (i.e., large, sparsely built, high levels of through movement at settlement level). While these findings may not cover all block types in informal settlements due to the limited number of cases, the taxonomy presents one of the first attempts to develop more generalizable quantitative descriptions of the urban form of informal settlements in East Africa. The paper Understanding Density in Unplanned and Unregulated Settlements of Peri-urban Africa: A Case Study of Maputo, Mozambique (Jenkins & Mottelson, 2020) analyze developments of built densities over a ten-year interval (2007-2017) using satellite photos of three case study areas in informal settlements compared with developments of population densities based on census data. The studies found

increasing built densities in all three sample areas and decreasing population densities in the two more centrally located case study areas. The census data showed only 1% population growth within the municipality and more than 60% population growth in the larger metropolitan area over the ten-year interval. Accordingly, the two papers suggest that the rapidly growing urban population of Maputo is primarily accommodated through urban expansion. This could be seen as an indicator of unsustainable urban development and should arguably thus be considered a policy priority. The papers argue that the state capacity to control the urban growth will likely remain limited and efforts to curb the urban expansion should thus be focused on alternative policy measures to land use regulation. The papers suggest that such measures could include road pricing and construction of demonstration compact housing typologies which local residents could replicate.

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Dysfunctional infrastructure in Kibera, Nairobi, Kenya

63access Boiled water is poured into jerrycan and sold for drinking as to safe water is inadequate in Katanga, Kampala, Uganda

land Article

A New Hypothesis on Informal Land Supply, Livelihood, and Urban Form in Sub-Saharan African Cities Johan Mottelson Institute of Architecture, Urbanism and Landscape, Royal Danish Academy, 1435 Copenhagen, Denmark; jmot@kadk.dk; Tel.: +45-30-13-10-01 Received: 23 October 2020; Accepted: 5 November 2020; Published: 7 November 2020

Abstract: In sub-Saharan Africa, the urban majorities are financially excluded from the formal housing markets and reside in informal settlements. Limited knowledge on the development of informal settlements compromises the efficacy of urban planning and policies targeting such areas. This study presents an analysis of informal urban land use in four major cities in East Africa, as well as an analysis of urban form and household conditions in a case study area in each city. The study found more compact urban form, higher levels of tenants and overcrowding, and lower levels of access to water and sanitation in the examined cities with limited informal urban land use. The study argues that government repression of informal urban development decreases informal land supply and leads to increased competition in the informal land market, causing higher costs of accommodation and consequent fewer household resources for investments in infrastructure and thereby more compromised livelihood. The study argues that governments should accept some modes of informal development, simplify the urban development administration processes, and use technological innovation in land surveys and management, in order to lower costs of accommodation and improve livelihoods for the urban majority financially excluded from the formal housing market in East Africa. Keywords: informal settlements; informal land supply; sub-Saharan Africa; urban form; livelihood; slums

1. Introduction Informal settlements are urban areas typified by lack of state control [1]. This typically encompasses lack of urban planning, construction without formal permits, and lack of formal land titles [2]. In sub-Saharan Africa, the urban majority resides in informal settlements, due to high population growth rates, high rural to urban migration, poor urban majorities, and limited state capacity to administer the urban growth since independence [3]. The proliferation of informal urban development will likely continue in the coming decades due to a continuation of these conditions. Knowledge about the size and spatial distribution of a human population in relation to the built environment is essential for understanding social, economic, and environmental issues and is thus important for developing efficient urban planning and policy [4]. Limited knowledge of the formation and development of informal settlements limits the capacity to develop effective policy and urban planning in sub-Saharan Africa [5]. This paper argues that supply of informal land is essential for the development of livelihood and urban form in informal settlements in sub-Saharan Africa. The paper proposes a provisional hypothesis describing how decreased supply of informal land leads to higher prices in the informal land market due to increased competition. This results in increased costs of accommodation in the informal housing sector and a higher share of income allocated for housing for low-income groups resulting in compromised livelihoods. In parallel, the increased competition incentivizes increasing the density

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of the built environment within the informal settlements, resulting in a more compact urban form. The hypothesis is supported by data from various sources showing consistency between the hypothesis and observations. The proposed hypothesis may have significant policy implications, as enforcement of the law in regard to restricting informal urban development leads to compromised livelihoods for the urban poor. Consequently, the standards for what constitutes formal urban development in large parts of sub-Saharan Africa should arguably be subject to revision. 2. Location, Urban Density, and Property Prices Urban density has numerous definitions and methods of measurements, quantifying urban characteristics and describing the relationship between a given area and certain quantifiable entities in that area, e.g., people, dwellings, services, and floor space. High urban densities are advocated as benefitting sustainability, resilience, and economic growth, as well as cutting the costs of service delivery and infrastructure [6,7]. Recent studies suggest that cities in Africa are undergoing rapid urban expansion with low-density developments [8,9]. Urban expansion is not unique to sub-Saharan Africa, but seen in many parts of the world and is likely linked to economic development [10]. Nevertheless, inadequate investments in infrastructure and inadequate urban planning in sub-Saharan Africa compromise the sustainability of both urban expansion and urban densification, as peripheral urban expansion decreases mobility due to inadequate roads and public transport, while central urban densification compromises public health due to inadequate stormwater infrastructure and inadequate access to water and sanitation [11,12]. Different urban models have been developed in order to describe the relationship between location, land value, land use, and urban densities. Von Thünen [13] developed one of the first models with a simple representation of a monocentric city explaining the distribution of different land use around a city. The concentric zone model further elaborated the concept of concentric land use rings, highlighting the relation between land use, land values, built densities, and distance to a city center [14]. Haig [15] proposed the costs of friction hypothesis, arguing that land values are determined by transport costs to the city center and that these determine the land use and densities. Hoyt [16] proposed the sector model, arguing that cities do not develop in concentric circles but rather in different sectors surrounding the central business district (CBD). These sectors radiate outward along axes and are driven by transportation routes from the city center. Harris and Ullman [17] proposed the multi-nuclei model, arguing that sub-centers are growth points within the city, due to profit maximization through combination of costs of rent, transportation, and labor. Alonso [18] argues that households, commercial establishments, and industries compete for locations, creating segregated land use, as households will not pay commercial and industrial land prices for central locations. Smith [19] argues that urban amenities such as low crime, clean air, accessibility to work, the local quality of education, and local taxes influence land prices. Many of these concepts were combined in the spatial equilibrium model, first proposed by Samuelson [20] and later advanced through a multitude of contributions, notably by Alonso [18], Mills [21], and Muth [22]. The spatial equilibrium model assumes that welfare is equalized across space. Exogenous differences across space in productivity, amenities, and the construction sector drive differences in density, income levels, and home prices. Glaeser and Gottlieb [23] argue that increasing house prices do not naturally represent an increase in national wealth since the increase in asset values has been offset by an increase in the price of securing a basic necessity. Bertaud [24] argues that density is an indicator of land consumption, reflecting the equilibrium between supply and demand for land in a specific location. Population density is thus an indicator dependent on market parameters, mainly household income, land supply elasticity, and transport speed and cost. This implies that housing costs plus transport costs are constant across space, which means that housing costs will decline as transport costs rise with distance to the city center. Gollin, Kirchberger, and Lagakos [25] used the spatial equilibrium model to account for wage gaps and differences in household amenities between rural and urban areas across 20 African countries. Gulyani, Bassett, and Talukdar [26] suggest that location, access to infrastructure, and quality and size of housing drive

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costs of rent in informal settlements, based on a study on household conditions in slums in Dakar, Senegal, and Nairobi, Kenya. The study thus supports the spatial equilibrium model, underscoring that informal land markets work similarly to formal land markets. The study found that tenants have lower quality of housing, smaller dwellings, and lower levels of access to infrastructure. The study found significant inter-city differences in quality and price of accommodation, which the authors do not account for, e.g., by ascribing it the “city effect”. This underpins that the relation between the property prices, location, and urban density of informal settlements in sub-Saharan Africa remains under-researched, as argued by Visagie and Turok [27]. Colin and Woodhouse [28] provide an overview of the literature on land markets in sub-Saharan Africa and argue that empirical studies which economic models rely on remain sparse. Kombe [29] examines land use trends in peri-urban Dar es Salaam, Tanzania, and argues that the emerging land use pattern indicates a discrepancy between the planning practices and land value theories. Nkurunziza [30] examines informal housing markets in Kampala, Uganda, and argues that informal settlements provide large quantities of housing in part due to social legitimacy. Syagga [31] examines the inequality of land ownership and use in Kenya and argues that the legal and administrative procedures should be reviewed in order to accommodate more equitable access to land as well as transparent and accountable land management. Kironde [32] examines the land market in Dar es Salaam and suggested that informal land transactions are frequent. He proceeds to argue that opening of the land market would make it more reliable and efficient and provide an improved basis for governance, land management, and higher generation of public revenue. Kironde [33] examines the planning standards and administrative procedures in peri-urban Dar es Salaam. He finds that high standards for plot sizes and roads lead to duplicative costs of land and vastly reduced delivery of plots. He argues that comprehensive bureaucracy and unrealistic standards of urban regulation in sub-Saharan Africa exclude poor households from access to legal land and shelter. Wallace and Williamson [34] describe the emergence of land markets as five evolutionary stages, in which higher levels of rights to the land and more flexible modes of land transactions are provided in the latter stages. The proliferation of informal settlements in sub-Saharan Africa is in part a result of a lack of resources in the public sectors to administer the urban development and in part a result of a lack of resources at the household level to comply with the regulatory standards. The lack of public capacity to administer the urban growth in sub-Saharan Africa leads to widespread lack of land titles along with a lack of developed, approved, and implemented urban plans [35]. As construction permits require land titles and approved urban plans, legal construction is thus unattainable for residents of such areas. Provision of drawings and paperwork for formal construction permits requires specialized professionals and thus increases costs of construction. Requirements of the building code, such as minimum structural dimensions, floor to ceiling height, and access conditions, increase costs of construction. Complying with urban regulation thus increases costs and without state-subsidized alternatives, formal housing is unattainable for the urban majorities due to lack of financial resources [27]. The urban majorities in sub-Saharan Africa are thus financially excluded from the formal legal housing market, reflecting a failure of the formal housing markets to provide affordable accommodation [10]. Consequently, the lower levels of public administration have developed informal systems of provision of construction permits without formal basis in the law as well as acceptance of construction not complying with the building code, thus lowering the costs of construction and providing more affordable accommodation for the urban poor [36]. Informal settlements are thus legal gray zones in which the local public administrations engage in extra-legal practices. The spatial extent of the areas governed through such extra-legal practices varies greatly from country to country and from city to city. In some cases, authorities adopt policies of evicting residents of informal settlements due to the extra-legal conditions of construction without permits and lack of land titles [37]. In other cases, governments grant some property rights protecting the residents of informal settlements along with de facto acceptance of the extra-legal practice to a greater extent [38]. This is exemplified by Figure 1, showing the spatial extent of informal settlements in Maputo, Mozambique,

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and Nairobi, Kenya. More specifically, the share of informal land use is almost 30 times as high in Maputo compared with Nairobi. Government repression of informal urban development decreases informal land supply, confining the space attainable for the poor majorities and leading to higher Land 2020, 9, x FOR PEER REVIEW 4 of 24 population densities within the informal land mass. Conversely, government acceptance or negligence confining the spaceurban attainable for the poor majorities and leading to higher population densities of proliferation of informal development will increase informal land supply and thus provide within the informal land mass. Conversely, government acceptance or negligence of proliferation of more space for those excluded from the formal land mass, leading to lower population densities of informal urban development will increase informal land supply and thus provide more space for the informal those landexcluded mass. from Government attitudes towards informal urban development, the formal land market, leading to lower population densities of the informalas well as the land market. Government attitudes towards informal urban development, as well as capacity to capacity to control it, will thus partially determine the population densities ofthethese areas. control it, will thus partially determine the population densities of these areas.

Figure 1. Informal land use within the administrative boundaries of the four examined cities. Figure 1. Informal land use within the administrative boundaries of the four examined cities.

This paper presents a provisional hypothesis outlining how informal settlements develop based

This paper presents a provisional hypothesis outlining informal based on analysis of various data sources. The hypothesis proposeshow that the supply ofsettlements informal land develop is on analysis of various data sources. The hypothesis proposes that the supply of informal land is essential for understanding urban form and livelihood in the context of sub-Saharan Africa where cities are growing rapidly and the urban majority is financially excluded from the formal housing market. The hypothesis suggests that government constraints on informal land supply increase competition on the informal land market which, in turn, results in higher land prices. The higher prices of informal land further exclude low-income groups from holding land and thus lead to an increased share of tenants. Furthermore, the higher prices of informal land also lead to increased costs

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of rent which, in turn, lead to a larger share of household resources consumed for basic housing for low-income groups. This leads to fewer resources for other basic necessities, resulting in compromised livelihood. Additionally, the size of the informal land mass will determine the population density of the informal settlements at large. Decreased informal land supply will thus result in increased population densities. As limited informal land mass and informal land supply increase costs of rent, this also leads to decreased average dwelling sizes in the informal housing sector. Increased numbers of tenants provide additional income for the landholders, increasing the investment capacity for construction. Consequently, the decreased informal land supply leads to increasing built densities and a more compact urban form. The hypothesis is structured in three hierarchical layers. First, the informal land supply is partially determined by governance practice. Second, the costs of accommodation are partially determined by the informal land supply through market mechanisms. Third, urban form and livelihood are partially determined by the costs of accommodation. This paper presents an analysis of data from four major cities in East Africa underpinning this “Informal Land Supply Hypothesis” by showing consistency between theory and observations. The data include self-produced field interviews and high-resolution spatial data from four case study areas as well as land use data from various sources and references to a number of other studies on the cases under examination. The hypothesis is novel as it suggests that enforcement of the law through evictions of informal settlements and curtailment of informal urban development leads to compromised livelihood for low-income groups. Consequently, the study argues that modes of informal urban development should be accepted. 3. Materials and Methods The paper utilizes mixed methods based on publicly available land use data, self-produced geo-spatial surveys, and field interviews on household conditions, along with a literature review of previous studies on household conditions in the examined contexts. This includes a qualitative assessment of municipal level informal urban land use data from various sources. Furthermore, it includes a quantitative and qualitative assessment of the urban form of a centrally located informal settlement in each of the four cities based on the self-produced high-resolution geo-spatial surveys. Finally, the study includes a quantitative assessment of household conditions in each case study area based on field interviews, along with a literature review of previous studies on household conditions in each context. This section outlines the methods used to obtain, process, and analyze the data. The selection criteria for the four examined cities were based on the size of the cities and availability of informal land use data. The examined cities are the largest in their respective contexts and are characterized by the largest concentrations of populations excluded from the formal housing market. Accordingly, these cities were evaluated to provide the best cases for analysis of informal urban development. Furthermore, the informal land use data were essential for carrying out the analysis. Accordingly, the availability of informal land use data for the examined cities was decisive in the selection of cases. The individual settlements examined in this paper were selected based on location and urban form. Centrally located informal settlements were selected for the study as these feature some of the densest urban form in each respective context. As all the settlements are centrally located, centrality does not account for the variations in the urban form and household data. As all the settlements are unplanned, the urban planning history of the case study areas does not account for the variations in the data in the urban form and household data. The examined case study areas include Hananasif, Dar es Salaam, Tanzania; Katanga, Kampala, Uganda; Kibera, Nairobi, Kenya; and Maxaquene A, Maputo, Mozambique. 3.1. Acquisition and Analysis of Informal Urban Land Use Data Informal urban land use data from various sources were utilized to identify and analyze the spatial extent of the informal settlements in the four cities under examination. Sliuzas, Hill, Lindner, and Greiving [39] studied the urban land use of informal settlements in Dar es Salaam in 2002. A GIS data set from the study was obtained from the NASA Socioeconomic Data and Applications Center (SEDAC)

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website (www.sedac.ciesin.columbia.edu/). Municipal authorities surveyed urban land use of informal settlements in Kampala in 2014. A GIS data set from the survey was obtained from the Municipality of Kampala. Williams, Marcello, and Klopp [40] studied the land use of informal settlements in Nairobi in 2010. The data were obtained from the World Bank website (www.datacatalog.worldbank.org/). The Master Plan for the Municipality of Maputo (PEUMM) from 2008 includes land use maps. The land use data in DWG format were obtained from The Faculty of Architecture and Spatial Planning, Eduardo Mondlane University. Land use for informal settlements was exported in DXF format and placed manually in QGIS. The administrative boundaries of the three municipalities comprising Dar es Salaam (today there are five municipalities), the five central districts of the Municipality of Kampala, the eight divisions of Nairobi City County, and the six mainland districts of the Municipality of Maputo were obtained from The United Nations Office for the Coordination of Humanitarian Affairs (OCHA) website (www.data.humdata.org). The off-shore island and sea areas were excluded from the Maputo data and the Lake Victoria area was excluded from the Kampala data. The respective data sets were placed in QGIS. The total area of each municipality, as well as the total area of informal land use, was processed for each city using the union and dissolve commands, and the areas were subsequently calculated in the attribute table using the field calculator and the $area command. Ideally, the study would have compared the informal urban land use to the formal urban land use. However, such data were not available and the informal urban land use was thus calculated based on the size of the administrative areas and assessed qualitatively. As the data originate from different sources and were recorded at different times, and as the size of the cities and administrative areas vary, direct quantitative comparison was unsuited. Accordingly, a qualitative assessment of the extent of the informal urban development compared to the size of the city, the total administrative area, and the time of the survey was applied and summarized in the context descriptions. More specifically, the continuity or fragmentation of the informal land use was assessed based on visual inspection, as continuous informal land use likely signifies a lack of government control of urban development, while fragmented enclaves of informal land use likely signify more government control of urban development. 3.2. Acquisition of High-Resolution Spatial Data and Computation of Indicators of Urban Form A centrally located informal settlement in each of the four cities was surveyed. The settlements were selected based on location, size, and urban fabric. In order to exclude fringe cases, areas larger than four hectares (40,000 m2 ) were surveyed. Centrally located settlements were selected in each context in order to minimize the significance of distance to the CBD as a primary driver of the differences in urban form. All of the surveyed areas have unplanned organic urban fabrics and none include major public spaces, large institutions, or industry. Accordingly, the settlements have relatively homogenous urban fabrics relevant for comparison. The settlements were demarcated based on natural boundaries or major roads. These were not included in the data in order to avoid distorting the results. High-resolution orthophotos were produced by mapping the four settlements using an unmanned aerial vehicle (drone) for systematic collection of high-resolution photometric aerial data. The photometric data (aerial photos) were subsequently processed using Pix4D photogrammetry software to generate high-resolution geo-referenced orthophotos, digital surface models (DSM), and digital 3D models of each settlement. Such methods have previously been used by Kurczynski et al. [41]. The public space of each settlement was mapped by walking along the boundaries of every block with a handheld GPS device (smart phone) while using the SW maps application for tracing the movement. The GPS traces were exported in KMZ format and the orthophotos were exported in geo TIFF format. These were placed and automatically scaled in QGIS and exported in DXF format. The DXF file was opened in AutoCAD and layers for buildings, blocks, and the street network were created. All building boundaries were traced manually based on the orthophotos. Multi-story buildings were identified using the DSMs and the 3D models in Pix4D and separate layers were created for each floor. The perimeter for each story was traced manually and placed on the corresponding layer. The street network was traced manually based on the GPS trace and blocks were subsequently traced based on

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the orthophoto and street network. The total area of all floors, blocks, and the entire case study area was extracted from the properties bar by using the region and union commands. The number of blocks was extracted from the properties bar. The total length of the street network, block perimeter, and building perimeters was extracted using the Total Length (TL) plugin. The total public space area was calculated by extracting the total blocks area from the total case study area. Floor area ratio (FAR), public space ratio (PSR), ground space index (GSI), surface area to volume ratio (SAVR), average block size (AVB), and average street width (ASW) were calculated based on these data. Six urban form metrics were extracted from the spatial data. Five were used in previous studies, while one was developed in order to provide information on access conditions, which is a particular issue in many informal settlements. The indicators and method of computation are described next. •

• •

•

Floor area ratio (FAR): the total floor area divided by the total sample area. The metric highlights the intensity of the built environment [42]. FAR is usually calculated based on the total private space rather than the total area. However, in order to avoid distorting the FAR results by variations in the share of public space, the FAR was instead calculated using the total area. Public space ratio (PSR): the total public space divided by the total sample area. The metric highlights the level of public space [43]. Ground space index (GSI) also known as building coverage: the total building footprint divided by the total sample area. The metric highlights the level of the open space [42]. GSI is usually calculated based on the total private space rather than the total area. However, in order to avoid distorting the GSI results by variations in the share of public space, the GSI was instead calculated using the total area. Average block size: the total private area divided by the number of blocks. A block is private space surrounded by public space. The metric highlights the scale of the urban fabric [42]. Surface area to volume ratio: the total building surface area divided by the volume of all buildings. The surface area was calculated by summing the perimeter length of all buildings multiplied by the height of each floor (three meters) and adding to the total building footprint area multiplied by two. The volume was calculated by summing the total area of each floor multiplied by the height of each floor (three meters). As the height of the buildings occur on both sides of the fraction, the imprecise three-meter floor height assessment is largely negated. The metric highlights the compactness of the built environment [44]. Average public space width: the total area of the public space divided by the total length of the street network. The metric highlights the access conditions. The metric has not been used in previous studies, but was found to be relevant for assessing inadequate access conditions.

The survey of each settlement was carried out during the following periods of time: Hananasif, Dar es Salaam, Tanzania: January 2020; Katanga, Kampala, Uganda: May 2019; Kibera, Nairobi, Kenya: May 2019; and Maxaquene, Maputo, Mozambique: May 2019. 3.3. Field Interviews The field interviews were carried out alongside the physical surveys. Ten residents of each case study area were interviewed based on random selection, in different parts of the neighborhoods. This entailed a fairly even distribution of gender and relative socioeconomic diversity among the interviewees within each context. The interviews inquired regarding household access to water and sanitation, household size, dwelling size, whether the respondent was a tenant or land holder, and monthly cost of rent. As such, the questions included indicators of livelihood as well as three of five of the UN defined indicators of slums (overcrowding and inadequate access to water and sanitation) [45]. The number of people per room was calculated by dividing household size by household number of rooms. The responses from tenants and land holders showed significant variations and responses from each group are thus shown separately in the Results section. Due to the limited sample size,

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a literature review on household conditions in the respective contexts was carried out and relevant studies are cited in the Results section. 4. Results This section includes the results of the field interviews, the computed high-resolution spatial data of the case study areas, and context descriptions based on field observations and qualitative assessment of the land use data. 4.1. Context This context description is based on analysis of informal urban land use data in each of the urban administrative areas and a qualitative assessment of the urban form of each of the detailed case study areas. This section provides a brief assessment of the informal land use in each city, and a brief description of each of the surveyed settlements based on field observations and previous studies of the sample areas. These descriptions are subsequently used to contextualize the discussion. Dar es Salaam has approximately 6.70 million inhabitants and is the largest city in Tanzania and East Africa [46]. The city has one administrative body but consists of five municipalities [47]. The city is characterized by large continuous areas of informal urban development, stretching approximately 30 km into the land. The total informal land mass covered 10.36% of the total area of the city in 2002. However, the administrative area of the city is by far the largest and the sourced data are the earliest of the four cities. The informal areas have likely increased significantly since the sourced survey was carried out as peripheral areas of the administrative area of the city were largely undeveloped at the time. Accordingly, it is assessed that the authorities in the city exercise limited control of the land markets and informal settlements are de facto allowed to proliferate despite the extra-legal status. Informal settlements thus likely cover much larger areas and the share of informal areas in the city is thus likely significantly higher today compared to the time of the survey. Hananasif is one of the most centrally located settlements, at approximately 3 km from the CBD of Dar es Salaam. The settlement is characterized by single-story detached housing units and relatively wide streets, allowing access for cars. Kampala has approximately 3.29 million inhabitants and is the largest city and the capital of Uganda [48]. The Kampala Capital City Authority (KCCA) administers the five divisions of the city [49]. The city is characterized by fragmented enclaves of informal settlements. This indicates that authorities exercise some control of the land market. Informal settlements covered 13.74% of the five central districts of the city in 2014. However, the administrative area of KCCA is the smallest of the four examined cities and the majority of the land use was urban. Accordingly, informal settlements take up relatively limited space compared to the formal urban areas. Katanga is one of the most centrally located informal settlements in Kampala, at approximately 2 km from the CBD. Katanga is located next to the main hospital in the city and the settlement is surrounded by formal urban areas. The urban fabric of Katanga is mostly characterized by single-story dense clusters of buildings and small blocks. Nairobi has approximately 4.74 million inhabitants and is the largest city and the capital of Kenya [50]. The Nairobi City Council has eight administrative divisions [51]. The city is characterized by informal urban development limited to small fragmented enclaves. Informal settlements covered only 1.10% of the total area of the administrative area of the Nairobi City Council. While the city shows by far the smallest share of informal land of the four examined cities, it is important to note that Nairobi National Park is included in the administrative area and thus distorts the data towards a lower share of informal land use. Nevertheless, the data indicate that the authorities exercise more strict control of the land markets compared to the other three cities. This is corroborated by a previous study finding that authorities adopt policies of evicting residents of informal settlements in Nairobi [37]. Kibera is located 5 km southwest of the CBD. The settlement is characterized by large-scale one-, two-, and three-story buildings, large blocks, and limited public space. The large-scale buildings indicate large plot sizes and large-scale landowners supplying low-cost rental housing for the residents.

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Maputo has approximately 2.81 million inhabitants and is the largest city and the capital of Mozambique [52]. The city consists of seven administrative districts [53]. The city is characterized by widespread continuous informal land use. Informal settlements covered 29.45% of the administrative area of the Municipality of Maputo in 2008, excluding the off-shore islands. However, a bridge connecting the urban center to the southern district of Katembe has been constructed since the time of the survey, thus incentivizing urban development in the least developed main land part of the administrative area. Accordingly, the share of informal urban land use is likely higher today. This indicates that the city authorities exercise limited control of the land markets and informal settlements are de facto allowed to proliferate despite the extra-legal status. This is corroborated by a previous study which found that governments have granted some property rights protecting the residents of informal settlements in Maputo [38]. Maxaquene A is located approximately 3 km from the CBD of Maputo. The urban fabric of Maxaquene is characterized by single-story detached households, open private spaces, and large blocks. These conditions indicate large plot sizes. 4.2. Field Interviews and Literature Review on Household Conditions The field interviews are summarized and presented in Tables 1 and 2. The complete field interviews are available in Appendix A Figure A1. The interview data show large variations in tenure types, dwelling sizes, household sizes, and people per room, as well as levels of household access to water and sanitation, across the case study areas. The data show that tenants have significantly lower levels of access to water and sanitation and have almost exclusively single-room dwellings, while homeowner dwelling sizes average 4.48 rooms across the sample areas. Land holder household size averages more than double that of tenants and tenant households have almost twice as many people per room. These tendencies are reflected across the sample areas. Accordingly, sample areas with a higher share of tenants also have lower levels of access to water and sanitation, along with smaller average dwelling size, smaller average household size, and more widespread overcrowding. Although the sample size is too limited to generalize, the general levels (high, moderate, low) of the surveyed household conditions are largely consistent with previous studies found in the literature review presented in Table 3. Mapunda, Yu, and Chen [54] and Jenkins, Cumming, and Cairncross [55] report that the proportion of tenants in peri-urban Dar es Salaam is moderate. Okuruta and Charles [56] report that the proportion of tenants in informal settlements in Kampala is high. Gulyani and Talukdar [51] report that the proportion of tenants in informal settlements in Nairobi is high. Jenkins [36] reports that the proportion of tenants in informal settlements in Maputo is low. Accordingly, the tenancy data are consistent with previous studies. Mapunda et al. [54] report that the level of household access to water is moderate in peri-urban Dar es Salaam, while Kirama and Mayo [57] report that the level of household access to water is high in Dar es Salaam. Katukiza et al. [58] report that the level of household access to water in peri-urban Kampala is low. Gulyani, Bassett, and Talukdar [59] report that the level of household access to water in informal settlements in Nairobi is low. Forjaz et al. [60] report that the level of household access to water in Maputo is high. Accordingly, the household access to water data are consistent with previous studies. Jenkins et al. [55] report that nearly all low-income properties in Dar es Salaam have a sanitation facility. Okurut and Charles [56] and O’Keefe, Lüthi, Tumwebaze, and Tobias [61] report that the level of household access to sanitation in informal settlements in Kampala is low. O’Keefe et al. [61] report that the level of household access to sanitation in Kibera is low. Peal, Evans, Blackett, Hawkins, and Heymans [62] report that the vast majority of households in Maputo have onsite sanitation. Accordingly, household access to sanitation data are consistent with previous studies. The National Bureau of Statistics, Tanzania [63], reports that the level of overcrowding in Dar es Salaam is moderate. Mbiggo and Ssemwogerere [64] report that in Katanga, one-room dwellings are the most common dwelling type and that overcrowding is common. Marx, Stoker, and Suri [65] report that overcrowding is common in Kibera. Holcomb et al. [66] report that few households are crowded in low-income neighborhoods of Maputo. Accordingly, the household level of overcrowding data are consistent with previous studies. No relevant data for comparison across sample areas on cost

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of rent were found during the literature review. However, the data on the remaining socio-economic and livelihood indicators of household conditions were consistent with previous studies. Table 1. Interview data.

Tenants (%) Cost of rental household (USD/month) Dwelling size (rooms) Household size (people) People per room (people/rooms) Household access to water (%) Household access to sanitation (%) Tenants (%)

Hananasif

Katanga

Kibera

Maxaquene A

Average

40.00 17.20 4.40 9.40 2.13 60.00 100.00 40.00

90.00 27.12 1.10 4.00 3.64 0.00 0.00 90.00

90.00 40.15 1.30 4.90 3.77 0.00 30.00 90.00

0.00 4.40 6.30 1.43 90.00 100.00 0.00

55.00 28.16 2.80 6.15 2.74 37.50 57.50 55.00

Table 2. Tenant/homeowner differentiated interview data.

Tenant dwelling size (rooms) Homeowner dwelling size (rooms) Tenant household size (people) Homeowner household size (people) Tenant people per room (people/rooms) Homeowner people per room (people/rooms) Tenant access to sanitation (%) Homeowner access to sanitation (%) Tenant access to water (%) Homeowner access to water (%) Tenant access to electricity (%) Home owner access to electricity (%)

Hananasif

Katanga

Kibera

Maxaquene A

Average

1 6.67 2.25 14.17 2.25 2.13 100 100 50 66.67 75 100

1.11 1 3.33 10 3 10 0 0 0 0 88.89 100

1.22 2 5 4 4.09 2 22.22 100 0 0 88.89 100

4.4 6.3 1.43 100 90 90

1.11 3.52 3.53 8.62 3.11 3.89 40.74 75.00 16.67 39.17 84.26 97.50

Table 3. Household conditions based on the literature review.

Share of tenants Share of households with access to water Share of households with access to sanitation Share of households with overcrowding

Hananasif

Katanga

Kibera

Maxaquene A

Moderate [54,55] Moderate/high [54,57] High [55] Moderate [63]

High [56] Low [58] Low [56,61] High [64]

High [51] Low [59] Low [61] High [65]

Low [36] High [60] High [62] Low [66]

4.3. Urban Form of Case Study Areas The orthophotos and vectorized maps of the four case study areas are presented in Figure 2 and aerial photos of each of the four areas are presented in Figure 3. All indicators of urban form presented in Table 4 show variations across sample areas. The study found the highest FAR, GSI, and SAVR values in Kibera, while the lowest values of these three metrics were found in Maxaquene A. The study found the second highest FAR, GSI, and SAVR values in Katanga, while the second lowest values of these three metrics were found in Hananasif. Accordingly, the study found an identical order across all sample areas for the FAR, SAVR, and GSI indicators. The study found the lowest PSR in Maxaquene A and the highest PSR in Katanga, while the second lowest PSR was found in Kibera and the second highest PSR was found in Hananasif. The study found the highest ABS in Maxaquene A and the lowest in Katanga, while the second highest ABS was found in Kibera and the second lowest ABS was found in Hananasif. Accordingly, the study found a reverse identical order across all sample areas for the PSR and ABS indicators. The study found the lowest ASW in Maxaquene A and the highest ASW in Hananasif, while the second lowest ASW was found in Katanga and the second highest ASW was found in Kibera. The study found an identical order across all sample areas for all the built density indicators (FAR, GSI, and SAVR). The study found an identical order across all sample areas for two of three public space indicators (ABS and PSR). However, the study did not find a similar order of values across sample areas for the built density and public space indicators.

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Figure 2. Orthophotos and maps ofstudy caseareas. study areas. Figure 2. Orthophotos andvectorized vectorized maps of case Table 4. Indicators of urban form for the four surveyed areas.

FAR, Floor Area Ratio PSR, Public Space Ratio GSI, Ground Space Index AVB, Average Block Size (m2 ) SAVR, Surface Area to Volume Ratio ASW, Average Street Width (m)

Hananasif

Katanga

Kibera

Maxaquene

0.53 0.19 0.53 1187 0.80 3.92

0.65 0.22 0.63 329 0.79 2.06

0.75 0.10 0.71 2262 0.69 2.52

0.47 0.07 0.47 2812 0.89 1.99

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(a)

(b)

(c)

(d)

Figure 3. Aerial views of case study areas: (a) Hananasif, Dar es Salaam, Tanzania; (b) Katanga, AerialKampala, viewsUganda; of case studyNairobi, areas: (a)and Hananasif, es Salaam, Tanzania; (c) Kibera, Kenya; (d) Maxaquene Dar A, Maputo, Mozambique.

Figure 3. (b) Katanga, Kampala, Uganda; (c) Kibera, Nairobi, Kenya; and (d) Maxaquene A, Maputo, Mozambique. Table 4. Indicators of urban form for the four surveyed areas.

5. Discussion

Hananasif Katanga Kibera Maxaquene FAR, Floor Area Ratio 0.53 0.65 0.75 0.47 Spaceof Ratio 0.22 it outlines 0.10 This section analyzesPSR, thePublic results the study.0.19 Secondly, a0.07 provisional hypothesis of GSI, Ground Space Index 0.53 0.63 0.71 0.47 the mechanisms partiallyAVB, determining the informal urban development. Finally, it presents a number 2 Average Block Size (m ) 1187 329 2262 2812 SAVR, Surface Areaon to Volume Ratio 0.80the study. 0.79 0.69hypothesis, 0.89 of policy recommendations based the findings of The as well as the policy ASW, Average Street Width (m) 3.92 2.06 2.52 1.99

recommendations, are informed by the described urban economic theories in the introduction as well 5. Discussionof the study. as the empirical findings This section analyzes the results of the study. Secondly, it outlines a provisional hypothesis of the mechanisms partially determining the informal urban development. Finally, it presents a number 5.1. Analysis of Results

of policy recommendations based on the findings of the study. The hypothesis, as well as the policy

recommendations, is informed by the described urban economic theories in the introduction as well The study found large variations in the informal land use across the four examined cities and as the empirical findings of the study. thereby documents that the spatial extent of the informal urban development in major East African 5.1. Analysis of Results cities is characterized by significant variations. The study found variations within all seven indicators The study found large variations in the informal land use across the four examined cities and of urban form and thereby thatofcentrally unplanned in major thereby revealsdocuments that the spatial extent the informallocated urban development in majorinformal East African settlements cities is characterized by significant The study foundby variations within all seven indicators of characteristics. East African cities are not uniform, butvariations. are characterized a wide spectrum of spatial urban form and thereby reveals that centrally located unplanned informal settlements in major East The study found African large cities variations in household conditions and share of tenants across the sample areas. are not uniform, but are characterized by a wide spectrum of spatial characteristics. The study foundand large variations household conditions and share settlements of tenants across the Accordingly, livelihood tenure in conditions in informal in sample majorareas. East African cities vary significantly. In relation to the informal urban land use data, the fragmented and limited informal urban land use observed in Kampala and Nairobi, as well as the continuous informal urban land use observed in Dar es Salaam and Maputo, suggests that government attitudes towards informal urban development differ significantly between different contexts, as reported in previous studies such as Jenkins [67] and Talukdar [37]. This is underscored by the 1.10% share of informal urban land use within the administrative area of Nairobi City Council and the 29.45% share of informal land use in the main land administrative area of Maputo Municipality. Accordingly, the study suggests that practices of authorities towards informal urban development have significant implications for informal urban land use. In relation to the public space indicators of urban form, the study found an identical order across all sample areas for the PSR and ABS indicators. The study found a higher share of public space in areas with smaller average block sizes and a lower share of public space in areas with larger average sizes. Accordingly, the study suggests that the share of public space in unplanned informal settlements is linked to the average block size. The study found both the lowest built densities (FAR, GSI, and SAVR) and the lowest PSR in Maxaquene A. Accordingly, the study suggests no link between low

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levels of public space and high built densities or a lack of free private space. The study did not find any similar ordering of the ASW indicator and the other indicators across the sample areas. Accordingly, the study suggests access conditions are not linked to the urban layout or built densities in unplanned informal settlements. As smaller blocks require more street network length per area to provide access, elementary geometry may account for parts of the link between PSR and ABS. The study thus suggests that the street layout is significant for the share of public space in informal settlements. As block sizes are determined by the street layout, the early processes of the formation of an informal settlement are essential for the development of public space. However, as ASW is not linked to PSR or ABS, the access conditions are likely linked to the subsequent governance of the informal settlements and, particularly, to what extent street encroachment is accepted by local governance structures. Accordingly, the local governance structures are likely fundamental for the development of public space in informal settlements at the time of the formation, as well as during the subsequent ongoing process of development. The study found the lowest ASW values in Katanga and Maxaquene A. These values (roughly two meters) may approximate a minimum of access conditions for both the human body and internal transportation of goods in the settlements. The study found that the share of public space alone provides inadequate information on the access conditions in informal settlements, as settlements with small blocks can have a relatively high PSR and relatively low ASW. This insight may have implications for the urban planning of so-called “slum-upgrade” projects. In relation to the built density, the study found identical ordering across the sample areas for the FAR, GSI, and FAR indicators. Notably, a similar ordering was found across the sample areas for the informal land use data and household data. The study found the most fragmented informal urban land use in Kampala and Nairobi and the informal urban development is likely more restricted in these cities. The study found more continuous informal urban land use in Dar es Salaam, while the most continuous informal urban land use was found in Maputo. Accordingly, informal urban development is likely less restricted in these cities. The study found higher built densities in the Kampala and Nairobi case study areas, while moderate built densities were found in the Dar es Salaam case study area and lower built densities were found in the Maputo case study area. Similarly, the interview survey and literature review found a high share of tenants and higher levels of compromised livelihood in Kampala and Nairobi, a moderate share of tenants and moderate levels of compromised livelihood in Dar es Salaam, and a low share of tenants and low level of compromised livelihood in Maputo. All four countries included in this study have high population growth rates, low national GDP per capita, and high rates of urbanization [46,48,50,52]. All four cities have large populations and urban poor majorities financially excluded from the formal housing market [3]. Accordingly, the demand for informal land in all five cities is likely high. As all four case study areas are centrally located, they represent some of the densest informal settlements within the respective contexts. Kibera is the least centrally located case and has the highest built density. Accordingly, centrality cannot account for the variations in the built density data. Hananasif is located in the largest city and the second lowest built densities were found in this sample area. Accordingly, the total urban population size cannot account for the variations in the built density data. Maputo is located in the country with the lowest GDP per capita of the four examined cities and the lowest levels of compromised livelihood were found in this sample area. Accordingly, GDP per capita cannot account for the variations in the household condition data. Geographic factors, such as mountains, lakes, and the sea, may influence the total land mass available for urban development in any given city and thereby also influence the size of informal land mass. The center of Maputo is located at the tip of a peninsula and large parts of the municipal land mass were inaccessible at the time of the survey due to it being conducted before the newly constructed bridge which provides better access to Katembe (the area south of the bay). The urban development in Nairobi is not conditioned by geographic constraints to the same extent. Consequently, geographic factors likely curb informal urban development in Maputo to a higher extent than Nairobi, yet informal urban development is much more widespread in Maputo. Accordingly, geographic factors cannot account for the variations in the informal urban land use. As demonstrated,

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factors such as neighborhood centrality, total urban population size, GDP per capita, and geography cannot account for the variations in the data. This study argues that the level of government control of the land market is the primary driver of the differences in the informal land use data, the urban density data, and the household condition data across the sample areas. This is explained in further detail in the following section. 5.2. A Hypothesis on Informal Land Supply, Livelihood, and Urban Form in Cities in Sub-Saharan Africa This section outlines a provisional hypothesis for understanding informal urban development in cities characterized by high population growth rates and urban majorities financially excluded from the formal housing markets. More specifically, the hypothesis explains how government practices towards informal urban development partially determine the urban form and the livelihood in informal settlements. The hypothesis consists of three hierarchical layers. First, the governance practice partially determines the informal land supply. Second, market mechanisms partially determine the price of informal land. Third, the price of informal land partially determines household conditions and development of urban form. The hypothesis is presented in Figure 4. This hypothesis is limited to cities with large populations financially excluded from the formal housing market and limited capacity to administer urban development. However, such conditions are widespread in large cities throughout sub-Saharan Africa. These conditions are not necessarily reflective of particular context-specific cultural practices and more likely linked to general economic and demographic developments. Accordingly, cities in different cultural settings characterized by large populations financially excluded from the formal housing market and limited state capacity to administer urban growth will likely develop within similar structural conditions. Hence, urban form and household conditions will likely also be partially determined by informal land supply in such settings. Accordingly, cities in other parts of the Global South characterized by extensive urban growth, urban poor majorities excluded from the formal housing market, and limited state capacity to administer urban growth will likely develop according to the hypothesis. The results of the study demonstrate large variations in the informal land use at municipal administrative levels, reflecting large variations in government practices towards informal urban development. Gulyani et al. [26] argued that informal land markets work similarly to formal land markets. Accordingly, previously outlined land use models may explain variations in built densities and household conditions presented in this study. The formal–informal price gap reflects a spatial equilibrium, in which the lower land prices in informal settlements are offset by a lack of property rights and consequent lack of tenure security. As tenure security represents an important amenity, the formal–informal market value of land differs significantly. This price difference excludes the urban poor from owning formal land. If simple supply and demand mechanisms partially determine the cost of informal land, government attitudes and practices towards informal urban development influence the informal land supply and thereby land prices. More specifically, government restriction of informal urban development will decrease informal land supply and thereby increase the competition in the informal land market, resulting in increased costs of land and accommodation in the informal market. Conversely, government acquiescence to the proliferation of informal urban development will increase informal land supply, and thereby decrease competition in the informal land market, resulting in decreased price of land and accommodation in the informal market. Mottelson and Venerandi [68] first proposed this mechanism explaining variations in livelihood and built densities in informal settlements. Angel [69] provided a similar argument, namely that greenbelt policies increase costs of affordable housing due to containment of urban expansion and consequent decreased land supply, resulting in increased competition and higher costs of accommodation. Consequently, government restriction of informal urban development through forced evictions decreases the informal land supply and thus leads to increased costs of accommodation. Government restriction of informal urban development and consequent increasing costs of informal land further exclude the least wealthy parts of the population from holding land and thereby lead to an increased share of tenants in the population.

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This mechanism is underpinned by the fragmented and limited informal urban land use, the high share of tenants, and the high cost of accommodation seen in Nairobi and Kampala, and conversely by the continuous informal urban land use, lower share of tenants, and lower costs of accommodation seen in Dar es Salaam and Maputo. Increased financial exclusion from holding informal land leads to an increased share of tenants. Accordingly, the increased costs of land caused by decreased informal land supply may account for the high share of tenants observed in Kampala and Nairobi, the moderate share of tenants in Dar es Salaam, and the low share of tenants in Maputo. As residents of informal settlements typically have limited economic resources and cannot obtain loans in banks as their properties are extra-legal, the investment capacity for construction is largely limited. Households in informal settlements typically develop incrementally when economic resources for expansion are available [70]. As overcrowding is common in informal settlements, expansion of households is typically desired. However, built densification is largely constrained by the household economy. The population densities in the informal urban areas are an outcome of the size of the population financially excluded from the formal housing market and the total area of the informal urban land use. Limited informal urban land use and large populations financially excluded from the formal housing market thus result in high population densities. This, in turn, is linked with a high share of tenants. The income generated by tenants provides increased investment capacities for landlords and is likely a contributing factor to the higher built densities seen in informal urban areas with a high share of tenants. Furthermore, the economic incentives for landlords to optimize the use of space may partially account for the development of more compact urban form as seen in the case study areas with a higher share of tenants. Finally, the higher population densities in informal settlements in cities with limited informal land supply and large populations financially excluded from the formal housing may provide an increased accumulative collective investment capacity of high-density populations and thereby contribute to the higher built densities.

Figure 4. Graphic representation of the Hypothesis on Informal Land Supply, Livelihood, and Urban Form in Cities in sub-Saharan Africa: 1: governance practice, 2: market mechanisms, and 3: household conditions and urban form.

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Glaeser and Gottlieb [23] argued that increasing house prices do not naturally represent an increase in national wealth since the values have been offset by an increase in cost of securing a basic necessity. Accordingly, increased competition in the informal land market will likely result in higher rents, leading to fewer household resources for other investments. Furthermore, the insecure investment conditions in informal rental housing in cities where authorities enforce evictions of informal settlements may result in a price premium paid by users due to the risk of lost investments further contributing to higher costs of rent in cities where authorities adopt more strict practices towards informal urban development. Investments in infrastructure largely depend on private funding as public investments in informal settlements are limited. Infrastructure also represents valuable amenities leading to increased market value according to the spatial equilibrium theory. Accordingly, access to infrastructure is linked to higher costs of rent. Restriction of informal land supply in cities with high population growth and large populations excluded from the formal housing market may lead to higher costs of accommodation. Accordingly, the level of informal land supply may directly affect the level of access to basic infrastructure, as low levels of informal land supply will lead to increased land prices and higher rent, which thereby reduce the economic leeway for covering costs of infrastructure. This may, in turn, lead to fewer household resources for investments in basic infrastructure such as durable housing and sufficient living space, as well as adequate water and sanitation. This mechanism is underpinned by the study as the examined cities with limited informal urban land use also have higher proportions of tenants and overcrowding, as well as lower levels of access to water and sanitation, while the cities with more informal urban land use have lower levels of tenants and overcrowding and higher proportions of access to water and sanitation. 5.3. Policy Responses This paper argues that restriction on informal urban development in major cities in sub-Saharan Africa results in compromised livelihood for large parts of the populations. Accordingly, the policy implications may be significant if decision-makers consider improved livelihood a political goal. Complying with the building code and following the formal procedures of land management lead to increased costs for the land users. Furthermore, the administrative capacity of the public sectors to process the legal framework for formal urban development is inadequate in most major cities in the region. Accordingly, there is a need to decrease the costs of complying with regulations for the users, as well as a need to decrease the bureaucratic workload of urban land management for authorities. Some countries recognize that the residents were not able to comply with regulations or that the limited administrative capacity of the state did not provide viable alternatives to informal housing during the time of establishment of the informal settlements [36]. Consequently, these countries already grant some land rights to residents of informal settlements. This includes some protection from uncompensated forced evictions and a legal path towards formalization. A new category of tenure may be developed in order to provide rights to informal land holders and provide a higher degree of tenure security. This informal landholder title may be governed with less costly requirements for spatial surveys and less strict application of the building code. More specifically, urban development may be guided with simple zoning plans permitting auto-construction within certain spatial frameworks of plots. This may include standardized setbacks from access routes and maximum building heights. Such zoning could be administered by the local authorities in the informal settlements without involvement of high-salary technical professionals. The study demonstrates that local authorities, such as in Hananasif, can facilitate development of a desirable urban form with adequate access conditions and public space. Accordingly, such local authorities may be given additional administrative power, financial resources for investments in infrastructure, and technical training in administering urban development locally. Such policy proposals would target existing informal settlements in order to address issues with illegal construction, insecure tenure, and inadequate infrastructure. In order to address high costs of accommodation, governments may consider expanding the informal land supply by designating new areas for informal construction. This could be pioneered

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through state-financed allocation of small plots with leasehold titles on government-owned land, with allocation of sufficient street space, common water and sanitation units, and local guidance for auto-construction without strict enforcement of the building code. The local administration of these areas may receive capacity building in urban management to provide general guidelines for autoconstruction according to basic zoning, similarly to the ones described in the previous paragraph. Appropriate solutions for such pilot areas may include minimal plot sizes corresponding to an apartment, on which the citizens construct their houses guided by the local administration according to the zoning. Common bathrooms, showers, and water posts may be public-funded to provide infrastructure for those who cannot afford the solutions provided by the market. The study argues that such initiative would provide viable housing options for low-income populations and thereby decrease the competition in the informal land market, resulting in lower costs of accommodation. This may, in turn, free household resources for investments in basic infrastructure and thereby improve livelihood. Technological development has brought low-cost survey solutions with drones and community mapping with smart phones. Innovation in this field may advance affordable land management solutions utilizing drones, apps, and smartphones to provide new forms of geo-surveys of landmarks, built structures, plot boundaries, and public spaces. This could include automatically generated guidance based on inputs given to an app according to basic zoning requirements for autoconstruction described previously in this section. Such systems may be developed and tried as tools to address the negative consequences of a lack of urban regulation without the added costs for formalizing land and provide a path towards formalizing land ownership. These recommendations relate to general discussions on the applicability of Global North-based urban planning paradigms in the Global South. The standards of administration, governance, and urban planning practice from the North were arguably developed corresponding to societies with more economic resources. The human capital and economic costs of such standards arguably do not correspond to the current conditions in much of the Global South and discussions on appropriate standards corresponding to the local conditions are important. 6. Conclusions The study found large variations in informal urban land use across the four examined cites. Accordingly, attitudes and practices towards informal urban development likely vary among authorities across the region. The study found that centrally located settlements in the four examined cities have diverse urban form characteristics. More specifically, the study found diverse built densities and public space conditions. The study suggested that the public space ratio in informal settlements is linked to average block size. The study found that built densities do not influence the public space ratio and this is largely determined through the governance of the early formation of the settlement when blocks are established and the subsequent governance determining the level of street encroachment. The study found higher built densities in the case study areas located in the examined cities characterized by limited informal land use. The study also found a high share of tenants, more widespread overcrowding, and lower levels of access to water and sanitation in the examined cities with limited informal urban land use. Based on these findings, the study proposed a novel hypothesis on informal urban development in cities in sub-Saharan Africa characterized by majorities financially excluded from the formal housing market. The hypothesis is structured in three hierarchical layers. First, the governance practice partially determines the informal land supply. Second, market mechanisms partially determine the price of informal land. Third, the price of informal land partially determines household conditions and development of urban form. The hypothesis is underpinned by empirical findings showing consistency between the theoretical concepts and data. However, the relation between the property prices, location, and urban density of informal settlements in sub-Saharan Africa remains under-researched [27]. Accordingly, further studies are needed to corroborate the hypothesis.

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The paper argues that informal urban development proliferates when the administrative capacity of the state is limited and large parts of the populations have too limited resources to comply with regulations. The paper argues that enforcement of the law through eviction of the informal settlements leads to worse living conditions for the population financially excluded from the formal market. However, this does not mean that public policy should enhance the proliferation of informal urban development. Contrarily, the paper argues that the requirements for what is considered formal should be changed so that they require fewer resources in public administration and are less costly for the general population. Funding: This research was funded by The Danish Council of Independent Research (ID: 7023-00007B) and the Royal Danish Academy. Acknowledgments: I would like to thank the municipality and local authorities in the five settlements studied in this paper for permitting the spatial surveys as well as the members of the communities of each settlement who participated in the field interviews. Finally, I would like to thank the following residents who facilitated the field work: Mario Mugano Xikumbane, Ali Muhammed Muhina, Ally Hassan Ally, Daniel Futwax, John Saturday Bwambale, David Esenga, Kyeyune Daniel, Vero Razafinirina, Ravaonirina Andrine, Rasoanirina Zoeline, and Rabevaza Selestin. Conflicts of Interest: The author declares no conflict of interest. Land 2020, 9, x FOR PEER REVIEW

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Appendix A Appendix A

Figure A1. Full interview data. The interviewees are numbered horizontally to the right of the

Figure A1. Full interview data. The interviewees are numbered horizontally to the right of the neighborhood name with responses for each question underneath. The responses to the binary neighborhood withare responses question (yes/no)name questions assigned 1for for each yes and 0 for no. underneath. The responses to the binary (yes/no) questions are assigned 1 for yes and 0 for no. References 1.

2. 3.

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Juxtapositions A caddie carries the golf clubs for a neatly dressed man wearing white gloves adjacent to piles of garbage, scrap material structures, and children in tattered clothes. Kibera is colloquially known as the largest slum in Africa and a mere concrete wall separates the vast misfortune in the settlement from a freshly trimmed green golf pitch. The absurd juxtaposition is a material manifestation of a nonsensical unequal distribution of resources.

On the Impact of Urban Planning of Informal Settlements in Sub-Saharan Africa Johan Mottelson Pending publication Abstract In Sub-Saharan Africa, the urban majorities reside in informal settlements. Lack of knowledge on the spatial and socioeconomic impact of urban planning on informal settlements compromises the basis for policy and decision making. This study compares the urban form of three centrally located unplanned informal settlements with three adjacent planned informal settlements in Maputo, Mozambique in order to assess the long-term impact of urban planning on the urban form of informal settlements. The study includes field interviews on household conditions in each of the six cases in order to assess the relationship between the structure of the urban fabric and socio-economic conditions in informal settlements. The study found higher built densities, higher public space ratio, higher average street width, and a higher proportion of tenants in all three planned areas compared to the three unplanned areas. Accordingly, the study suggests that urban planning has a significant long-term impact on the urban form of informal settlements despite the lack of state control of the urban development. The study argues that planned urban areas are seen as more desirable which offsets the market value of land in these areas and leads to shifts in the socio-economic conditions of the residents. The study argues that this dynamic partially accounts for the higher proportion of tenants and the higher built densities found in the planned case study areas. The study argues that smaller plot sizes and more simple plot geometries may further explain the higher built densities in the planned case study areas. The study found urban form variations within the three planned areas which are suggested local governance practices account for. The study argues that urban management capacities should be strengthened in the local neighbourhood administrative systems in order to counter issues with street encroachment and thereby enhance the feasibility of future infrastructure investments. Keywords: urban form, urban morphology, urban planning, informal settlements, Sub-Saharan Africa, Maputo, Mozambique Introduction Most of the ongoing extensive urban growth in East Africa occurs beyond the limits of state control and regulatory systems (UN-Habitat, 2020). The urban majority in the region resides in informal settlements typified by construction without formal permits and lack of formal land titles (UNHabitat, 2020; OECD, 2008). The proliferation of informal urban development will likely continue in the coming decades due to high rates of urbanisation, high fertility rates, poor urban majorities, and limited state capacity to administer the urban growth (Jenkins & Mottelson, 2020). Lack of knowledge on the formation and development of informal settlements limits the capacity to develop effective policy and urban planning in Sub-Saharan Africa (UN-Habitat, 2013). However, limited studies have investigated the urban

form of informal settlements despite that spatial factors and urban form indicators such as inadequate access conditions, inefficient use of space, high level of building coverage, and limited public space are linked to common urban deficiencies in informal settlements (Mottelson & Venerandi, 2020). Inadequate urban planning compromises sustainable development in many urban centres in sub-Saharan Africa (Hove et al., 2013). However, the long-term spatial impact of urban planning in informal settlements remains understudied. This study provides a comparative analysis of the urban form of adjacent planned and unplanned informal settlements in Maputo, Mozambique in order to enhance the knowledge on the long-term spatial impact of urban planning on informal settlements and thereby improve the basis for assessing the impact of urban planning in contexts characterized by informal urban development. Urban Morphology Urban morphology is the study of the form of human settlements with the aim of describing their spatial structures and understanding the process of their development (Moudon, 1997). Muratori (1959) argues that the structure of a city is understood historically focusing on the diachronic processes of transformations through the ‘operative history’. Furthermore, Muratori introduces a classification of building typology and adjacent open spaces as the basis of understanding of the development of the city (Moudon, 1994). Conzen (1960) defines a town plan as a topographical arrangement of street-systems comprised of streets, street-blocks comprised of plots, and block-plans comprised of buildings. In addition, Conzen introduces a methodology for town-plan analysis focusing on the development of the formative processes of the pattern of streets, the pattern of building forms, and pattern of land use in order to gain an understanding of the socio-economic formative conditions of the development of the city. Hillier and Hanson (1984) use mathematical representation and analysis of street networks, which was later developed into a variety of algorithms and software applications for the analysis of urban form, such as Space Syntax (Hillier, 2007). Multiple methods for street network configuration analysis have emerged, such as node degree centrality, closeness, and betweenness (Porta et al., 2010). Node centrality degree measures the number of nodes that each node is connected to (the number of streets leading into each intersection) and measures the involvement of the node in the network (Opsahl et al., 2010). Closeness (integration in Space Syntax) is a measure of the number of transitions required from one street to reach all other streets in the network using the shortest paths (Vaughan, 2007). Betweenness is a measure of the number of times a node (street intersection) acts as a bridge along the shortest path between two other nodes (Porta et al., 2006). Correlation between street network configuration and human behaviour, such as frequency of crime, the intensity of commercial activities, and movement of people have been documented through the use of these applications (Scoppa & Peponis, 2015; Kim & Hipp, 2019; Hajrasouliha & Yin, 2015). However, configurational analysis does not account for other morphological aspects such as built-mass density thus limiting the scope of such methods

(Ratti, 2004). A number of studies have documented the correlation between urban density measures and energy consumption, mobility, and costs of infrastructure provision thus underpinning the importance of such measures (Álvarez et al., 2014; Horner, 2013; Trepci et al., 2020). Other studies have documented correlation between urban tree canopy cover and urban microclimate, education levels, and median household income in urban areas (Elmes et al., 2017; Heynen & Lindsey, 2003; Schwarz et al., 2015). Gehl (2011) documents that residents of low-rise high-density areas are acquainted with more of their neighbors than residents of tower blocks thus suggesting a correlation between building typologies and the social conditions of urban areas. Rådberg (1996) introduces a quantitative multi indicator classification of urban types using land coverage, Floor Area Ratio (FAR), and building heights as indicators of urban form. Similarly, the Space Matrix treats density as a multivariable phenomenon, in a three-dimensional diagram, with the three fundamental indicators: intensity (FSI), compactness (GSI), and network density (N) on each axis (Berghauser Pont & Haupt, 2009). The increased availability of morphological data and computational power have enabled more complex quantitative forms of analysis and the emergence of urban morphometrics using systematic measurement of multiple configurational and urban density measures as morphological indicators (Dibble et al., 2019; Fleischmann, 2019). Studies using such methods have found a correlation between urban form and public health, energy consumption, and liveability of neighbourhoods (Marshall et al., 2014; Ratti et al., 2005; Venerandi, 2017). However, limited studies have investigated the urban morphology of informal settlements, particularly in the context of Sub-Saharan Africa. Hillier et al (2000) examine informal settlements in Santiago, Chile and suggest that spatial and locational factors drive the development and consolidation of informal settlements. The study suggests that edge oriented commercial activity and consequent inclusion in the wider local economy is determined by the levels of spatial integration within the surrounding urban fabric and is significant for consolidation of the built form of informal settlements. However, Hillier et al primarily focus on features of the street network, thus missing further aspects of the built environment. Smith & Jenkins (2015) examine the development of informal settlements in Huambo, Angola and suggest that the urban growth entails decreasing household sizes, plot subdivision, increasing provision of rental accommodation, and increasing density of land occupation by buildings. Mottelson and Venerandi (2020), examine the urban form of centrally located informal settlements in major cities in East Africa and find that these are characterized by diverse urban form features. Mottelson (2020b) examines urban densification in peri-urban Maputo (2007-2017) and finds increasing built densities and decreasing population densities in the centrally located settlements over the ten-year period. Dovey et al. (2020) trace the development of street networks and buildings in multiple informal settlements, demonstrating the range of morphologies characterizing these areas. They analyse building types, plots, blocks, streets and lanes in order to highlight how habitable land, affordable housing and

public space is produced in different contexts. Jenkins (2013) identifies four types of informal settlements in Maputo, Mozambique. Namely, 1) Planned formal, 2) Unplanned informal, 3) Planned informal, 4) unplanned formal. The planned informal settlements include areas which have been planned by the local government, international agencies or by locally commissioned planners but are not recognized by the municipality as formally planned areas. Construction in these areas is thus extra-legal, as construction permits can only be formally issued in areas with approved urban plans and these urban areas have thus developed under limited formal governance of the state. Accordingly, these areas are informal settlements despite the planned structure of the urban fabrics. However, no studies have investigated the impact of urban planning on the development of the urban form of informal settlements. Accordingly, this lack of knowledge limits the capacity for impact assessment of urban planning projects and the basis for making policy decisions in this context. In order to reduce this knowledge gap, this study seeks to answer the following questions: what is the impact of urban planning on the development of the urban form of informal settlements? what is the impact of urban planning on the development of socio-economic conditions in informal settlements? This study analyses the urban form and household condition of three case study areas covering planned and unplanned adjacent informal settlements in order to answer these research questions. The study is based on analysis of high-resolution maps created with unmanned aerial vehicles (drones), handheld GPS-devices (smartphones) and photogrammetry software. The study includes field interviews on household conditions with residents of the surveyed areas in order to examine links between urban form and socio-economic conditions of informal settlements. Thereby, the study seeks to increase the knowledge of the spatial impact of urban planning in order to improve the basis for decision making. Methodology Three centrally located informal urban areas in Maputo were selected for the study. The areas are located in KaMaxakeni (District 3) in the Maxaquene (A, B, and D) and Polana Caniço A neighbourhoods. The selection criteria for the case study areas were based on the urban structure, the time of establishment, and the proximity to the city centre. Generally, the cases were selected based on overall similarity aside from the urban fabric and local administration conditions. More specifically, the case study areas include unplanned and planned adjacent informal settlements in different administrative areas characterized by similar distances to the city centre, similar times of establishment, and similar socio-economic conditions. Areas with adjacent planned and unplanned informal settlements were selected in order to provide a basis for comparison of the two types of urban fabric. Urban density is linked to transport costs to the city centre (Bertaud, 2018). Accordingly, adjacent cases were selected in order to reduce the influence of location factors for the development of the urban form of the case study areas. Informal settlements densify over

time (Mottelson, 2020b). Accordingly, cases established within a similar time frame were selected for the study in order to reduce the influence of temporal factors on the development of the urban form of the case study areas. Three cases were selected in order to examine differences between different administrative areas with similar location conditions. The urban areas were demarcated based on major roads forming the exterior boundaries. These roads were not included in the data in order to avoid distorting the results. High-resolution orthophotos were produced by mapping the three case study areas using an unmanned aerial vehicle (drone) for systematic collection of high resolution photometric aerial data. The photometric data (aerial photos) were subsequently processed using Pix4D photogrammetry software to generate high-resolution geo-referenced orthophotos, Digital Surface Models (DSM) and digital 3d models of each settlement. Such methods have previously been used by Kurczynski et al (2016). The public space of each settlement was mapped by walking along the boundaries of every block with a handheld GPSdevice (smartphone) while using the SW maps application for tracing the movement. The GPS traces were exported in KMZ format and the orthophotos were exported in geo TIFF format. These were placed and automatically scaled in QGIS and exported in DXF format. The DXF file was opened in AutoCAD and layers for buildings, blocks and street network were created. All building boundaries were traced manually based on the orthophotos. Multi-storey buildings were identified using the DSMs and the 3d models in Pix4D and separate layers were created for each floor. The perimeter of each storey was traced manually and placed on the corresponding layer. The street network was traced manually based on the GPS trace and blocks were subsequently traced based on the orthophoto and street network. The total area of all floors, blocks and the entire case study area were extracted from the properties bar by using the region and union commands. The number of blocks was extracted from the properties bar. The total length of the street network, block perimeter and the building perimeters were extracted using the Total Length (TL) plugin. The total public space area was calculated by extracting the total blocks area from the total case study area. Floor area ratio (FAR), public space ratio (PSR), ground space index (GSI), average block size (ABS), surface area to volume ratio (SAV), urban tree canopy cover (UTC), and average street width (ASW) were calculated based on these data. The urban form indicators and methods of computation are described below. ●

Floor area ratio (FAR): the total floor area divided by the total sample area. The metric highlights the density of the built environment (Berghauser Pont & Haupt, 2009). FAR is usually calculated based on the total private space rather than the total area. However, in order to avoid distorting the FAR

results by variations in the proportion of public space, the FAR was instead calculated using the total sample area. ●

Public space ratio (PSR): the total public space divided by the total sample area. The metric highlights the level of public space (Oliver-Solà et al., 2011).

●

Ground space index (GSI) also known as building coverage: the total building footprint divided by the total sample area. The metric highlights the level of open space (Berghauser Pont & Haupt, 2009). GSI is usually calculated based on the total private space rather than the total area. However, in order to avoid distorting the GSI results by variations in the proportion of public space, the GSI was instead calculated using the total area.

●

Average block size (ABS): the total private area divided by the number of blocks. A block consists of private space surrounded by public space. The metric highlights the scale of the urban fabric (Berghauser Pont & Haupt, 2009).

●

Surface area to volume ratio (SAV): the total building surface area divided by the volume of all buildings. The surface area was calculated by summing the perimeter length of all buildings multiplied by the height of each floor (three meters) and added with the total building footprint area multiplied by two. The volume was calculated by summing the total area of each floor multiplied by the height of each floor (three meters). As the height of the buildings occurs on both sides of the fraction, the imprecise threemeter floor height assessment is largely negated. The metric highlights the compactness of the built environment (Ratti et al., 2005).

●

Average street width (ASW): the total area of the public space divided by the total length of the street network. The metric highlights the level of access conditions (Mottelson, 2020a).

●

Urban tree canopy cover (UTC): the total ground area covered by the crowns of trees divided by the total sample area. The metric highlights the density of urban trees (Nowak et al., 1996).

The field interviews were carried out alongside the physical surveys. Sixty residents (ten of each sub-area) were interviewed based on random selection, in different parts of the sample areas. This entailed a fairly even distribution of gender and relative socioeconomic diversity among the interviewees within each context. The interviews inquired regarding household access to water and sanitation, household size, dwelling size, whether the respondent was a tenant or landholder, and the monthly cost of rent. As such, the questions included indicators of livelihood as well as three of five of the UN defined indicators of slums (overcrowding and inadequate access to water and sanitation) (UN-Habitat, 2003). The spatial surveys and the field interviews were carried out in June and July 2019. Context Mozambique is located in South-East Africa and is one of the poorest countries in the world (Jenkins, 2000a). Maputo is the capital of the country and the city is characterized by a formal urban centre surrounded by informal settlements to the West and North and the Maputo Bay to the East and South. The urban centre was established in 1781 by Portuguese colonialists, while the majority of the informal urban areas were established after independence in 1975. The urban development after independence was characterized by a large influx of rural population due to the ongoing civil war causing large numbers of refugees along with the abolishment of previous restrictions on the movement of people (Jenkins, 2000b). Maputo consists of 7 administrative districts. District 1 covers the formal city centre, districts 2-5 cover the informal urban areas to the North and West of the centre, while districts 6-7 cover the island of Inhaca and Katembe south of the bay, which was connected to the city centre via a new bridge in 2018. However, the continuous urban fabric of the greater Maputo metropolitan area includes the neighbouring Matola Municipality as well as Marracuene and Boane districts North and West of the Municipality of Maputo (Jenkins & Mottelson, 2020). The city is characterized by widespread continuous informal land-use indicating that the authorities exercise limited control of the land markets and informal settlements are de facto allowed to proliferate despite the extra-legal status (Mottelson, 2020a). Each of the districts has a district administration office (administração do distrito) facilitating contact between the neighbourhoods and the municipal administration. Each district is subdivided into a number of neighbourhoods (bairros) with a neighbourhood administration office (secretário de bairro). The neighbourhoods are subdivided into a number of blocks (quarteirão) typically 35-100 housing units, each of which has an appointed block leader (chefe de quarteirão) (Barros et al., 2014). Building permits can only be formally issued by the municipality on formally owned land in areas with approved

Road Municipal Boundary Sea, estuary & river Case study area 5

N 10 km

Figure 1: Overview of Maputo urban plans. Nevertheless, informal permits are issued by the local administration (district and neighbourhood), without legal basis and with no involvement of the higher levels of municipal administration. The local neighbourhood administrations thus carry out some form of governance of the development of the neighbourhoods despite the lack of formal mandate to do so (Andersen et al., 2015a, 2015b). However, as such practices are not established on the basis of the law, it is plausible that these practices differ between neighbourhoods with possible impact on the development of the urban form. The three case study areas are located in District 3 which were established during the influx of population subsequent to independence. The three planned case study areas are outcomes of the Urbanization Project of Maxaquene and Polana Caniço (1977–1979) where the population was relocated in order to implement the structural readjustment and consequent planned urban fabrics seen today (Pinsky, 1982). An overview of Maputo along with the location of the three case study areas are presented in Figure 1, an overview of the three case study areas is presented in Figure 2, and aerial photos of planned and unplanned sample areas are presented in Figure 3.

Private area Single-storey building Two-storey building Trees Unplanned area Planned area 200 m

400 m

Figure 2: Overview of case study areas

Figure 3: Aerial views of planned and unplanned case study areas.

FAR

PSR

UTC

ASW (m)

SAV

ABS (m2)

Maxaquene A, Planned

0,51

0,11

0,0593

3,00

2,00

2365

Maxaquene A, Unplanned

0,47

0,07

0,0521

1,98

1,78

2887

Maxaquene D, Planned

0,46

0,10

0,0971

3,17

1,88

3289

Maxaquene B, Unplanned

0,43

0,08

0,1334

2,42

1,77

3245

Polana Caniço A, Planned

0,48

0,11

0,1299

2,99

2,05

1598

Polana Caniço A, Unplanned

0,38

0,09

0,1909

2,89

1,79

3250

Planned areas average

0,49

0,11

0,0954

3,05

1,98

2417

Unplanned areas average

0,42

0,08

0,1255

2,43

1,78

3127

Table 1: Urban form data Dwelling size (rooms)

Household size (people)

People per room

Tenants (%)

Water (%)

Electricity (%)

Sanitation (%)

Maxaquene A, Planned

100

4,2

5,7

1,36

Maxaquene A, Unplanned

100

4,4

6,3

1,43

Maxaquene D, Planned

100

4,2

6,8

1,62

Maxaquene B, Unplanned

100

5,1

1,37

Polana Caniço A, Planned

3,9

4,9

1,26

Polana Caniço A, Unplanned

100

4,5

6,5

1,44

Planned areas average

23,33

90,00

93,33

4,10

5,80

1,41

Unplanned areas average

3,33

90,00

96,67

100,00

4,67

6,60

1,42

Table 2: Field interview data

Results The six indicators of urban form computed for each settlement under examination are summarised in table 1. The data show higher levels of built density (FAR), more compact urban form (SAV), higher levels of public space (PSR), and larger average street width (ASW) in all three planned urban areas compared to the respective three adjacent unplanned urban areas. On average the planned areas have a 14% higher FAR, 27% higher PSR, 20% higher ASW, and 10% higher SAV compared to the unplanned areas. The average block size (ABS) was 23% larger in unplanned areas. However, in one case (Maxaquene B and D) the ABS was almost identical in the adjacent planned and unplanned areas. The urban tree canopy cover (UTC) was on average 23% higher in unplanned areas. However, in one case (Maxaquene A) the UTC was slightly higher in the planned area. The results of the field interviews are summarised in table 2. The data show higher proportions of tenants in all three planned areas compared to the neighbouring unplanned areas. The data show identical levels of household access to water in the planned and unplanned areas. The data show

slightly lower levels of access to sanitation and electricity as well as slightly smaller dwelling size and household size in planned areas compared to unplanned areas. However, all the tenant respondents resided in a single room or two-room dwellings with an average dwelling size of 1,5 rooms and an average household size of 2,4 people. Furthermore, tenant households show lower levels of access to sanitation and electricity. Discussion This section discusses the results of the study, the wider theoretical implications of the findings, and possible policy responses to these. The study found significant variations in urban form and household conditions between planned and unplanned case study areas. All three planned areas feature higher built density, more compact urban form, higher proportions of public space, higher average street width, smaller average dwelling size, smaller average household size, and a higher proportion of tenants compared to the adjacent respective unplanned areas. Furthermore, on average the urban tree coverage, the levels of household access to electricity and sanitation, and average block size were lower in the planned areas compared to the unplanned

areas. Accordingly, the study suggests that urban planning has a long-term impact on both urban form and household conditions in contexts with limited state governance of the urban development. Regarding the differences between the planned and unplanned areas seen in household conditions, perhaps the most significant finding is the higher proportion of tenants found in all three planned areas. While the homeowner interview responses were largely consistent across planned and unplanned areas, the tenant households showed lower average levels of access to water and sanitation, smaller dwellings, smaller households, and more people per room. Accordingly, the differences in household conditions across the planned and unplanned samples areas are likely largely attributed to the higher proportion of tenants seen in the planned areas. In general, the indicators of basic livelihood were high across all sample areas, i.e. low proportion of households with overcrowding, lack of electricity, and inadequate access to water and sanitation. However, it is likely that more detailed inquiries into indicators of household conditions such as education level, income level, car ownership and quality of housing would have added more nuance to the socio-economic differences between the planned and unplanned areas. While rental housing provision is relatively limited in the informal settlements in Maputo compared to other major cities in the region, small-scale rental housing in the back yards of individual homeowners is prevalent in the informal settlements across the city (Jenkins, 2013; Mottelson, 2020a). Backyard rental housing provides a secondary income for homeowners and requires investment in the construction of the housing units (Jenkins, 2013). Accordingly, the higher proportion of tenants seen across all the planned areas may be attributed to higher levels of household resources in the planned areas. The urban fabric of the planned sample areas resembles the urban fabric of parts of the formal centre of Maputo which is largely seen as an ideal urban form in the city (Nielsen & Jenkins, 2020). Furthermore, the higher average street width indicates better access conditions for cars in the planned areas compared to the unplanned areas. These factors may constitute amenities increasing the demand for housing in such areas as argued by Smith (1978). Consequently, the increased demand for housing and land in the planned urban areas will likely lead to an increased market value of land in these areas. Accordingly, it is likely that such dynamics lead to small shifts in socio-economic conditions among residents through successive land transactions occurring over time. Accordingly, this study suggests that planned urban areas are generally seen as more desirable in Maputo which likely leads to an increased market value of land in these areas thereby resulting in homeowners with slightly more resources moving into the planned areas compared to the unplanned areas. The study suggests that homeowners in planned areas thereby have more resources for investments in rental housing units and that this mechanism accounts for the higher proportion of tenants in the planned areas compared to the unplanned areas. As residents of informal settlements typically have limited economic resources and limited formal financing options because their properties are

extra-legal and thus cannot be used as financial collateral, the investment capacity for construction is largely limited. Households in informal settlements of Maputo typically develop incrementally when the economic resources for home expansion are available and built densification is largely constrained by the household economy (Andersen et al., 2015a, 2015b). If households in planned areas on average have more resources than households in unplanned urban areas, this may in part account for the higher levels of built densities seen in the planned areas compared to the unplanned areas. Accordingly, the study suggests that higher levels of household resources in planned areas partially account for the higher levels of built density seen in the planned areas. Regarding the differences between the planned and unplanned areas seen in the urban form data, perhaps the most significant findings include the higher levels of built densities, higher levels of public space, and the lower levels of urban tree canopy cover seen in the planned areas compared to the unplanned areas. Urban densification and compact city development are advocated by UN-Habitat and OECD for the beneficial effects on sustainability, resilience, and economic growth as well as cutting the costs of service delivery and infrastructure provision (Organisation for Economic Co-operation and Development, 2012; UNHabitat, 2017). Accordingly, it is arguably significant to understand the drivers of the higher urban densities in the planned areas compared to the unplanned areas. Notably, the planned areas show both higher levels of public space and higher levels of built densities. Accordingly, urban densification does not necessarily compromise the levels of public space and access conditions in informal settlements as is also suggested in previous studies (Mottelson, 2020a; Mottelson & Venerandi, 2020). Higher levels of investment capacity derived from more economic resources among the residents of the planned sample areas may partially explain the higher built densities in the planned sample areas as argued in the previous paragraph. Furthermore, smaller plot sizes and more simple plot geometries are likely the main drivers of the higher urban densities in the planned sample areas aside from the possible higher investment capacity of the homeowners. The study suggests that the plot sizes in unplanned sample areas on average are larger than the approximately 10x15 metres plots in the planned sample areas. Smaller plots generally lead to higher household density and thereby also a likelihood of higher concentration of collective investment capacity. Accordingly, the study suggests that the plots are smaller in the planned areas and that this leads to higher residential density which leads to higher collective investment capacity enabling the development of higher built densities. The study thus argues that smaller plot sizes likely is a key factor explaining the higher built densities seen in the planned areas compared to the unplanned areas. Finally, the simple rectangular plot geometry seen in the planned areas likely increases the land-use efficiency. The standardized corrugated iron sheets (measuring 3600x700mm) used for roof-cladding are widespread in the informal settlements of Maputo. The layout of individual rooms in most dwellings

are adapted for economical optimization of the corrugated iron sheets resulting in simple rectangular geometry and dimensions corresponding to the length of one corrugated iron sheet. The incremental development of dwellings with single-room expansions built according to optimized use of the standardized construction materials have led to the emergence of the ‘Casa Ventoinha’ (fan house) housing typology (Carrilho, 2004). The typology resembles a fan when seen from above with four individual roof surfaces, expressing the interior division of the rooms. The rectangular geometry of the most common housing typology in the informal settlements of Maputo is likely more geometrically compatible with the simple rectangular geometry of the plots in the planned areas than the more complex irregular plot geometries seen in the unplanned areas. This may lead to more efficient use of construction materials and more optimized use of the space in the planned areas as the design of dwellings in the planned areas do not have to correspond to odd angles and irregular plot geometries. Accordingly, it is likely that the simpler rectangular geometry of plots in the planned areas partially accounts for the higher built densities and more compact urban form. The study thus argues that the higher built densities in the planned areas are driven by higher levels of household investment capacity, smaller plot sizes, and simpler plot geometries compared to the unplanned areas. Urban densification leads to improved mobility and more cost-effective investments in infrastructure in the context of Sub-Saharan Africa (Andreasen & Møller-Jensen, 2017). Accordingly, the study suggests that urban planning is important for sustainable development in the region. All three examined planned urban areas feature higher levels of public space and higher average street width compared to the adjacent examined unplanned urban areas. This is a significant finding as higher levels of public space and higher average street width space both improve the access conditions for service delivery and increase feasibility for implementation of infrastructure (Satterthwaite, 2011). Whitehand (2001) argues that the formation of streetsystems and plot boundaries are essential for the long-term urban development as they typically remain unchanged through successive generations of society. Accordingly, the difference between the planned and unplanned examined areas in terms of levels of public space and higher average street width is likely largely an outcome of the different conditions in which the areas were established. Furthermore, the simple uniform urban fabric of the planned examined areas may be easier for local authorities to maintain as it is likely easier to identify street encroachment in the planned areas compared to the unplanned areas. Consequently, the study suggests that urban planning leads to improved access conditions and higher levels of public space in contexts with limited state governance of the urban development. The study found a higher average urban tree canopy cover in the unplanned areas. Lack of trees leads to increasing surface urban heat island effect compromising local microclimate (Elmes et al., 2017). Accordingly, the lower level of urban tree canopy cover found in the planned areas may

compromise sustainable development. It is not clear what drives this development. Previous studies suggest levels of population density and urban tree canopy cover are not correlated and that higher levels of urban tree canopy cover are linked to higher socioeconomic levels (Heynen & Lindsey, 2003; Schwarz et al., 2015). However, as these studies were conducted in the United States of America these results may not be relevant in this context. Higher levels of built densities, higher levels of public space, and socio-economic factors may account for this development. Perhaps, the increased proportion of the space occupied by buildings in the planned areas partially accounts for the lower levels of urban tree canopy cover in the planned areas. Perhaps, the higher levels of public space partially account for the lower levels of urban tree canopy cover in the planned areas. Perhaps paved ground surface is a symbol of wealth and households with more economic resources cut down trees in order to pave the ground. However, more detailed studies on this subject are needed in order to qualify this discussion. While the study found higher levels of built density, public space, and average street width in all planned sample areas compared to the adjacent unplanned areas, the study also found some variations in these data across the three planned areas. The study argues that variations in the governance practices in the local neighbourhood administrative systems largely account for these differences. For example, the urban fabric of the planned area in Maxaquene A shows some irregularities which are likely the result of residents appropriating parts of the public space. As some of the local neighbourhood administration governance practice is not based on the formal regulation it is likely that such practices vary between the local neighbourhood administration offices. More specifically, some local administrations may be more tolerant of street encroachment than others. Furthermore, as Jenkins (2000a) suggests that bribes for provision of informal authorization in the local administration occur, perhaps some local administration may be more susceptible to bribery which may partially explain variations in public space of planned areas. Accordingly, the study suggests that variations in public space across the three planned case study areas are largely attributed to variations in local governance practices. This finding underpins the importance of the local administrative systems which to a large extent administer the urban development of the city. The study suggests that urban planning has a significant impact on the development of the urban form of informal settlements as higher levels of public space and built densities were found in the planned sample areas compared to the adjacent unplanned sample areas. This may have significant policy implications. Previous studies have shown that the cost of structural readjustment of the urban fabric of informal settlements is much more expensive than ‘greenfield’ developments (Lamson-Hall et al., 2019). Accordingly, the study underscores the significance of the implementation of planned urban structures before the urban form consolidates. Furthermore, the study suggests that urban planning may lead to increased feasibility and cost-effectiveness of implementation infrastructure due to

the higher level of public space and higher average street width. Additionally, urban planning may have positive effects on mobility due to the higher built densities and likely higher residential densities in the planned areas. Consequently, the study suggests urban planning has a significant long-term impact even in contexts with limited institutional capacity to enforce urban regulation and thus underpins the significance of allocation of public funds for the provision of spatial planning. Moreover, the study found lower levels of urban tree canopy cover in the planned sample areas which likely leads to increased surface urban heat islands. Accordingly, strategies to increase urban tree canopy cover in planned informal settlements should be considered a policy priority. Finally, as the local neighbourhood administrations to a large extent administer the urban development of the informal settlements in Maputo, these may be provided capacity building and additional resources in order to limit issues with street encroachment and improve the basis for issuing construction permits. Accordingly, the study argues that the capacities for urban governance in the local neighbourhood administrations should be strengthened and additional resources should be allocated for these to invest in locally decided priorities. Conclusion The study investigated the impact of urban planning on the development of the urban form of informal settlements through comparison of planned and unplanned sample areas in peri-urban Maputo. The study found significant variations between planned and unplanned case study areas in both urban form and household conditions. All three planned areas feature higher built density, more compact urban form, higher proportions of public space, higher average street width, smaller average dwelling size, smaller average household size, and a higher proportion of tenants compared to the adjacent respective unplanned areas. Furthermore, on average the urban tree coverage, the levels of household access to electricity and sanitation, and average block size were lower in the planned areas compared to the unplanned areas. Accordingly, the study suggests that urban planning has a long term impact on both urban form and household conditions in contexts with limited state governance of the urban development. The study suggests that planned urban areas are generally seen as more desirable in Maputo which likely offsets the market value of land in these areas thereby resulting in homeowners with slightly more resources moving into the planned areas compared to the unplanned areas. The study suggests that this mechanism accounts for the higher proportion of tenants in the planned areas compared to the unplanned areas as homeowners in planned areas thereby have more resources for investments in rental housing units. Accordingly, the study suggests that higher levels of household resources in planned areas partially account for the higher levels of built density seen in the planned areas. The study argues that smaller average plot sizes and simpler plot geometries further contribute to the higher urban densities in the planned sample areas. The study found higher levels of public space and average street width in planned areas which the study argues is a direct outcome of urban planning. The study found lower

levels of urban tree canopy cover in the planned areas. The study suggests that this may be an outcome of higher levels of built densities, higher levels of public space or more household resources. The study argues that urban planning leads to improved mobility and increased feasibility of investments in infrastructure. Accordingly, the study argues that urban planning should be given increased policy priority, particularly in peripheral areas where the urban form is not consolidated yet. The study argues that a strategy for increasing the urban tree canopy cover in informal settlements should be developed in order to improve the urban microclimate, increase biodiversity, and improve rain-water infiltration. Finally, the study argues that the local neighbourhood administration should be provided capacity building in urban governance and more economic resources for investments in locally determined priorities. References Álvarez, I. C., Prieto, Á. M., & Zofío, J. L. (2014). Cost Efficiency, Urban Patterns and Population Density When Providing Public Infrastructure: A Stochastic Frontier Approach. European Planning Studies, 22(6), 1235–1258. https://doi.org/10.1080/096543 13.2013.778957 Andersen, J. E., Jenkins, P., & Nielsen, M. (2015a). Who plans the African city? A case study of Maputo: part 1 – the structural context. International Development Planning Review, 37(3), 329–350. https://doi. org/10.3828/idpr.2015.20 Andersen, J. E., Jenkins, P., & Nielsen, M. (2015b). Who plans the African city? A case study of Maputo: part 2 – agency in action. International Development Planning Review, 37(4), 423–443. https://doi. org/10.3828/idpr.2015.25 Andreasen, M. H., & Møller-Jensen, L. (2017). Access to the city: Mobility patterns, transport and accessibility in peripheral settlements of Dar es Salaam. Journal of Transport Geography, 62, 20–29. https://doi. org/10.1016/j.jtrangeo.2017.05.005 Barros, C. P., Chivangue, A., & Samagaio, A. (2014). Urban dynamics in Maputo, Mozambique. Cities, 36, 74– 82. https://doi.org/10.1016/j.cities.2013.09.006 Berghauser Pont, M., & Haupt, P. (2009). Space, Density and Urban Form. NAi Publisher. https://repository. tudelft.nl/islandora/object/uuid:0e8cdd4d-80d04c4c-97dc-dbb9e5eee7c2?collection=research Bertaud, A. (2018). Order without Design: How Markets Shape Cities. The MIT Press. Carrilho, J. (2004). Traditional informal settlements in Mozambique: From Lichinga to Maputo. FAPF. Conzen, M. R. G. (1960). Alnwick, Northumberland: A Study in Town-Plan Analysis. Transactions and Papers (Institute of British Geographers), 27, iii. https:// doi.org/10.2307/621094 Dibble, J., Prelorendjos, A., Romice, O., Zanella, M., Strano, E., Pagel, M., & Porta, S. (2019). On the origin of spaces: Morphometric foundations of urban form evolution. Environment and Planning B: Urban Analytics and City Science, 46(4), 707–730. https:// doi.org/10.1177/2399808317725075

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Inadequate infrastructure in Maxaquene, Maputo, Mozambique → 100

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103 Small-scale public space in Mafalala, Maputo, Mozambique

ISUF 2020: CITIES IN THE TWENTY-FIRST CENTURY

URBAN DENSIFICATION OF INFORMAL SETTLEMENTS IN SUB-SAHARAN AFRICA: AN ANALYSIS OF RECENT DEVELOPMENTS IN MAPUTO, MOZAMBIQUE Johan Mottelson, PhD Student, KADK - The Royal Danish Academy of Fine Arts Schools of Architecture, Design and Conservation, Denmark

ABSTRACT Despite the rapid urbanization characterizing Sub-Saharan Africa, limited scholarly works have investigated the urban densification in African cities. This paper examines built densification of three unplanned informal settlements and developments of population densities in Maputo, Mozambique. The study is based on analysis of satellite images and census data from 2007 and 2017. The study found increasing built densities in all three case study areas and decreasing population densities in two case study areas. Accordingly, increasing built densities do not necessarily lead to increasing population densities. The study corroborates recent studies suggesting that the urban population growth in Sub-Saharan Africa is mainly accommodated through urban expansion. The study found limited variation of population densities and built densities despite different distances to the city center. The paper argues that this is caused by limited investment capacities of the landholders and large informal land supply. The paper suggests that centrality is less significant for development of built densities in informal settlements where residents hold the land due to limited investment capacity. The paper argues that policy-makers should prioritize establishment of roads in peripheral areas financed through road-pricing in order to curb the urban expansion and improve the resiliency of peripheral areas. Keywords: urban morphology, urban densification, urban expansion, Sub-Saharan Africa, Mozambique, Maputo INTRODUCTION In 2009, less than 40% of the population in Africa resided in cities. However, according to demographic projections, the urban population will surpass the rural population approximately by 2030 due to extensive urbanization processes (UN-Habitat, 2020). The rural to urban migration and high fertility rates lead to large-scale urban transformations of African cities in order to accommodate the urban population growth. In Sub-Saharan Africa, the urban majority resides in informal settlements. These are urban areas typified by lack of state control (Jenkins, 2006). More specifically, informal settlements are characterized by construction that does not comply with planning and building regulations or construction on land which the occupants have no legal claim to (OECD, 2008). Informal settlements proliferate due to urban poor majorities lacking the resources to comply with regulation along with limited state capacity to administer the urban growth (Yeboah & Briggs, 2001). Urban densification is advocated as benefitting sustainability, resilience, and economic growth as well cutting the costs of service delivery and infrastructure provision (OECD, 2012; UN-Habitat, 2017). However, recent studies suggest that cities in Sub-Saharan Africa are undergoing rapid urban expansion with low density developments compromising sustainable development (Xu et al, 2019). Nevertheless, limited studies have focused on the concurrent urban densification taking place within the built-up urban fabric. The lack of knowledge on urban densification of informal settlements compromises development of efficient urban planning and policy (Owusu, 2013). This paper analyses developments of built densities and population densities of unplanned informal settlements in periurban Maputo, Mozambique in order to contribute to the knowledge on the development of informal settlements in Sub-Saharan Africa and enhance the efficacy of urban planning and policy targeting such areas. Limited investments in infrastructure compromises mobility in peripheral low-density areas of African cities due to inadequate provision of roads, traffic congestion, insufficient public transport systems, and vast distances within the expanding cities (Satterthwaite, 2011). Simultaneously, the densification 104

of the built-up urban fabric exacerbates problems with public hygiene in centrally located dense neighborhoods due to limited sewage and storm water management systems along with increased risk of contamination caused by high population densities (Andreasen & Møller-Jensen, 2017). Accordingly, urban sprawl and densification discussions may be simplified to a trade-off between public hygiene and mobility in the context of Sub-Saharan Africa. Costs of infrastructure are largely determined by the size of the area while the impact of implemented infrastructure is largely determined by the population density. Consequently, impact assessments and cost benefit analyses of infrastructure investments largely depend on urban density measures. As the infrastructure deficit in Sub-Saharan African cities constitutes a major issue confronting contemporary urban development, density measures are increasingly important for efficient use of resources in urban planning and policy.

Figure 1. Inadequate infrastructure and public transportation systems in Maputo.

. Figure 2. Maxaquene A, a centrally located informal settlement in Maputo.

Different urban models have been developed in order to describe the relationship between location, land value, land use, and urban densities. The cost of friction hypothesis underscores the relation between centrality and built densities by suggesting that land values are determined by transportation costs to the city center and that these determine the land use and densities (Haig, 1926). The concept was further developed in the sector model, highlighting that different sectors surround the Central 2 ISUF 2020 Cities in the Twenty-first Century

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Business District (CBD) and radiate outward along transportation routes from the city center (Hoyt, 1939). The Spatial Equilibrium Model assumes that differences across space in productivity, amenities, and the construction sector drive differences in density, incomes and home prices (Alonso, 1964; Mills, 1967; Muth, 1969). Bertaud (2018) argues that density is an indicator of land consumption, reflecting the equilibrium between supply and demand for land in a specific location. Population density is thus an indicator dependent on market parameters, mainly household income, land supply elasticity, and transport speed and cost. This implies that housing costs plus transport costs are constant across space and that housing costs will decline as transport costs rise with distance to the city center. However, Kombe (2005) argues that theories of land rent and spatial structures of cities do not apply to the organic form of informal settlements. Visagie and Turok (2020) argue that the relationship between location and urban density of informal settlements in SubSaharan Africa remains under-researched. This paper seeks to improve the knowledge of this relationship by examining developments of built densities and population densities in Maputo, Mozambique as well as discussing factors driving these developments. The paper includes analysis of developments of tree canopy cover in order to asses the impact of densification on the biodiversity and microclimate. Furthermore, the paper analyses developments of public space in order to assess conditions for access and implementation of infrastructure. Finally, the paper discusses a number of policy proposals to address issues with low mobility and public hygiene based on the findings. METHODOLOGY This study is based on official census demographic data from the Mozambican government and selfproduced spatial data based on Google Earth satellite images. Longitudinal data was used in order to examine the development over time. The demographic data was examined to assess the distribution of population across space. The spatial data was examined to assess the relationship between the distribution of population across space and the built environment. The spatial data includes indicators of built density, public space, and tree canopy cover for three case study areas. The built density was examined to assess the relationship between population density and built density. The public space was examined to assess the impact of built densification on the street network, with possible implications on mobility, public hygiene, and economic performance. The tree canopy cover was examined to assess the impact of built densification on the environment as private yards constitute the largest green space type in the city. The census data was taken from the National Institute of Statistics (Instituto Nacional de Estatística) website in 2018. The census data presents recorded population for the city across the 2007 and 2017 national censuses in individual districts within the municipality and neighboring municipality of Matola, Marracuene district, and Boane district comprising the greater Maputo metropolitan area. The self-produced data is based on three case study areas of unplanned settlements of Maputo. Cases with different distances to the city centers were selected in order to assess the significance of centrality for the development of built densities. All three areas are characterized by unplanned spatial structures and all three areas are relatively homogenous residential areas without any major roads, industry, businesses or public institutions, thus enabling data extraction relevant for comparison. The study examined 300x300 meter areas located in Maxaquene A, Hulene, and Guava. Satellite images of all three areas were extracted from Google Earth. These were recorded the following dates: Maxaquene A: 16.09.2007, 03.05.2017; Hulene: 16.09.2007, 03.05.2017; Guava: 12.01.2007, 03.05.2017. The satellite images were imported and scaled in AutoCad. Buildings, streets, and trees were traced on separate layers. Each layer was subsequently joined using the Region and Union commands and the total area and number of entities for each layer was extracted from the properties bar. Attributes for total building coverage, number of buildings, total public space size, tree canopy coverage and number of trees were extracted using this method. All buildings in the three settlements were single-story. Accordingly, the floor area ratio was calculated based on the total building footprint area divided by the total sample area. Similarly, public space ratio and tree canopy

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cover ratio was calculated using this method. Parts of the data were used in a separate study (Jenkins & Mottelson, 2020). CONTEXT Mozambique is located in South East Africa and is one of the poorest countries in the world. Maputo is the capital of the country and the city is characterized by a formal urban center surrounded by informal settlements to the West and North as well as the Maputo Bay to the East and South. The urban center was established in 1781 by Portuguese colonialists, while the majority of the informal urban areas were established after independence in 1975. The urban development after independence was characterized by a large influx of rural population due to the ongoing civil war causing large numbers of refugees along with abolishment of previous restrictions on movement of people (Jenkins, 2000). Maputo consists of 7 administrative districts. District 1 covers the formal city center, district 2-5 cover the largely informal urban areas to the North and West of the center, while district 6-7 cover the island of Inhaca and Katembe south of the bay, which was connected to the city via a new bridge in 2018. However, the continuous urban fabric of the greater Maputo metropolitan area includes the neighboring Matola Figure 3. Maputo overview. Municipality as well as Marracuene and Boane districts (Barros et al., 2014). This study includes sample areas in Maxaquene A, Hulene and Guava, respectively one, five and 20 km from the formal city. The three case study areas are located in district 3, district 4, and in Marracuene district beyond the municipal boundaries. Maxaquene and Hulene were largely developed during the influx of population subsequent to independence (Pinsky, 1982) while Guava was developed during the period under examination. RESULTS The 2007-2017 national census data shows 1% population growth within the Maputo Municipality during the ten-year period. However, the population of the Greater Maputo Metropolitan area grew approximately 60% in the same period. Accordingly, the population growth of the city primarily occurred beyond the municipal boundaries, in neighbouring Matola Municipality, Marracuene District and Boane District. The data shows large variations in population growth between districts within the Maputo Municipality, as the three most centrally located districts had negative population growth, while the remaining districts had increasing populations during the ten-year period. The average household size decreased within the Maputo Municipality. The spatial data shows increasing building coverage and decreasing tree coverage in all three case study areas from 2007-2017. The public space decreased in Maxaquene A and Hulene and increased in Guava. While the numerical increase in Floor Area Ratio (FAR) was relatively low, the case study area in Maxaquene A which had the highest FAR in both 2007 and 2017 showed the lowest proportional increase, while Hulene showed moderately higher numerical and proportional increase of FAR and Guava showed very high numerical and proportional increase of FAR.

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Population 2007

2007 p/h

Population 2017

2017 p/h

2007-17 change (%)

1,094,305

5.0

1,101,170

4.9

District 1 - KaMphumu

107,530

4.0

80,550

3.4

-25%

District 2 - Nlhamankulu

155,385

5.1

129,306

5.4

-17%

District 3 - KaMaxakeni

222,756

5.4

199,565

5.6

-10%

District 4 - KaMavota

293,361

5.2

331,968

5.0

13%

District 5 - KaMubukwana

290,696

5.0

321,438

4.9

11%

KaTembe

19,361

4.3

32,248

3.5

67%

KaNyaka

5,216

5.4

6,095

4.1

17%

Matola Municipality

672,508

4.8

1,616,267

4.4

140%

Boane District

104,627

210,498

101%

Marracuene District

87,183

230,530

164%

1,920,261

3,070,259

60%

Maputo Municipality

Greater Maputo

Figure 4. Population and people per household of Greater Maputo 2007-2017, (INE, 2018).

Figure 5. Population growth by administrative area 2007-2017, (INE, 2018).

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Figure 6. Case study areas 2007-2017

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Figure 7. Case study areas 2007-2017

Figure 8. Case study areas 2007-2017

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Maxaquene A, 07

Maxaquene A, 17

Hulene, 07

Hulene, 17

Guava, 07

Guava, 17

Floor area ratio

0.30

0.36

0.19

0.25

0.01

0.06

Number of buildings

482

537

284

348

0.1080

0.0970

0.1232

0.1209

0.0460

0.0984

Tree canopy cover ratio

0.07

0.05

0.16

0.14

0.12

Number of trees

137

122

348

261

160

255

Public space ratio

Figure 9. Spatial data extracted from case study areas 2007-2017.

Maxaquene

Hulene

Guava

Floor area ratio 2007-2017 change

21%

32%

723%

Number of buildings 2007-2017 change

11%

23%

357%

Public space ratio 2007-2017 change

-10%

-2%

114%

Tree canopy cover 2007-2017 change

-30%

-45%

-12%

Figure 10. Changes in spatial data extracted from case study areas 2007-2017.

DISCUSSION The study found significant population growth in the periphery of the city along with negative population growth in the three most centrally located districts. This represents a center to periphery shift of the spatial distribution of the population. The study thus supports other recent works suggesting that growing urban populations in Sub-Saharan Africa increasingly are accommodated through urban expansion. This development may compromise the efficacy of future investments in infrastructure due to decreased population densities. Furthermore, while built densification occurred in all three sampled areas, the peripheral areas show higher numerical and proportional increase of built densities, underscoring the center to periphery development. The study suggests that increasing built densities do not necessarily lead to increasing population densities and do not necessarily enhance the sustainable aspects of compact city development due to the increased space consumption per capita. The decreasing population densities in more central areas are likely caused by decreasing household sizes, economic development, and increased commercial activities in the center. Decreasing household sizes lead to decreased population density if the number of households remain constant and may thus partially account for the development. Economic development can lead to increased space consumption as increased resources may enable vertical or horizontal expansion of housing units. As commercial functions are concentrated in the CBD, the growth of the city and consequent increased competition for central areas may have caused increasing pressure to convert residential space into commercial space, which may partially account for the decreasing population densities in the center. The parallel urban expansion is likely primarily driven by relatively cheap and accessible peripheral land and low transportation costs. Particularly, the lack of state control of the land market and consequent vast availability of low-cost informal land, subdivided and sold in the periphery of the city without formal planning, provides affordable options for accommodation and is thus likely a primary driver of the urban expansion.

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As residents of informal settlements typically have limited economic resources and cannot obtain loans in banks as their properties are extra-legal, the investment capacity for construction is largely limited. Households in informal settlements typically develop incrementally when economic resources for expansion are available (Andersen et al., 2015). As overcrowding is common in informal settlements, expansions of households are typically desired. However, built densification is largely constrained by the household economy. Accordingly, the limited built densification of the more central informal settlements may be a result of limited investment capacity of the landholders. The limited share of tenants in the informal settlements of Maputo (Jenkins, 2013), may amplify this development as the landholders have limited additional income from tenants and thereby fewer resources for investments. The Guava case study area was largely undeveloped in 2007 and had suburban levels of built density in 2017, while the other two cases were already developed in 2007. Although the three cases are located at different distances to the city center, the study found relatively little variation in built densities. Aside from the relatively low transportation costs, the limited variations in built density may in part be a result of low standards of initial construction. After the household is established, the level of expansion may be curbed by costs of home improvements and maintenance, thereby limiting the urban densification subsequent to the initial rural to urban land-use change. The decreased public space in the case study areas in Maxaquene A and Hulene are likely caused by street encroachment by local residents. However, as the amount of public space in both cases were relatively low in 2007 the decrease in public space was minor. The public space increased in the case study area in Guava during the same period, as land was subdivided into residential plots and new roads were established to access the smaller plots. The data thus suggests that public space increases during the initial formation of informal settlements and subsequently decreases due to street encroachment and land grab. This development compromises access conditions as well as infrastructure provision as street spaces become narrower. In the more extreme cases, the development has negative implications for public hygiene and mobility. The study found decreasing tree canopy cover in all three cases and decreasing number of trees in Maxaquene A and Hulene along with increasing number of trees in Guava. The decreasing tree canopy cover may be explained by the increasing urban densities as construction of buildings take up land previously occupied by the trees. In the Guava case, the expansion of the streets in the area may have been an additional contributing factor. The increasing number of trees in Guava suggests that the residents planted trees when transforming the area from semi-rural to a suburban residential area. The built densification likely leads to decreased tree canopy cover with possible negative implications for urban microclimate, biodiversity, and rainwater infiltration. The newly established ring road, along with the new bridge to Katembe, will likely decrease transportation costs to peripheral areas, if not directly, then indirectly through decreased time spent on commuting to the center. According to the cost of friction hypothesis and the Spatial Equilibrium Model, these major infrastructure instalments will likely increase urban development along these transportation routes, and thus further increase the urban expansion. However, increasing gasoline prices and traffic congestion caused by increasing urban population and economic development may have the opposite impact. The likelihood of continued lack of state control of the land markets in the neighboring districts and municipalities will likely maintain the supply of affordable land on the market. It is thus likely that the current urban expansion will continue in the coming years in Maputo which may result in decreased impact of investments in infrastructure and increased resource consumption. Road pricing is already used on the main traffic artery between Matola and Maputo. Similarly, road pricing could be considered for accessing the new ring road in the northern periphery of the municipality, in order to generate public revenue, decrease traffic congestion, decrease the CO2 emissions, and curb the urban expansion. This may create a market based ‘green-belt’ effect, which would otherwise require land management capacities which local authorities lack. Exemption of public transport for the road pricing may ensure a more socially balanced urban development and provide incentives for the middle class who can afford investments in infrastructure to settle within the 9 ISUF 2020 Cities in the Twenty-first Century

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municipal boundaries and drive the urban densification. The government may consider supporting the local authorities in countering land grab and street encroachment in order to increase mobility, improve public hygiene and lower costs of upgrading the infrastructure. Finally, the government may consider establishing roads in peripheral areas in one-kilometer grids in order to establish street networks for traffic and public transportation for the future urban expansion before the settlements consolidate and thereby constrain implementation of such basic infrastructure. REFERENCES Alonso, W. (1964). Location and land use: Toward a general theory of land rent, Cambridge, MA.: Harvard University Press. Andersen, J. E., Jenkins, P. & Nielsen, M. (2015). Who Plans the African City? A Case Study of Maputo: Part 2 – Agency in Action. International Development Planning Review (IDPR) Vol. 37 (4). Andreasen, M. & Møller-Jensen, L. (2017). Access to the city: Mobility patterns, transport and accessibility in peripheral settlements of Dar es Salaam, Journal of Transport Geography, Vol. 62, 2029 Barros, C. P., Chivangue, A., Samagaio, A. (2014). Urban dynamics in Maputo, Mozambique, Cities, Vol. 36, 74-82 Bertaud, A. (2018). How markets shape cities. Cambridge, MA.: MIT Press. 143-219. Haig, R. M. (1926). Towards an Understanding of the Metropolis. Quarterly Journal of Economics, Vol. 40 (2), 402-434. Jenkins, P. (2000). City profile: Maputo, Cities, Vol. 17 (3), 207-218. Jenkins, P. (2006), Informal Settlements: Infernal and Eternal? The role of research in policy advocacy and urban informal settlements in Angola. In M. Huchzermeyer, A. Karam, (Eds.) Informal Settlements: A Perpetual Challenge?, (1st ed., pp. 84-100). South Africa: University of Cape Town Press. Jenkins, P. (2013), Urbanization, Urbanism, and Urbanity in an African City: Home Spaces and House Cultures, United Kingdom: Palgrave Macmillan. 112-128. Jenkins, P. & Mottelson, J. (2020). Understanding Density in Unplanned and Unregulated Settlements of Peri-urban Africa: A Case Study of Maputo, Mozambique. In M, Rubin, A, Todes, P., Harrison, A. & A. Appelbaum, (Ed.), Densifying the City? Global Cases and Johannesburg (1st ed.), United Kingdom: Edgar Elgar Publishing. Kombe, W. (2005). Land use dynamics in peri-urban areas and their implications on the urban growth and form: the case of Dar es Salaam, Tanzania. Habitat International, Vol. 29 (1), 113-135. Mills, E. (1967). An Aggregative Model of Resource Allocation in a Metropolitan Area. The American Economic Review, Vol. 57 (2), 197-210. Muth, R. (1969). Cities and Housing: The spatial Pattern of Urban Residential Land Use. United States: University of Chicago Press. OECD (2008). OECD Glossary of Statistical Terms, France: OECD Publishing. Page 267. OECD (2012). Compact City Policies: A Comparative Assessment, France: Organisation for Economic Co-operation and Development. Owusu, G. (2013). Coping with Urban Sprawl: A Critical Discussion of the Urban Containment Strategy in a Developing Country City, Accra. Planum: The Journal of Urbanism, Vol. 1 (26). 10 ISUF 2020 Cities in the Twenty-first Century

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Pinsky, B. (1982). The Urban Problematic in Mozambique: Initial Post-Independence Responses, 1975-80, Canada: University of Toronto Press. Satterthwaite, D. (2011). Upgrading dense informal settlements; the potential for health and wellbeing. Cities, Health and Well-Being. UN-Habitat (2017). The New Urban Agenda. Kenya: United Nations Settlement Programme, 15-25. UN-Habitat (2020). Sub-Saharan Africa Atlas, Kenya: United Nations Human Settlements Programme, 3-4. Visagie, J., & Turok, I. (2020). Getting urban density to work in informal settlements in Africa. Environment and Urbanization. Xu, G., Dong, T., Cobbinah, P., Jiao, L., Sumari N., Chai, B. & Liu, Y. (2019). Urban expansion and form changes across African cities with a global outlook: Spatiotemporal analysis of urban land densities, Journal of Cleaner Production, Vol. 224, 802-810. Yeboah, I. & Briggs, J. (2001). Structural Adjustment and the Contemporary Sub-Saharan African City. Area, Vol. 33, 18-26. CORRESPONDING AUTHOR Johan Mottelson, PhD Student, Johan Mottelson, PhD Student, KADK - The Royal Danish Academy of Fine Arts Schools of Architecture, Design and Conservation, Philip de Langes Allé 10, 1435 Copenhagen, Denmark, jmot@kadk.dk

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Vibrant street life in Katanga, Kampala, Uganda →

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Article

A Fine-Grain Multi-Indicator Analysis of the Urban Form of Five Informal Settlements in East Africa Johan Mottelson 1, * 1

and Alessandro Venerandi 2

Institute of Architecture, Urbanism and Landscape, KADK—The Royal Danish Academy of Fine Arts—Schools of Architecture, Design and Conservation, Philip de Langes Allé 10, 1435 Copenhagen, Denmark UMR 7300 ESPACE, University of Cote d’Azur, 98 Bd Herriot-BP 3209, 06200 Nice, France; alessandro.venerandi@univ-cotedazur.fr Correspondence: jmot@kadk.dk; Tel.: +45-3013-1001

Received: 12 June 2020; Accepted: 5 July 2020; Published: 9 July 2020

Abstract: Few studies have investigated the urban morphology of informal settlements at fine-grain level, limiting effective urban planning and policies targeting such areas. This study presents a high-resolution morphological analysis of five informal settlements located in central areas of major cities in East Africa. The analysis is based on indicators of urban form, statistical comparison, and field interviews on household conditions. The method improves the replicability and increases the spatial granularity compared to previous studies. Outcomes show that all case studies are characterised by organic street layouts. Three settlements form a comparable group with denser urban fabrics (small block size, high coverage ratios, and small private spaces), while the remaining two cases have less compact forms. The field interviews show high rates of tenancy, overcrowding, and inadequate access to water and sanitation in the first group and low rates of these conditions in the second group. We suggest that these differences are partially an outcome of levels of informal land supply. We argue that decreased informal land supply leads to increased competition and higher prices of accommodation, leaving fewer household resources for infrastructure investments and consequent compromised livelihoods. Accordingly, we argue that some modes of informal urban development should be accepted in Sub-Saharan Africa. Keywords: informal settlements; urban morphology; urban form; mixed methods; Sub-Saharan Africa; East Africa

1. Introduction In Sub-Saharan Africa, the urban majority resides in informal settlements, characterized by limited state control of the urban development, inadequate infrastructure, and compromised livelihoods. The likelihood of continued high population growth, high rural-to-urban migration and limited state capacity to administer the consequent urban growth will likely result in continued proliferation of informal urban development [1]. Accordingly, improving knowledge on the formation and development of informal settlements is of increased importance in the African context. Although the use of the UN-defined ‘slum’ term is contested [2], it specifies some of the challenges facing informal urban development, i.e., substandard housing, overcrowding, insecure tenure as well as inadequate access to water and sanitation [3]. However, spatial factors and urban form such as inadequate access conditions, inefficient use of space, high ground occupation, and limited public space are not included in the definition, even though they arguably constitute fundamental urban deficiencies. The work presented in this paper seeks to contribute to the understanding of informal settlements through the analysis of urban form. Urban Sci. 2020, 4, 31; doi:10.3390/urbansci4030031

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Urban morphology is the study of the form of human settlements with the aim of describing their spatial structures and understanding the process of their development [4]. The research field has developed different methods of classifying urban typologies based on quantitative and qualitative data. In recent years, quantitative studies have emerged, in part as a result of technological development, which have advanced the understanding of urban environments through digital processing and statistical analysis of large-scale fine-grained data sets. Such studies have found links between urban form and a wide range of issues, such as health, energy consumption, and liveability of neighbourhoods [5–7]. However, such analyses have only been applied to the study of informal settlements to a limited degree, particularly in the context of Sub-Saharan Africa. Several scholars in this field have developed theories on the form and development of informal settlements. Davis [8] suggests a typological classification of informal settlements based on location, formal/informal conditions and proximity to job opportunities. Dovey and King [9] outline eight typologies of informal settlements (districts, waterfronts, escarpments, easements, sidewalks, adherences, backstage, and enclosures) based on the process of settling on unclaimed land as indigenous villages, inserting into the leftover urban space, and attaching onto the structures of the formal city. However, these typological models primarily focus on the relation between entire informal settlements and the wider urban context and thus lack focus on the spatial structures within the settlements. Iovene et al. [10] argue that informal settlements develop similarly to premodern cities based on a comparative study with several urban form metrics, focusing on an informal settlement in Lima, Peru, and a neighbourhood in Venice, Italy. Hillier et al. [11] argue that spatial and locational factors influence the development and level of consolidation of informal settlements, based on analysis of informal settlements in Santiago, Chile. The study found that options for development of edge-oriented commercial activity and consequent participation in the wider local economy is determined by the levels of spatial integration within the surrounding context and is significant for consolidation of the built form of informal settlements. However, Hillier et al. primarily focus on features of the street network, thus missing further aspects of the built environment, while Iovene et al., although focused on multiple aspects of urban form, proposed a method difficult to replicate as it is based on fine grained spatiotemporal data, hardly obtainable for multiple informal settlements. This paper presents some of the first high-resolution urban morphology analyses of multiple informal settlements in Africa and discusses possible drivers for spatial variations. This study features a mixed approach, including eight spatial factors derived from high-resolution maps, statistical comparison, field interviews, and field observations. The spatial factors include block size, coverage ratio, floor area ratio, private and public space ratios, surface area to volume ratio, average node degree, and average betweenness. The proposed mixed approach overcomes the limitations of previous methods, as it is based on multiple descriptors of urban form, is replicable, more statistically robust, and provides outcomes at an unprecedented level of detail. In this paper, it is applied to data from informal settlements located in central areas of Antananarivo, Dar es Salaam, Kampala, Nairobi, and Maputo to address the following research questions: what are the morphological similarities across these settlements? What are the morphological differences? What are the drivers of these similarities and differences? 2. Methodology The methodology presented in this paper is based on four parts: acquisition of spatial data, field interviews, computation of the indicators of urban form, and statistical comparison. 2.1. Acquisition of Spatial Data Two techniques were used to obtain data at a fine level of spatial granularity. The former relied on the use of an unmanned aerial vehicle (drone), for systematic collection of high-resolution aerial imagery, and Pix4D, a photogrammetry software (https://www.pix4d.com), for processing the images and generating high-resolution georeferenced orthophotos, Digital Surface Models (DSMs), and 3D models

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of the surveyed areas. Since orthophotos cannot fully map the intricate path systems typical of informal settlements, these were mapped by walking along the boundaries of every block in each settlement with a handheld GPS device (smartphone) equipped with SW Maps (http://swmaps.softwel.com.np/#), an app that records GPS traces. The GPS traces and the high-resolution orthophotos were then automatically scaled in GIS and subsequently exported in a design software application. Here, all buildings were traced manually based on the orthophotos. Multi-storey buildings were identified using the elevation maps and the 3D models and separate layers were created for each floor. Finally, street networks and blocks were manually drawn based on the GPS traces and orthophotos, respectively. Buildings, blocks, and street networks in vector format constituted the base files for carrying out the spatial analysis presented in this paper. 2.2. Field Interviews The field interviews were carried out alongside the physical surveys. Ten residents of each neighbourhood were interviewed based on random selection, in different parts of the neighbourhoods. This entailed a fairly even distribution of gender and relative socioeconomic diversity among the interviewees within each context. The questions included household access to water, sanitation and electricity, as well as household size, dwelling size, whether the respondent was a tenant or house owner, and monthly cost of rent. As such, the questions included three of five of the UN-defined indicators of slums (overcrowding and household access to water and sanitation) [3]. We acknowledge that ten residents might not be fully representative of the case studies considered. However, random selection and diversity of gender and socioeconomic status of the interviewees contravene, to a certain extent, to this issue. Surveys for each settlement were carried out during the following periods of time: Antohomadinika, Antananarivo (Madagascar): February 2019; Katanga, Kampala (Uganda): May 2019; Kibera, Nairobi (Kenya): May 2019; Maxaquene, Maputo (Mozambique): May 2019; Hananasif, Dar es Salaam (Tanzania): January 2020. 2.3. Indicators of Urban Form To characterise the urban form of the settlements under examination, we used a set of eight indicators at the block level. These were computed in GIS and through the Momepy Python library [12]. Six of these indicators are widely used in the fields of urban design and morphology. Two are more experimental. The former include: • • • •

•

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Block size (BS) corresponds to the total area of each block; Coverage ratio (CR) quantifies the percentage of land which is occupied by buildings in each block. It is computed by multiplying the sum of the building footprints in each block by 100 and by dividing this value by BS; Floor area ratio (FAR) measures the built-up density of the block. It is calculated by summing up the gross floor areas (GFAs), obtained by multiplying building footprints by number of floors, of each building pertaining to the block and by dividing such value by BS; Surface area to volume ratio (SAV) quantifies the level of fragmentation of the building envelopes in each block. Typically, a simple box-shaped building would have a small SAV, as it is compact and thus does not have any protruding parts or cavities. On the contrary, a complex building with many recesses and/or protruding elements would have a greater SAV. This indicator is largely used in studies focusing on the energy efficiency of buildings. See, for example, the work by Ratti et al. [13]. SAV is computed by multiplying the perimeters of the buildings in each block by their relative heights, summing two times the sum of the building footprints in each block to this value, and by dividing this sum by the total built-up volume in each block; Average node degree (AND) measures the level of connectivity at the block level. It is computed by averaging the node degrees relative to the street intersections surrounding each block. In practice, a block surrounded by many dead-end streets (i.e., node degree equals 1) would have

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a low average node degree and thus low local connectivity. Conversely, a block surrounded by several four-way intersections (i.e., node degree equals 4) would have a greater average node degree and thus higher local connectivity. Node degree is a widespread measure of network connectivity used, for example, in social networks [14] and communication [15]. Average betweenness at 400 m (AB400) measures through movement in street networks. It was reported to correlate with several urban phenomena such as concentration of commerce and services [16], employment density [17], and street quality [18]. The formula of betweenness centrality [19] can be adapted to output levels of through movement at different urban scales (e.g., neighbourhood, district, or city region). Since the settlements under examination have sizes comparable to that of city neighbourhoods, we computed betweenness centrality on their street networks with a radius of 400 m, a measure typically associated with the neighbourhood scale [20]. Finally, each block was assigned with the average value of betweenness centrality of its surrounding streets.

The experimental indicators presented next are both variations of the open space ratio (OSR), which is computed by dividing the non-built space in the block by its total GFA [21]. While OSR does not make distinction between non-built public and private spaces, our indicators do. More specifically: • •

Private space ratio (PrSR) quantifies the amount of private space relative to the built-up density. It is computed by subtracting the sum of building footprints from BS and by dividing this value by the sum of the gross floor areas (GFAs) of each building within the block. Public space ratio (PuSR) measures the amount of public space relative to the built-up density. The amount of public space in each block is obtained by subtracting BS from the area of the polygon enclosed by the road centre lines surrounding each block. PuSR is computed by dividing such value by the sum of the gross floor areas (GFAs) of each building within the block.

2.4. Statistical Comparison To investigate possible patterns of similarity across the settlements, we produced density distribution plots of the eight indicators of urban form and applied the Kolmogorov–Smirnov test (KS test). The former is a way of visualising data over a continuous interval through a kernel smoother function that reduces the noise and renders distribution functions easier to compare [22]. The latter is a non-parametric null hypothesis test that assesses the statistical similarity between two distribution functions [23]. In practice, the KS test measures the distance between the empirical distributions of two variables, under the null hypothesis that they are taken from the same distribution. Thus, if the null hypothesis can be retained, i.e., the p-value of the test is above 0.01 (corresponding to a confidence level of 99%), the distance between the tested distributions is small and the similarity is confirmed. Conversely, if the null hypothesis is rejected, i.e., the p-value of the test is below 0.01, the distance between the tested functions is greater, thus they are not similar. The KS test was applied to assess similarities among the distribution functions of the eight indicators presented in the previous section, across all possible combinations of settlements. 3. Case Studies The case studies considered in this paper (i.e., Antohomadinika, Hananasif, Katanga, Kibera, and Maxaquene) were selected for being representative of informal urban development in different East African metropolitan contexts. More specifically, they all feature a low-income population, unplanned/organic urban form, and are centrally located, thus representing some of the densest informal urban areas within their respective contexts. The processed orthophotos and vector maps for each settlement are presented in Figure 1, while brief descriptions for each case study, based on field observations, are presented next.

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Figure 1. Orthophotos and vector maps of the five settlements under examination.

Antohomadinika is located approximately 1 km from the central business district (CBD) of Antananarivo, the capital Madagascar. The settlement is characterized multi-storey Antohomadinika is of located approximately 1 km from the central by business districtbuildings, (CBD) of high ground occupation, limited public space and poor public hygiene due to the frequent flooding of Antananarivo, the capital of Madagascar. The settlement is characterized by multi-storey buildings, the area, in part due to the low-lying terrain. The vast majority of the buildings have small footprints, high ground occupation, limited public space and poor public hygiene due to the frequent flooding

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of the area, in part due to the low-lying terrain. The vast majority of the buildings have small footprints, indicating small plot sizes. Antananarivo features mountainous orography and distinctive

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indicating small plot sizes. Antananarivo features mountainous orography and distinctive large-scale agriculture intertwining the urban neighbourhoods. These are largely rice fields, characterised by wetland conditions. Hananasif is located approximately 3 km from the CBD of Dar es Salaam, the largest city in Tanzania. The settlement is characterized by single-storey detached housing units and relatively wide streets, allowing access for cars. It is surrounded by wetlands to the South-West, South and East. Its landscape slopes following these directions, while more central areas stay relatively flat. Dar es Salaam is characterized by a formal urban centre surrounded by a continuous belt of informal urban development with some enclaves of formal areas, stretching approximately 30 km into the land. Katanga is located approximately 2 km from the CBD of Kampala, the capital of Uganda. It is located next to the main city hospital and is surrounded by formal urban areas. The urban fabric of Katanga is mostly characterized by single-storey dense clusters of buildings and parking lots in the periphery of the settlement. Kampala is characterized by intertwined formal and informal areas. Kibera is the largest informal settlement in Africa [24] and is located approximately 5 km from the central business district (CBD) of Nairobi, the capital of Kenya. The settlement is characterized by large-scale 1–3 storey buildings, large blocks, limited public space, and poor public hygiene due to lack of infrastructure. It is located in a hilly terrain to which the street layout adapts in some cases. The informal settlements in Nairobi mostly consist of enclaves with identifiable boundaries. Maxaquene A (referred to as Maxaquene) is located approximately 3 km from the CBD of Maputo, the capital of Mozambique. The urban fabric of Maxaquene is characterised by single-storey detached households, open private space, and large blocks. Its landscape is relatively flat. However, since it is located at a lower altitude compared to the neighbouring areas to the East, it is subject to flooding. Maputo is characterized by a formal urban centre surrounded by a continuous belt of informal urban development, stretching approximately 30 km into the land. 4. Results This section presents the outcomes of the field interviews and provides a summary of the statistics for the eight indicators of urban form along with the observed similarities and differences between the distributions across the five settlements under examination. 4.1. Field Interviews The interview data (Table 1) shows large variations in tenure types, dwelling size, household size, people per room, as well as household access to water and sanitation across the case studies. Access to electricity is high in all case studies. The data shows that residents in settlements with greater percentages of tenants (Antohomadinika, Katanga, and Kibera) have significantly lower access to water and sanitation than residents in settlements with smaller percentages (Hananasif and Maxaquene). Furthermore, the tenants have almost exclusively single-room dwellings while the homeowners have an average dwelling size of 4.48 rooms. While the average household size in Hananasif and Maxaquene is almost double that in Antohomadinika, Katanga and Kibera, households in the latter have almost twice as many people per room. Sample areas with greater percentages of tenants have less access to water and sanitation, along with smaller dwelling size, smaller household size, and more overcrowding. The interview data is based on a relatively limited sample size and findings may thus not be fully representative of the case studies under examination. However, similar statistics were reported for the same settlements in previous studies [25–29].

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Table 1. Interview data for the five settlements under examination.

N. interviewees Tenants (%) Cost of rental household (USD/month) Dwelling size (rooms) Household size (people) People per room (people/rooms) Household access to water (%) Household access to sanitation (%) Household access to electricity (%)

Antohomadinika

Hananasif

Katanga

Kibera

Maxaquene

Average

10 70.00

10 40.00

10 90.00

10 0.00

10 58.00

11.14

17.20

27.12

40.15

23.90

1.60 3.90 2.44 20.00 40.00 90.00

4.40 9.40 2.13 60.00 100.00 90.00

1.10 4.00 3.64 0.00 0.00 80.00

1.30 4.90 3.77 0.00 30.00 90.00

4.40 6.30 1.43 90.00 100.00 90.00

2.56 5.70 2.68 34.00 54.00 88.00

4.2. Settlement Characteristics, Similarities, and Differences The eight indicators of urban form computed for each settlement under examination are summarised in Figure 2. Maps for each indicator and settlement are presented in the Appendix A. Visual inspection of Figure 2 revealed that AND, BS, PrSR seemed to align across settlements. However, FAR, SAV, and AB400 seemed not to. The KS test was used to perform a statistical comparison in a systematic manner across all indicators and settlements (Figure 3). The similarities found were 23 on a total of 80 different combinations, corresponding to a similarity rate of 29%. The strongest pattern of similarity is found for the metric AND. More specifically, all combinations of settlements had statistically similar distribution functions, with most values concentrating approximately 2.6 and 3, that is most intersections surrounding their blocks were bifurcations (i.e., Y- and T-junctions). The only exception is found for the Kibera–Hananasif combination, as their distribution functions, although being generally aligned with the behaviour explained above, diverged sharply, for a smaller number of blocks, at approximately 2.5. The second strongest pattern of similarity involves Antohomadinika, Kibera, and Katanga and is found for the metrics BS, CR, PrSR. Regarding BS, Figure 2 shows that the curves of the distribution functions of the three settlements overlap and peak at approximately 390 m2 , meaning that most of the blocks are relatively small, approximately 1/30 of a manzana (block) in Barcelona, which measures 12,837 m2 [30]. However, since Kibera has some larger blocks, the curve is not as steep as the ones of Antohomadinika and Katanga, thus a statistical similarity is also found with Hananasif, which has blocks measuring approximately 1000 m2 . Maxaquene has much larger blocks on average, measuring approximately 3000 m2 . Regarding CR, most blocks in Antohomadinika, Kibera, and Katanga have a great CR (between 75% and 100%). Most blocks in Hananasif and Maxaquene have a lower CR (66% and 50%, respectively), instead. Concerning PrSR, most blocks in the three high-density settlements have a PrSR of approximately 0.1 (the overall range for this metric is 0–5.78), reflecting denser urban fabrics, with small or no private open space within the blocks. Most blocks in Hananasif and Maxaquene, being less dense, have a lower PrSR (0.5 and 1, respectively). Further similarities are found, however, for fewer combinations of settlements. SAV is similar in Antohomadinika and Kibera, wherein most blocks have a SAV of approximately 1, corresponding to a fairly compact urban fabric (the overall range for this metric is 0.576–1.822). In Katanga and Hananasif, most blocks have a SAV of approximately 1.2, corresponding to a slightly more fragmented urban fabric. However, since Antohomadinika has greater FARs than Kibera, this means that the latter is much more compact. Most blocks in Maxaquene have greater values of FAR (1.3). FAR is similar in Kibera and Katanga, wherein most blocks have a FAR of approximately 1.0. The other three settlements show different distribution functions. Most blocks in Antohomadinika have a greater FAR (1.2), while most blocks in Hananasif and Maxaquene have smaller FARs (0.7 and 0.5, respectively). PuSR is only similar in Kibera and Maxaquene, wherein most blocks have a PuSR of approximately 0.2, corresponding to a scarcity of public space (the overall range for this metric is 0.05–2.90). Hananasif and Katanga, which are more densely built than Maxaquene, have more public space (0.4). This is likely due to the presence of small squares in the urban fabric of both settlements. Most blocks in

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Antohomadinika have small public spaces (0.1). Distribution functions of the metric AB400 are similar only in Antohomadinika and Maxaquene, with most blocks having a value close to 0.1, corresponding to moderate levels of through movement in the street network at the settlement level (the overall range for this metric is 0–0.288). Kibera shows the greatest levels of potential through movement, while Katanga and Hananasif show the smallest levels. This is likely related to different spatial contexts at the edges of the settlements. While Kibera seems to be more integrated into the surrounding street network, Katanga and Hananasif are more inward oriented. The former developed in the interstices of the planned city and has few connections with the surrounding street network. The latter has three on four edges surrounded by wetlands, with only one side connected to the surrounding street network. Urban Sci. 2019, 3, x FOR PEER REVIEW

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Figure 2. Density distribution plots of the eight indicators of urban form for each of the settlements Figure 2. Density distribution plots of the eight indicators of urban form for each of the settlements under examination. Each line corresponds to the value distribution of a specific indicator and under examination. Each line corresponds to the value distribution of a specific indicator and settlement. settlement. Peaks represent where values concentrate over the observed interval. An.: Peaks represent where values concentrate over theHa.: observed interval. An.: Antohomadinika; Ki.: Kibera; Antohomadinika; Ki.: Kibera; Ma.: Maxaquene; Hananasif; Ka.: Katanga. Ma.: Maxaquene; Ha.: Hananasif; Ka.: Katanga.

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Figure 3. 3. Results Resultsof ofthe theKS KStest testperformed performed on on the the distributions distributions of of the the indicators indicators of of urban urban form, form, across across Figure all possible combinations of settlements. Green corresponds to a statistically valid similarity between all possible combinations of settlements. Green corresponds to a statistically valid similarity between the distribution of the indicator across two settlements. Conversely,Conversely, white corresponds the distributionfunctions functions of same the same indicator across two settlements. white to absence oftoa absence statistically similarity. An.: Antohomadinika; Ki.: Kibera; Ma.: Maxaquene; corresponds of avalid statistically valid similarity. An.: Antohomadinika; Ki.: Kibera; Ma.: Ha.: Hananasif; Ka.: Katanga. Maxaquene; Ha.: Hananasif; Ka.: Katanga.

5. Discussion The second strongest pattern of similarity involves Antohomadinika, Kibera, and Katanga and Thefor main the settlements under examination is that their street are is found the commonality metrics BS, CR,ofPrSR. Regarding BS, Figure 2 shows that the curves of thenetworks distribution 2 predominantly characterised by values of AND close to 3, which signifies that most intersections have functions of the three settlements overlap and peak at approximately 390 m , meaning that most of three streets at them, i.e., Y- and T-shaped This is in a feature seenwhich in urban fabrics the blocks areconverging relatively small, approximately 1/30 of ajunctions. manzana (block) Barcelona, measures built through bottom–up approaches, determined the mobility 12,837 m2 [30].self-organised, However, since Kibera has some larger blocks, theby curve is not asneeds steep of as pedestrians. the ones of Previous studies and [31,32] found that emergence of street organised through YAntohomadinika Katanga, thus the a statistical similarity is networks also foundmainly with Hananasif, which has 2. Maxaquene and T-shaped junctions is related 1000 to themmovement of pedestrians between different places measuring of interests blocks measuring approximately has much larger blocks on average, 2 (e.g., schools, places of worship, and markets). Ribeiro [31] also suggests that while the first approximately 3000 m . Regarding CR, most blocks in Antohomadinika, Kibera, and Katanga type haveof a junction generally associated with the diverging or converging to a place of have interest and thus with great CR is (between 75% and 100%). Most blocks in Hananasif and Maxaquene a lower CR (66% flow50%, in the street network, the second type marks connection a more residentialsettlements circulation and respectively), instead. Concerning PrSR, the most blocks in with the three high-density system (e.g., dead-end streets). have a PrSR of approximately 0.1 (the overall range for this metric is 0–5.78), reflecting denser urban Thiswith study identified settlements withwithin comparable featuresMost (Antohomadinika, Kibera, and and fabrics, small or no three private open space the blocks. blocks in Hananasif Katanga) andbeing two settlements (Hananasif and Maxaquene) are not only different from the former Maxaquene, less dense, have a lower PrSR (0.5 and 1,that respectively). group but also from eachare other. More specifically, Antohomadinika, Kibera, and Katanga Further similarities found, however, for fewer combinations of settlements. SAVare is densely similar 2 built, with relativelyand small blocks (approximately 390 m ),a high coverage ratios (between 75% and in Antohomadinika Kibera, wherein most blocks have SAV of approximately 1, corresponding 100%), andcompact small private blocksrange (0.1 infor a range 0–5.78).is The built-up densities are and also to a fairly urbanspaces fabricwithin (the overall this metric 0.576–1.822). In Katanga comparablemost as most blocks havea FARs 1 and 1.2. We that theretoarea several Hananasif, blocks have SAV between of approximately 1.2,suggest corresponding slightlyreasons more behind theseurban densefabric. urbanHowever, fabrics. since Antohomadinika has greater FARs than Kibera, this means fragmented Angel [33]isargues greenbelt policies of affordable to containment of that the latter much that more compact. Most increase blocks incosts Maxaquene havehousing greaterdue values of FAR (1.3). urbanisexpansion consequent decreased land supply, resulting competition and higher FAR similar inand Kibera and Katanga, wherein most blocks haveinaincreased FAR of approximately 1.0. The prices.three A similar tendency condition accommodation the informal settlements under other settlements showmay different distribution functions.costs Mostinblocks in Antohomadinika have the while informal land supply is constrained through government restrictions aexamination. greater FAR If (1.2), most blocks in Hananasif and Maxaquene have smaller FARs (0.7(see and[34]), 0.5, less informal land leading to increased competitionwherein and higher prices. Conversely, when respectively). PuSRisisavailable, only similar in Kibera and Maxaquene, most blocks have a PuSR of governments adopt less stringent policies towards informal urban development, informal land supply approximately 0.2, corresponding to a scarcity of public space (the overall range for this metric is is less restricted, leading less competition lower prices (see [35]). As the urban are 0.05–2.90). Hananasif and to Katanga, which areand more densely built than Maxaquene, havemajorities more public financially fromdue thetoformal land market [1],squares the extent of the informal supply and size space (0.4). excluded This is likely the presence of small in the urban fabricland of both settlements. of theblocks urban in poor population likely determine the population of informal settlements. We Most Antohomadinika have small public spaces (0.1).densities Distribution functions of the metric thus suggest that aonly smaller supply of informal is one ofwith the likely of the high densities AB400 are similar in Antohomadinika andland Maxaquene, most causes blocks having a value close thatathigher housing found in Antohomadinika, Kibera, and of Katanga. & Gottlieb [36] argue to 0.1, corresponding to moderate levels throughGlaeser movement in the street network the settlement prices(the do not necessarily to anis increase in national wealth, the since the values have offset level overall range correspond for this metric 0–0.288). Kibera shows greatest levels ofbeen potential through movement, while Katanga and Hananasif show the smallest levels. This is likely related to different spatial contexts at the edges of the settlements. While Kibera seems to be more integrated 126

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by the higher costs for securing a basic necessity. Accordingly, increased competition in the informal land market is likely related to higher rents and thus to fewer household resources for investments in infrastructure. This, in turn, leads to increased overcrowding, substandard housing, and decreased access to water and sanitation. The household survey data and the outcomes of the quantitative analysis highlight that areas with high urban densities also have greater proportions of tenants, more overcrowding, and lower levels of access to water and sanitation. However, the relation between property prices, location, and urban density of informal settlements in Sub-Saharan Africa remains under-researched [37]. Accordingly, further studies are needed to validate the hypotheses formulated in this paper. Distance to CBD might further explain the high densities in Antohomadinika, Kibera, and Katanga. Generally, built densities are highest in the CBD and decrease as a function of distance and transportation costs [38]. Peripheral areas thus tend to have lower land prices and higher transportation costs, which induce lower densities. Conversely, more central areas tend to have higher land prices and lower transportation costs, which result in higher densities. However, this seems to hold only for Antohomadinika and Katanga (i.e., 1 km and 2 km away from the CBD, respectively), but not for Kibera, which is located 5 km away from the CBD. We suggest that, since Kibera was established at the beginning of the 20th century [39], it might have consolidated and developed the characteristics of a subcentre (e.g., higher employment densities, better connectivity to the metropolitan system) over time, thus attracting speculative housing market practices similar to that of more centrally located settlements. Indeed, Kibera’s street network has the most through movement among the case studies considered, a plausible sign of its integration with the surrounding neighbourhoods. A further possible reason for the misalignment of Kibera might be associated with the existence of two parallel land markets. As built densities are not only determined by the transportation costs to reach the CBD, but also determined by the volume of informal land in the city and its relative centrality within the informal land market, formal and informal neighbourhoods with comparable centrality might display large variations in built densities (e.g., dense informal settlements next to suburban neighbourhoods). Consequently, although Kibera is at a considerable distance from the CBD, it might be centrally located within the informal land market and transportation costs to the CBD may be relatively low compared to other informal settlements in the city. Our analysis also highlights that Hananasif and Katanga, which are more densely built than Maxaquene, have more public space than the latter, in the form of larger streets and squares. In Hananasif, this is the effect of local governance practices and a slum upgrading project which expanded the streets and nearby open areas [28]. In Katanga, the presence of more public spaces is probably not the outcome of local governance but rather the effect of a canal passing through the settlement, which stopped urbanisation from happening on its banks and immediate surroundings due to yielding ground. The small blocks in this settlement (i.e., most of them measure approximately 219 m2) might have also required more public space for basic accessibility. This outcome shows that quantifying open space through two sperate indicators (i.e., PrSR and PuSR) can be advantageous for obtaining information that could eventually guide interventions in two realms with different levels of operational restriction. The three case studies with high built densities show larger shares of tenants as well as overcrowding, and inadequate access to water and sanitation. We suggest that government control of the land market limits the informal land supply affordable for the urban poor majorities and leads to the increased price of informal land. Consequently, residents pay higher rents, leading to fewer resources for investments in infrastructures and consequent proliferation of the three UN-defined slum characteristics mentioned above. This is a notable finding, as it suggests that the rule of law, in this particular case, leads to increasingly compromised livelihoods. Less stringent rules on informal land together with infrastructure investment could be a way forward for improving living conditions in informal settlements. The proposed methodology overcomes limitations of previous ad-hoc qualitative assessments, for example [8,9], as it is based on a set of systematic steps and focuses on blocks rather than entire

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settlements. It also provides advantages over existing quantitative methodologies, for example [10,11], as it describes the urban form of informal settlements through a comprehensive set of indicators, measuring aspects of the urban fabric and configuration of the street network, the scale of which permits replicability. The application presented in this paper shows that outcomes are detailed and varied, i.e., through interview data (Table 1), maps of the indicators (Appendix A), density plots (Figure 2), and similarity matrices (Figure 3), thus providing a solid basis for the interpretation of local dynamics that affect the development and form of informal settlements and the eventual proposal of design strategies aimed at their upgrading. The main challenges of the proposed methodology involve carrying out field surveys, as they can be costly and time consuming, as well as organising and interpreting the detailed outputs. 6. Conclusions The scarcity of studies on the morphology of informal settlements at a fine level of spatial granularity limits knowledge on the formation and development of such areas as well as the capacity to develop effective policy and urban planning in this context. In this paper, we present a morphological analysis at the block level of five informal settlements in East Africa (Antohomadinika, Kibera, Katanga, Hananasif, and Maxaquene). Outcomes show the emergence of a general pattern across the settlements, i.e., street networks are characterised by organic layouts based on bifurcations (i.e., Y- and T-junctions), a feature found in self-organised/bottom–up settlements. Furthermore, most blocks in Antohomadinika, Kibera, and Katanga were found to be densely built with limited open space. We suggest that this was due to stronger forms of control of the informal land market, speculative housing markets and the relative distance to the CBD. Hananasif and Maxaquene were not only found to be statistically different from the above-mentioned group of settlements, but also to each other. More precisely, most blocks in Hananasif were slightly denser than the blocks in Maxaquene. Counterintuitively, although Hananasif possessed these features, it had more public space than Maxaquene. This was suggested to be the result of local administration practices and a slum upgrading initiative aimed at enlarging the streets of the settlement. The proposed methodology overcomes limitations of previous works, especially concerning replicability, scale, and robustness. It can be applied to further cases to gain a better understanding of local features of informal settlements and eventually guide ad-hoc strategies, which could deliver more effective urban planning and policies. We argue that limited informal land supply, partly caused by government control of the land market, leads to higher costs of accommodation and consequently fewer resources for private investments in infrastructures and home improvements. This, in turn, leads to proliferation of slum conditions in informal settlements, such as overcrowding and inadequate access to water and sanitation. We thus argue that accepting some modes of informal urban development will likely improve living conditions, as it would increase the informal land supply and thereby decrease the price of accommodation and free resources for investments in basic infrastructures. On this basis, we argue that governments should rather focus on guiding developments of informal settlements and invest in infrastructures rather than evicting them. This could be pioneered through state-financed allocation of small plots with leasehold titles on government-owned land, with allocation of sufficient street space, common water and sanitation units, and local guidance for autoconstruction without enforcement of the building code. This study suggests that this will be a viable path towards improved living conditions for the urban poor majorities in East African cities. Author Contributions: J.M.: conceptualisation, methodology, software, data curation, writing—original draft preparation, visualisation, investigation, and writing—reviewing and editing. A.V.: conceptualisation, methodology, software, data curation, writing—original draft preparation, visualisation, investigation, and writing—reviewing and editing. All authors have read and agreed to the published version of the manuscript. Funding: This study was funded by The Danish Council of Independent Research (ID: 7023-00007B), KADK—The Royal Danish Academy of Fine Arts School of Architecture. It was also supported by the French government, through the UCA JEDI Investments in the Future project managed by the National Research Agency (ANR) with the reference number ANR-15-IDEX-01.

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Acknowledgments: We would like to thank the municipality and local authorities in the five settlements studied in this paper for permitting the spatial surveys as well as the members of the communities of each settlement who participated in the field interviews. Finally, we would like to thank the following residents who facilitated the field work: Mario Mugano Xikumbane, Ali Muhammed Muhina, Ally Hassan Ally, Daniel Futwax, John Saturday Bwambale, David Esenga, Kyeyune Daniel, Vero Razafinirina, Ravaonirina Andrine, Rasoanirina Zoeline, and Rabevaza Selestin. Urban Sci. 3, x FORThe PEER REVIEW Conflicts of2019, Interest: authors declare no conflict of interest.

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AppendixAA Appendix

FigureA1. A1. Maps Maps of forfor thethe fivefive informal settlements underunder examination. Figure ofblock blocksize size(BS) (BS) informal settlements examination.

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Figure A2.A2. Maps of coverage ratio (CR) forfor thethe fivefive informal settlements under examination. Figure Maps of coverage ratio (CR) informal settlements under examination.

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Figure Maps of floor ratio (FAR) informal settlements under examination. Figure A3.A3. Maps of floor areaarea ratio (FAR) for for thethe fivefive informal settlements under examination.

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Figure Mapsofofsurface surface area ratio (SAV) for the settlements under examination. Figure A4.A4. Maps areatotovolume volume ratio (SAV) forfive theinformal five informal settlements under examination.

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Figure A5. Maps average node degree (AND) informal settlements under examination. Figure A5. Maps of of average node degree (AND) forfor thethe fivefive informal settlements under examination.

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Figure Maps of average betweenness m (AB400) five informal settlements Figure A6.A6. Maps of average betweenness at 400atm 400 (AB400) for the for five the informal settlements under under examination. examination.

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Figure A7.A7. Maps of private space ratio (PrSR) for for the the fivefive informal settlements under examination. Figure Maps of private space ratio (PrSR) informal settlements under examination.

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Figure A8.A8. Maps of public space ratio (PuSR) for for thethe fivefive informal settlements under examination. Figure Maps of public space ratio (PuSR) informal settlements under examination.

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UN-Habitat. State of the World’s Cities 2012/2013: Prosperity of Cities; Routledge: New York, NY, USA, 2013. Jenkins, P. Urbanization, Urbanism, and Urbanity in an African City: Home Spaces and House Cultures; Palgrave Macmillan: New York, NY, USA, 2013. UN-Habitat. Slums of the World: The Face of Urban Poverty in the New Millennium; UN-Habitat: Nairobi, Kenya, 2003. Moudon, A.V. Urban morphology as an emerging interdisciplinary field. Urban Morphol. 1997, 1, 3–10. Frank, L.; Engelke, P.; Engelke, S.F.P.; Schmid, T. Health and Community Design: The Impact of the Built Environment on Physical Activity; Island Press: Washington, DC, USA, 2003. Liu, C.; Shen, Q. An empirical analysis of the influence of urban form on household travel and energy consumption. Comput. Environ. Urban Syst. 2011, 35, 347–357. [CrossRef] Venerandi, A. A Quantitative Method to Study the Relationship between Urban Form and City Liveability Indexes. Ph.D. Thesis, UCL (University College London), London, UK, 2017. Available online: https: //discovery.ucl.ac.uk/id/eprint/1569319/ (accessed on 20 June 2020). Davis, M. Planet of Slums; Verso: London, UK, 2006. Dovey, K.; King, R. Forms of informality: Morphology and visibility of informal settlements. Built Environ. 2011, 37, 11–29. [CrossRef] Iovene, M.; Fernández de Córdova, G.; Romice, O.; Porta, S. Towards Informal Planning: Mapping the Evolution of Spontaneous Settlements in Time. In Proceedings of the 24th ISUF International Conference, València, Spain, 27–29 September 2017. Hillier, B.; Greene, M.; Desyllas, J. Self-generated Neighbourhoods: The role of urban form in the consolidation of informal settlements. Urban Des. Int. 2000, 5, 61–96. [CrossRef] Fleischmann, M. Momepy: Urban morphology measuring toolkit. J. Open Source Softw. 2019, 4, 1807. [CrossRef] Ratti, C.; Baker, N.; Steemers, K. Energy consumption and urban texture. Energy Build. 2005, 37, 762–776. [CrossRef] Opsahl, T.; Agneessens, F.; Skvoretz, J. Node centrality in weighted networks: Generalizing degree and shortest paths. Soc. Netw. 2010, 32, 245–251. [CrossRef] Lü, L.; Zhou, T.; Zhang, Q.M.; Stanley, H.E. The H-index of a network node and its relation to degree and coreness. Nat. Commun. 2016, 7, 10168. [CrossRef] Porta, S.; Latora, V.; Wang, F.; Rueda, S.; Strano, E.; Scellato, S.; Cardillo, A.; Belli, E.; Cardenas, F.; Cormenzana, B.; et al. Street centrality and the location of economic activities in Barcelona. Urban Studies 2012, 49, 1471–1488. [CrossRef] Wang, F.; Antipova, A.; Porta, S. Street centrality and land use intensity in Baton Rouge, Louisiana. J. Transp. Geogr. 2011, 19, 285–293. [CrossRef] Remali, A.M.; Porta, S.; Romice, O.; Abudib, H.; Vaughan, L. Street quality, street life, street centrality. In Suburban Urbanities: Suburbs and the Life of the High Street; UCL Press: London, UK, 2015; pp. 104–129. Porta, S.; Crucitti, P.; Latora, V. The network analysis of urban streets: A primal approach. Environ. Plan. B Plan. Des. 2006, 33, 705–725. [CrossRef] Mehaffy, M.; Porta, S.; Rofe, Y.; Salingaros, N. Urban nuclei and the geometry of streets: The ‘emergent neighborhoods’ model. Urban Des. Int. 2010, 15, 22–46. [CrossRef] Berghauser-Pont, M.Y.; Haupt, P. Spacematrix: Space, Density and Urban Form; NAi Publishers: Rotterdam, The Netherlands, 2010; pp. 297–298. Hastie, T.; Tibshirani, R.; Friedman, J. The Elements of Statistical Learning: Data Mining, Inference, and Prediction; Springer Science & Business Media: New York, NY, USA, 2009. Conover, W.J. Practical Nonparametric Statistics; John Wiley & Sons: New York, NY, USA, 1971. Desgroppes, A.; Taupin, S. Kibera: The biggest slum in Africa? Les Cahiers d’Afrique de l’Est/East Afr. Rev. 2011, 44, 23–33. Laureau, C.; Blanchard, C.; Godinot, X. Making Health Services Work for Poor People: Ten Years of Work in Tananarive, Madagascar. World Bank Work. Pap. 2006, 77, 37. African Population and Health Research Center (APHRC). Population and Health Dynamics in Nairobi’s Informal Settlements: Report of the Nairobi Cross-Sectional Slums Survey (NCSS) 2012; APHRC: Nairobi, Kenya, 2014.

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Raimundo, J.A.; Raimundo, I.N. Operation of the Market Study: Land Access in Urban Areas, the Case of Maputo; Urban LandMark: Pretoria, South Africa, 2012. Precht, R. Informal settlement upgrading and low-income rental housing: Impact and untapped potentials of a community-based upgrading project in Dar Es Salaam Tanzania. In Proceedings of the 3rd World Bank Urban Research Symposium on Land Development, Urban Policy and Poverty Reduction, Brasilia, Brazil, 4–6 April 2005. Mbiggo, I.; Ssemwogerere, K. An Investigation into Fire Safety Measures in Kampala Slums—A Case of Katanga-Wandegeya. Civ. Environ. Res. 2018, 10, 30–34. Aibar, E.; Bijker, W.E. Constructing a city: The Cerdà plan for the extension of Barcelona. Sci. Technol. Hum. Values 1997, 22, 3–30. [CrossRef] Ribeiro, G. An ecological approach to the study of urban spaces: The case of a shantytown in Brasilia. J. Archit. Plan. Res. 1997, 14, 289–300. Hamouche, M.B. Can chaos theory explain complexity in urban fabric? Applications in traditional Muslim settlements. In Nexus Network Journal; Birkhäuser: Basel, Switzerland, 2009; pp. 217–242. Angel, S. Housing Policy Matters: A Global Analysis; Oxford University Press: Oxford, UK, 2000; pp. 31–33. Talukdar, D. Cost of being a slum dweller in Nairobi: Living under dismal conditions but still paying a housing rent premium. World Dev. 2018, 109, 42–56. [CrossRef] Jenkins, P. Emerging Land Markets for Housing in Mozambique: The Impact on the Poor and Alternatives to Improve Land Access and Urban Development—An Action Research Project in Peri-Urban Maputo; Research Paper; Edinburgh College of Art/Heriot-Watt University, School of Planning & Housing: Edinburgh, UK, 2001; Volume 75. Glaeser, E.L.; Gottlieb, J.D. The wealth of cities: Agglomeration economies and spatial equilibrium in the United States. J. Econ. Lit. 2009, 47, 983–1028. [CrossRef] Visagie, J.; Turok, I. Getting urban density to work in informal settlements in Africa. Environ. Urban. 2020, 21, 309–329. [CrossRef] Bertaud, A. Order without Design: How Markets Shape Cities; MIT Press: Cambridge, MA, USA, 2018; pp. 143–219. De Smedt, J. “Kill Me Quick”: A History of Nubian Gin in Kibera. Int. J. Afr. Hist. Stud. 2009, 42, 201–220. © 2020 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).

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Double corridor housing Drops of water fall through the open ceiling and splash on the ground in the dark corridor. The upstairs neighbors are busy hanging up the daily laundry of the limited wardrobe. The central corridor provides access to two rows of single-room rental apartments without windows. A shared space by the end of the corridor provides access to the upper floor as well as a common water tap and latrine facility for more than 50 dwellings. A resident explains that ‘Chocolate city’ is the neighborhood epithet and a poetic allusion of the mud and rusty iron sheet clad eucalyptus log structures they refer to as ‘home’ while landlords residing far from the soggy streets of Kibera cash-in at the start of each month.

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A TAXONOMY OF INFORMALITY: EXPLORING BLOCK TYPES IN FIVE INFORMAL SETTLEMENTS IN EAST AFRICA Alessandro Venerandi, ESPACE, University of Cote d’Azur, Nice, France Johan Mottelson, Institute of Architecture, Urbanism and Landscape, KADK - The Royal Danish Academy of Fine Arts - Schools of Architecture, Design and Conservation, Copenhagen, Denmark

ABSTRACT Approximately 13% of the world population lives in informal settlements, characterized by limited state control, inadequate infrastructure provision, and lack of planning. While the relevance of studies of informal settlements is widely acknowledged, the urban morphology of such areas is understudied, compromising the development of effective planning and policy targeting such areas. In this paper, we present a taxonomic study at a fine level of spatial granularity of the urban form of five informal settlements, located in major cities of Sub-Saharan Africa. More specifically, a k-means clustering is applied to eight indicators of urban form computed at block level, for each of the settlements under examination. The best clustering identified seven different block types associated with distinctive features, such as blocks on public spaces (small, densely built, abundant public open space), fringe blocks (medium-sized, sparsely built, low local connectivity), blocks in the making (large, sparsely built, high levels of through movement at settlement level). We argue that this taxonomy provides detailed information about the case studies under examination, which can potentially inform design strategies aimed at their upgrading. Finally, it presents some of the first attempts at establishing replicable quantitative data driven descriptions of the urban form of informal settlements. Keywords: informal settlements, taxonomy, urban form, k-means clustering, East Africa. INTRODUCTION Informal settlements are urban areas typified by lack of state control built on a land which the occupants have no legal claim to, or areas where construction is not in compliance with current planning and building regulations (Jenkins, 2006; OECD, 2001). These settlements are often characterized by insecure tenure, overcrowding, substandard housing, and inadequate access to water and sanitation (UN-Habitat, 2003). It is estimated that at least one in eight people (roughly one billion dwellers) live in informal settlements worldwide (UN-Habitat, 2015). In Sub-Saharan Africa, the urban majority resides in informal settlements, and the likelihood of continued high population growth, rural to urban migration, and limited state capacity to accommodate the growing urban population will likely lead to a continued proliferation of informal urban development in the coming decades (UNHabitat, 2013). While the relevance of studies of informal settlements is widely recognized, their urban form remains understudied, compromising urban planning and policies aimed at improving such settlements (Visagie & Turok 2020). A taxonomy of urban types based on similarities and differences can provide a more thorough understanding of the development and urban form of informal settlements. Its main advantage lies in its heuristic value as it can structure detailed and complex information in order to reach generalizability (Rapoport, 1990). However, the level of detail, robustness, and generalizability of the outcomes largely depend on the approach utilized and the spatial granularity of the data in input. Existing taxonomies of informal settlements are largely obtained through approaches based on qualitative assessments and mainly focus on entire settlements or on very small fragments. Davis (2006), for example, developed a taxonomy of slum typologies based on his observations of locational factors, formal/informal features, and tenure status. Dovey and King (2011) defined classification of informal settlements by interpreting their processes of growth in terms of settling, inserting, and attaching. Similarly, Del Bianco (2014) proposed a classification of housing types in a block of an informal settlement in Sao Paulo, Brazil, based on interpretations of a field survey. Although these works provide valuable insights into several aspects of settlements and their relation with surrounding contexts, they do not describe the urban form at a fine level of spatial granularity. Furthermore, being based on qualitative assessments, they are hardly replicable thus limiting our knowledge of informal 142

urban development. This paper presents a taxonomy of blocks based on a replicable technique (i.e., k-means clustering) and fine-grained data obtained from high resolution orthophotos and GPS traces to address the following research question: what are the typical urban form features of blocks in informal settlements in East Africa? METHODOLOGY The methodology implemented to answer this research question relies on three subsequent steps: (i) collection and processing of spatial data for the five settlements under examination; (ii) computation of eight indicators of urban form at the block level; and (iii) application of a clustering technique to these indicators to obtain block types. We present these steps in more detail next. COLLECTION AND PROCESSING OF SPATIAL DATA Data at a fine level of spatial granularity for the five settlements under examination were collected with an unmanned aerial vehicle (drone) and a handheld GPS-device (smartphone). The former was used to obtain high-resolution aerial imagery which was then processed with Pix4D 1 to generate georeferenced orthophotos, Digital Surface Models (DSMs), and 3D models. The latter was used to map the street networks of the settlements under examination through SW Maps. 2 Streets were recorded by walking along the boundaries of every block in each settlement. Georeferenced orthophotos and GPS traces were then imported in a GIS software, automatically scaled, and exported in a design software application. Buildings were then traced manually based on the orthophotos. Multi-storey buildings were identified through DSMs and 3D models and separate layers were created for each floor. Finally, street networks and blocks were manually drawn based on both GPS traces and orthophotos. Buildings, blocks, and street networks in vector format were utilized for carrying out the analysis presented in this paper. INDICATORS OF URBAN FORM Eight urban form indicators were used to characterize the five settlements under examination at the block level. Six indicators measure aspects of the urban fabric. Two indicators quantify features of the configuration of the street network. The former include: • • • •

•

Block Size (BS), which measures the block area in square meters; Coverage Ratio (CR), which quantifies the percentage of land occupied by buildings; Floor Area Ratio (FAR), which measures the built-up density. It is computed by summing the Gross Floor Areas (GFAs) of the buildings in a block and dividing such value by BS; Surface Area to Volume Ratio (SAV), which represents the levels of fragmentation of the building envelopes. SAV is calculated by multiplying the perimeters of the buildings in a block by their heights, summing this value to two times the sum of the building footprints in each block, and by dividing this value by the built-up volume in each block; Private Space Ratio (PrSR), which quantifies the amount of private open space relative to the built-up density. It is computed by subtracting the building footprints from BS and dividing this value by the Gross Floor Areas (GFAs) 3 of the buildings in a block; Public Space Ratio (PuSR), which measures the amount of public open space relative to the built-up density. The area of public open space in a block is obtained by subtracting BS from the area of the polygon created by the road center lines surrounding a block. PuSR is then computed by dividing such value by the Gross Floor Areas (GFAs) of the buildings in a block; Average Node Degree (AND), which measures the level of block connectivity. It is computed by averaging the node degrees associated with the street intersections surrounding a block;

Pix4D is a photogrammetry software available at https://www.pix4d.com SW Maps is an app that records GPS traces and is available at http://swmaps.softwel.com.np/# 3 GFA is obtained by multiplying the building footprint by the number of floors. 1 2

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•

Average Betweenness at 400m (AB400), which quantifies the average levels of through movement on the edges of a block. The formula for computing betweenness centrality can be found in the work by Porta et al. (2006). Since the settlements under examination had sizes comparable to that of city neighborhoods, we computed betweenness centrality at 400m radius, a measure commonly associated with the neighborhood scale (Mehaffy et al., 2010). Finally, each block was assigned with the average value of betweenness centrality associated with its surrounding streets.

PrSR and PuSR are variations of Open Space Ratio (OSR) proposed by Berghauser-Pont and Haupt (2010). The advantage of using these indicators is that they distinguish between private and public open spaces. AND and AB400 were computed by adapting scripts contained in momepy, a Python library for the quantitative analysis of urban form (Fleischmann, 2019). CLUSTERING THE INDICATORS The k-means clustering was applied to the values of the indicators presented above to obtain a block taxonomy for the informal settlements under examination. K-means is a data mining technique to partition a large number of observations into a small set of representative clusters in which each observation belongs to the cluster with the nearest mean (cluster centroid) (Forgy, 1965). These centroids are selected by minimizing the within-clusters sum-of-squares (WCSS), a measure of variability of observations within each cluster. Since k-means uses distance-based measurements to determine similarities between observations and our indicators have different units of measurement, we standardized the data to have a mean of 0 and a standard deviation of 1. Since k-means requires the number of clusters to be defined, we tested different numbers and used the elbow method to determine the optimal solution. The latter is a heuristic technique consisting in plotting the WCSS as a function of the number of clusters and choosing the sharpest bend of the curve as the number of clusters to use (Thorndike, 1953). Finally, to avoid the overrepresentation of certain aspects of urban form due to a disproportion in terms of number of observations (blocks) across the settlements, a weighting system was applied to the k-means clustering to account for the number of blocks in each settlement. More specifically, weights for the observations in a specific settlement were computed by dividing the number of blocks in the smallest settlement by the total number of blocks in such settlement. CASE STUDIES The methodology presented above was applied to build a block taxonomy of five informal settlements in East Africa. We present processed orthophotos and vectoral maps for each settlement in Figure 1 and brief descriptions next: •

•

Kibera is the biggest informal settlement in Africa (Desgroppes & Taupin, 2011). It is located approximately 5 km from the Central Business District (CBD) of Nairobi, the capital of Kenya, and is characterized by large blocks, small public spaces, large-scale buildings of 1 to 3 floors, and poor public hygiene due to lack of infrastructure. Antohomadinika is located approximately 1 km from the CBD of Antananarivo, the capital of Madagascar, and is characterized by multi-storey buildings, high ground occupation, small public space, and poor public hygiene due to frequent flooding. Maxaquene is located approximately 3 km from the CBD of Maputo, the capital of Mozambique. The urban fabric of this settlement is mainly characterized by large blocks, single-storey detached buildings, and large open private spaces. Katanga is located approximately 2 km from the CBD of Kampala, the capital of Uganda. It is located near the main city hospital and occupies an interstitial space in the formal urban fabric. The settlement is mainly characterized by dense single-storey buildings, parking areas, and a large soccer field.

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•

Hananasif is located approximately 3 km from the CBD of Dar es Salaam, the biggest city in Tanzania. The settlement is characterized by single-storey detached buildings and relatively wide streets, which allow car access.

Figure 1. Orthophotos and vectoral maps of the five settlements under examination.

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A BLOCK TAXONOMY After having computed and standardized the values of the indicators of urban form across all settlements, we computed weights to assign to each observation with the method described in Clustering the indicators. By doing so, the observations in Kibera were assigned 0.67; the ones in Antohomadinika 0.90; the ones in Maxaquene 1.00; the ones in Katanga 0.28; the ones in Hananasif 0.27. The k-means technique was then implemented with these weights and for solutions from 2 to 20 clusters. The plot in Figure 2 was then used to detect the sharpest bend of the function and the optimal number of clusters/block types (i.e., 10). In Figure 3, we present maps for each of the settlements under examination with blocks color-coded according to their types. To understand the typical features of each block type, we computed the average values of the indicators of urban form for the blocks pertaining to each cluster/type and compared such values to quartiles computed across all settlements (Table 1). We present 3D representation of each block type in Figure 4 and brief descriptions based on this data next: •

•

Connected blocks (type 0 and 7). These tend to be small, densely built, with small private and public open spaces, compact, averagely connected at the local level, with high levels of through movement at settlement level. These are mainly located in Kibera and Antohomadinika in both central and peripheral parts that are very well connected across scales. Due to their small size, we suggest that some of these blocks may be merged without compromising mobility in the settlement in order to increase private and public open space. Type 0 and 7 were merged into the same category because only 2 indicators (i.e., FAR, PrSR) on 8 had significantly different values. Balanced blocks (type 1). These are medium-sized, moderately dense, with mid-sized open private and public spaces, averagely compact, with medium levels of connectivity at the local level and through-movement at settlement level. These blocks are located in central and peripheral parts of the settlements under examination, but mostly in Hananasif. Blocks in the making (type 2 and 4). These tend to be large, characterized by low densities, large private open spaces, medium-sized to large public open spaces, fragmented building layouts, averagely connected at block level, with low to moderately high through movement at settlement level. They are mainly located in Maxaquene and at the periphery of Katanga. We labeled such blocks “in the making'' as their features suggest that they were only recently established and will probably undergo processes of densification and subdivision. Type 2 and 4 were put in the same category because only 2 indicators on 8 (i.e., PuSR, AB400) showed significantly different values. Blocks on public spaces (type 3). These are very small, characterized by high densities, small private open spaces, very large public open spaces, very fragmented building layouts, very well connected at the local level, but with poor through movement at settlement level. These blocks are mainly located in Katanga and Hananasif near squares of different sizes and canal banks. Secluded blocks (type 5). These are small, very dense, with small private and public open spaces, averagely compact, averagely connected at the block level, but poorly at the settlement level. These blocks can be found across all settlements but most of them are in Katanga. They tend to be located in more segregated/enclosed spaces with poor through movement at settlement level. Fringe blocks (type 6). These are medium-sized, characterized by a relatively low built-up density, abundant private open space, medium-sized open public spaces, moderately fragmented building layouts, and low local connectivity and through movement at settlement level. By inspecting Figure 3, we observe that these blocks are indeed located at the peripheries of the settlements under examination and face natural or artificial barriers, such as wetlands, canals, or major roads. Furthermore, since settlements tend not to have access for cars, some of these blocks are used for parking by residents or people working locally. Blocks with potential (type 8 and 9). These are large to very large, characterized by average densities, mid-sized open private spaces, relatively compact building layouts, small public open spaces, low local connectivity, and high levels of through movement at the settlement

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level. Due to their large size, above average number of dead end streets, and presence of unbuilt spaces, we suggest that these blocks hold the potential for being subdivided to increase accessibility and enlarge public open spaces, which, in turn, might favor new commercial and recreational activities at the street level. Type 8 and 9 were merged into the same category because only FAR had significantly different values.

Figure 2. Optimal number of clusters/block types. cluster/block type

no. of blocks

FAR

PrSR

PuSR

SAV

AND

AB400

417

1.49

0.056

0.178

0.930

2.859

0.109

105

1276

0.69

0.471

0.435

1.150

2.983

0.079

2966

0.47

1.168

0.313

1.304

2.850

0.104

0.93

0.100

1.576

1.437

2.945

0.053

1578

0.20

4.223

1.170

1.181

2.786

0.023

115

263

0.94

0.093

0.411

1.168

2.794

0.052

1020

0.54

0.912

0.440

1.206

2.232

0.056

679

0.91

0.145

0.349

1.074

2.799

0.171

4574

0.93

0.287

0.146

1.023

2.624

0.115

15436

0.79

0.319

0.140

1.013

2.552

0.155

Min

0.15

0.000

0.054

0.576

1.667

0.000

1st Qu.

201

0.64

0.088

0.234

1.075

2.581

0.043

Mean

1308

0.81

0.435

0.438

1.162

2.778

0.080

3rd Qu.

1544

0.97

0.563

0.499

1.228

3.000

0.107

Max

19554

100

2.00

5.776

2.896

1.822

3.333

0.288

quartiles across all case studies

Table 1. Average values of the indicators of urban form for each block type and quartiles across all settlements.

CONCLUSIONS Taxonomies of different urban types in informal settlements have been proposed by several scholars. However, these were largely based on qualitative evaluations and mainly focused on entire settlements or on very small parts. The difficulty of replicating these works and the uneven levels of spatial information limit our knowledge of informal urban development. In this paper, we presented a 6 ISUF 2020 Cities in the Twenty-first Century 147

block taxonomy of five informal settlements in Sub-Saharan Africa based on a replicable technique (weighted k-means) and indicators of urban form at the block scale. Outcomes suggest the existence of 10 different block types associated with distinctive traits, positional factors, and different levels of development. While these findings may not cover all block types in informal settlements due to the limited number of cases, the taxonomy presents one of the first attempts to develop more generalizable quantitative descriptions of the urban form of such areas. In fact, the methodology presented in this paper is replicable. Accordingly, further analyses of informal settlements can be carried out to confirm, amend, or reject the block types found in this work and thereby improve our understanding of informal urban development.

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Figure 3. Settlements under examination with blocks color-coded according to their types.

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Figure 4. Examples of block types.

REFERENCES Berghauser-Pont, M. Y., & Haupt, P. (2010). Spacematrix: space, density and urban form (NAi Publishers, Rotterdam). 9 ISUF 2020 Cities in the Twenty-first Century

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Davis, M. (2006). Planet of Slums (Verso, London). Del Bianco, C. (2014). Surveying Informal Settlements: The São Paulo Case Study of Jardim Filhos da Terra. International Journal of Anthropology 29. Desgroppes, A., & Taupin, S. (2011). Kibera: The biggest slum in Africa?. Les Cahiers d’Afrique de l’Est/The East African Review 44, 23-33. Dovey, K., & King, R. (2011). Forms of informality: Morphology and visibility of informal settlements. Built Environment 37(1), 11-29. Fleischmann, M. (2019). momepy: Urban morphology measuring toolkit. Journal of Open Source Software 4(43), 1807. Forgy, E. W. (1965). Cluster analysis of multivariate data: efficiency versus interpretability of classifications. Biometrics 21, 768-769. Jenkins, P., 2006, Informal Settlements: Infernal and Eternal? The role of research in policy advocacy and urban informal settlements in Angola, in (eds.) Huchzermeyer, M., Karam, A., Informal Settlements: A Perpetual Challenge? (University of Cape Town Press, Cape Town). Mehaffy, M., Porta, S., Rofe, Y., & Salingaros, N. (2010). Urban nuclei and the geometry of streets: The ‘emergent neighborhoods’ model. Urban Design International 15(1), 22-46. OECD (Organisation for Economic Co-operation and Development) (2001). Glossary of Statistical Terms. Technical Report. Porta, S., Crucitti, P., & Latora, V. (2006) The network analysis of urban streets: a primal approach. Environment and Planning B: planning and design 33(5), 705-725. Rapoport, A. (1990). Vernacular architecture. Current Challenges in the Environmental Social Sciences 24, 30-45. Thorndike, R. L. (1953). Who belongs in the family? Psychometrika 18, 267-276. UN-Habitat (2015). SLUM ALMANAC 2015-2016. Tracking Improvement in the Lives of Slum Dwellers. Technical Report. UN-Habitat (2003). The challenge of slums: global report on human settlements, 2003. Technical Report. Visagie, J., & Turok, I. (2020). Getting urban density to work in informal settlements in Africa. Environment and Urbanization. CORRESPONDING AUTHOR Alessandro Venerandi, Postdoc, ESPACE, University of Cote d’Azur, 98 Bd Herriot, 06200, Nice, France. alessandro.venerandi@univ-cotedazur.fr @dooluoz (twitter)

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Between the walls The two parallel blank walls standing 16 meters tall on each side of the railway passing through Kibera are the physical embodiment of efforts to decrease interference with the train traffic. Authorities demolished previous informal construction along the railway and resettled the residents in newly constructed housing units forming a barrier to restrict movement across the tracks. New informal construction along the train line has emerged and the residents have a pending eviction order. A young woman explains how she obtained her apartment in the blank wall barrier through bribery – ‘you know how it works’.

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155 Informal construction pending demolition along the train tracks

10. Understanding density in unplanned and unregulated settlements of peri-urban Africa: a case study of Maputo, Mozambique Paul Jenkins and Johan Mottelson INTRODUCTION The intricate relationship between sustainability and urban density is a subject of discussion among urban planners and academics worldwide. There are two very different approaches to densification: one argues that density promotes more sustainable urban areas (especially in relation to infrastructure, such as transport), and the other characterises it as creating problems of public hygiene and social pathologies (as well as often being seen as culturally inappropriate). The debate is thus divided, but urban planning policy in the past decades has generally been supporting curtailment of urban ‘sprawl’ and enhancement of ‘compact city’ development through urban planning mechanisms. Since gaining independence, most sub-Saharan African cities have expanded their urban areas enormously – if the ‘urban’ area is defined by the nature of land use, non-traditional social structures and cash-based economics, i.e. what is functionally urban and not defined only in political-administrative terms (Jenkins 2017). This has produced what are commonly termed ‘peri-urban’ areas, as these initially were peripheral – however, now they dominate the urban form, constituting maybe as much as 80–90% of what is functionally ‘urban’ space (see below). Here, the majority of land is often unplanned and unregulated by government, i.e. the so-called ‘informal’.1 Given projections of enormous urban population growth in sub-Saharan Africa in the coming decades (United Nations 2015), the strong likelihood of continued weak state regulatory and investment capacity, as well as the dominance of low-income urban majorities, this chapter argues that the phenomenon of this ‘emerging urbanism’ in peri-urban areas of Africa will continue to dominate (Jenkins 2013). Importantly, this involves densification in parallel with peripheral expansion. Referring to both sides of the debate on densification mentioned above, peri-urban Africa actually displays both trends. In general – with relatively cheap land and limited building investment capacity (in fact most urban areas are produced by self-managed construction over the long term) – the initial tendency has been for (unplanned) expansion. As a result, to date, most studies on African metropoles focus on the rapid urban expansion and few studies focus on concurrent urban densification processes taking place.

156

117

District 2

1 920 261

Marracuene

Greater Maputo

Matola, Boane,

Source: Prepared by the authors from census data

Marracuene

627

290 696

222

107

Boane

1 094 305

Pop. 2007

672 508

5.8

p/h

3.2

1997

Ann. avg. %

Matola City

171

277

197

171

Total %

210 261

227

209 909

161

129 067

958 585

Pop. 1997

KaNyaka

Katembe

122

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KaMubukwana

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KaMaxakeni

'LVWULFW

106

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Nlhamankulu

560 160

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1980–97 change

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Maputo City

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129

106

114

Total %

1.3

Ann. avg.

1997–2007 change

4.8

5.0

p/h

2007

3 070 259

210

1 616 267

199

129

1 101 170

Pop. 2017

160

201

240

117

167

111

101

Total %

0.06

Ann. avg.

2007–17 change

4.4

4.9

p/h

2017

A case study of Maputo 115

157

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Densifying the city?

With limited infrastructure investment, but growing urban populations (the majority being poor), public health can be more of a risk in dense urban areas; however, wider socio-cultural understanding on hygiene mitigates this to some extent, as does improved medical services (and above all else adequate supply of clean water). In this way, as well as others, social and cultural values are changing and adapting to denser urban living, such as changing attitudes to privacy, foodways and ‘cleanliness’, due to more limited living space.2 Will this densification process actually lead to more compact cities? Will these emerging urban areas be more sustainable when more densely occupied? This chapter argues that the answer will also depend on changing social and cultural values, as much as on the capacity to invest in infrastructure (whether state or private) – and much more than on state regulatory capacity. To this end, the chapter examines the densification of peri-urban areas through case studies in Maputo, the capital of Mozambique. However, the main focus of the chapter is – in the context of scarce detailed and geographically registered demographic data – how we can measure density prior to its evaluation.

DEFINITIONAL ISSUES Density is inherently a relative term – mathematically, as the relation of one measure to another, but also concerning how these measures are created. In addition, it is a socially and culturally relative term, as what is perceived as ‘dense’ depends on many structural factors (political, economic, geographical), but also on social and cultural values. As such, what someone in Europe or Asia perceives as dense in an urban area is very different – and different again from what someone in Lagos might perceive, compared to someone in Nairobi. Ordinarily, urban density is a demographic measure divided by a spatial measure (e.g. inhabitants per square kilometre or households per hectare), but it can also be expressed in more technical terms (houses or plots per hectare, Floor Area Ratio (FAR)) – these latter terms always subsuming a relationship with a demographic measure. Not only is the demographic measure variable across the world, and across different urban typologies, societies and cultures (e.g. number of inhabitants per household), but the way the geographic measure is defined can also make a difference. Hence there are ‘gross densities’ and ‘net densities’ – and different urban professionals and governments have different definitions of what is considered dense in relation to such measures. As such, there is no absolute definition of what a dense urban area is, and indeed the relative nature of density also changes over time – something particularly relevant to sub-Saharan Africa urban areas experiencing rapid population growth. What would have been considered either a socially acceptable or a professional/government norm for a dense urban area in sub-Saharan Africa even 20 years ago, and what would be considered dense now, has changed – and will continue to do so. All this means that, apart from different measures, it is very difficult to define what is ‘good’ or ‘bad’ about density, densification or urban expansion. Setting aside the definitional problems outlined above, we can measure trends in densification provided we retain similar and locally relevant measures over reasonable periods, vis-à-vis wider contextual change. How we evaluate these changes in density, however (as previously noted) requires a different process beyond measurement. This chapter now looks at two examples of different densification measurement in the peri-urban areas of Maputo. The first looks at a macro-level, using the recent ten-year national

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census information currently available. The second looks at a micro-level over a selection of unplanned areas, comparing two areas that were largely occupied more than four decades ago in the pre-colonial period (but at different distances from the urban centre) and a new area of urban expansion (outside the administrative city limit). The chapter thus examines the most recent processes of densification in the city’s peri-urban areas through empirical measures, using satellite imagery to examine wider census data in more detail. It then raises queries concerning an initial assessment of the impact of these densification processes.3

MAPUTO CITY – DENSIFICATION DYNAMICS AT MACRO-LEVEL4 While a number of recent academic papers have been produced examining Maputo, only a few deal with urban spatial issues.5 However, none investigate urban density in any detail. This section of the chapter compares the change in census data on the population for the city, across the 1980, 1997, 2007 and 2017 national censuses (see Table 10.1 for detail). Separating out the Maputo City population from the greater Maputo population,6 between 1980 and 1997 the city grew on average by 3.2% annually – close to, but above, the average natural increase (2.7%/ year). This rate of growth dropped in the next inter-census period up to 2007 (to a 1.34% annual average) and then dropped further after 2017, to a 0.06% annual average. However, as seen in Table 10.2, there is significant difference in change between urban districts. As described below, the slow-down in recorded city population growth is in fact mainly due to expansion into the metropolitan area, but also due to some reduction in average household size. In the period 1980–97, all urban district populations rose to some extent, except District 1 (the colonial urban centre), although population growth above the natural increase was only registered in Districts 3, 4 and 5. District 3 includes the UN-funded Maxaquene upgrading project (in the late 1970s), with its expansion into fairly unoccupied land. This is now Polana Canico A – which had been prepared for new urban development prior to Mozambique’s independence, but was abandoned in 1973–74 and largely unoccupied at the time of the project. The other two districts, especially District 4, represent the expanding peri-urban area, with considerable state involvement in land sub-division in the 1980–87 period (the Basic Urbanisation Programme).7 In the 1997–2007 period, there was then a significant overall reduction in urban population in District 1, and minor overall reductions in District 2 and District 3 but continued strong growth in District 4 and significant growth in District 5. Growth rates in District 4 and District 5 were thus equal to or higher than the average natural growth rate. In the 2007–17 period, the above trends continued with an overall drop in population in Districts 1, 2 and 3; Districts 4 and 5 continued to grow demographically, but lower than natural growth levels. In this period, however, the previously ‘rural’ areas of the city (across the bay in Katembe and the island of Inhaca) collectively rose significantly – this being primarily in Katembe, reflecting plans for new access with the construction of a bridge (opened in late 2018) – the previous ferry boat access having restricted urban development. The above demographic change reflects a shifting balance of city population: with the peri-urban area of the city (i.e. all districts except District 1), changing from 80% of the population in 1980, increasing to 93% in 2017.

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Overall, from 1980 to 2017, within the overall urban area, the dominant population location dropped from 60% to 37% in the central urban Districts (1, 2 and 3), with outer urban Districts 4 and 5 rising from 37% to 59% of the total. Hence, the balance of total city population between Districts in this period also changed, from a situation in 1980 where urban district populations had fairly similar populations (except District 4), through 1997 (where Districts 3, 4 and 5 became much larger than Districts 1 and 2), to 2007, when the largest urban Districts (4 and 5) each had three times the populations of the smallest urban District (1) and twice that of District 2. In 2017, Districts 4 and 5 had grown to four times that of District 1, and were also considerably higher than Districts 2 and 3. This enormous growth in the so-called peri-urban area has significant urban administrative implications. In addition, average household sizes have dropped from 5.8 people per household in 1997 to 4.9 in 2017 – this being most marked in District 1, which dropped from 5 people per household in 1997 to 3.4 in 2017. This may reflect the strong preference for middle-class households to reside within the city, with generally lower household sizes. Household sizes in Districts 2/3 also dropped from 6.2/6.3 to 5.4/5.6. This is likely the main source of the population decrease in these older urban districts, because although the number of houses rose from 1997 to 2007, in 2017 it then reduced to be equal to the 1997 total – mainly due to relocations for other forms of urban development. In contrast, the number of houses in Districts 4 and 5 rose from 75 000 in 1997 to 131 000 in 2017, with only a slight drop in the average number of people per household. In terms of density measures, as the urban districts have remained the same in territorial terms throughout the above inter-census periods, relative density changes can be seen as a general reduction in density in both the inner colonial city (District 1) and the two older inner peri-urban areas (District 2 being predominantly unplanned since the 1930s, and District 3 predominantly unplanned from the 1960s and 1970s) – but there was an increase in overall population and density in Districts 4 and 5 – and latterly also taking place in Katembe across the bay. However, to a certain extent, the shrinking household size has also affected these two main expansion areas. As such, the inner peri-urban areas are lowering in gross density, whereas the outer ones are increasing, i.e. reflecting expansion in parallel with densification, which is important to note. In relation to the city and its immediate region, the new 2017 census took place in August of that year and as yet the National Statistical Institute has not made detailed data (i.e. neighbourhood level) publicly available.8 However, there is some data for Matola, as well as the two neighbouring provincial districts, which are seen as comprising the Greater Maputo area – also shown in Table 10.2 Matola’s 2007 population increased by 240% and in the same 10-year period the populations in Boane and Marracuene grew much higher than natural growth rates. Overall, in 2007, the outer parts of the metropolitan area (Matola, Boane and Marracuene) rose from 45% of the approximate 1.9 million Greater Maputo population (Maputo City being the remaining 55%), to 67% of the approximate 3.1 million Greater Maputo population in 2017, i.e. a growth of over two million. However, calculating changing net urban densities in these outer metropolitan areas is difficult; although the territorial area of the Matola municipality and the two provincial districts has not changed, all had (and still have) extensive ‘rural’ and sparsely populated areas – hence calculating urban density change needs neighbourhood census data (not yet available) and also satellite imagery analysis for location of urban growth. However, the most significant impact

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here has been the building of a ring road in the previous urban areas of Matola, opening whole new previously rural areas to urban forms of occupation. This has also affected Marracuene, as the ring road runs along the border between that district and the northern edge of Maputo. It is likely that the trend for continued expansion, with parallel consolidation in outer peri-urban areas (as has happened in Maputo City) will continue across these metropolitan areas. Public transport is also reaching further into the province around the city, both north and south-east – including more train transport – and now also with a new bridge across to Katembe, to the south of Maputo City. Hence, the majority of ‘new’ urban population growth will continue to be accommodated in expansion areas, albeit increasingly outside the administrative boundaries of Maputo, in the north of Matola and along the main transport routes, into the surrounding province (via Marracuene and Boane in particular). As noted, this expansion also entails ongoing densification. In fact, rising land and transport costs (the latter linked to reduction in state fuel subsidies) may lead to the inner peri-urban areas having some resurgence of population as these return to densification (as discussed below), where we explore methods of measuring density in situ in peri-urban areas. In fact, as relatively well-located areas continue to grow demographically and transport costs rise, the current horizontal densification processes may soon become vertical.

MAPUTO PERI-URBAN AREAS – COMPARING DENSIFICATION DYNAMICS AT MICRO-LEVEL This second empirical section presents the results from a study undertaken to explore the development of urban land use and land cover change in unplanned peri-urban settlements. The main purpose was to investigate how land use and land cover had changed in sample settlements, and whether there were differences between the areas related to their distance to the central area of the city. Three indicators were used in the study: urban density, public space, and tree canopy cover, although only the first is referred to here. Longitudinal data for the indicators were measured to examine their development in three different settlements at different distances from the central city. These unplanned settlements were examined because there is virtually no data on urban density development of such settlements in Africa, despite the fact that the majority of the continent’s urban population resides in such areas (as exemplified above in the general data for Greater Maputo).9 This chapter raises the question of whether ongoing (and largely unplanned) urban densification might in fact constitute a more sustainable counterpart to the current parallel rapid urban expansion (as noted in the Introduction). However, to assess this requires functional density measurement in a data-scarce context. As shown above, peri-urban settlements in Maputo account for the vast majority of the population in the city (>90%) and hence understanding what happens within these largely self-produced urban areas is important to understanding overall urban dynamics. Three case study areas in unplanned settlements of Maputo were selected, based on their distance from the central urban area, and the nature of their urban structure. All three areas have an unplanned physical structure, and all three are relatively homogeneous residential areas without any major roads or large/medium industry, businesses or public institutions, thus enabling data extraction relevant for comparison. The sample was based on examination of areas of 9 hectares in the three neighbourhoods of Bairros Maxaquene, Hulene and Guava,

161

162

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Source: Compiled by the authors

7DEOH

120 Densifying the city?

A case study of Maputo

121

approximately one, five, and twenty km, respectively, from District 1 (the central city area). Maxaquene is in District 3 (KaMaxakeni) and hence an inner peri-urban area; Hulene is in District 4 (KaMavota) and hence an outer peri-urban area; and Guava is outside the city limits, and hence a metropolitan expansion area (in the Marracuene district). Satellite images of all three areas were extracted from Google Earth from both 2007 and 2017.10 All six satellite images were scaled in AutoCad; buildings and streets were marked with polylines; for every case these were joined using the Region and Union commands; and the total area for each layer was extracted in the properties bar. An attribute was then developed to quantify the building density of the three case study areas. The data extracted from the six maps thus included numerical data for buildings and blocks, enabling production of proportional data of building coverage. All buildings in the three settlements were single-storey and the building coverage measured in the study is thus equivalent to Floor Area Ratio (FAR). By comparing the 2007 data to the 2017 data, longitudinal comparative analysis is possible, offering insight into the land cover and land use change over time, and therefore densification trends in areas usually not studied quantitatively in any detail vis-à-vis densification. As the Guava case study area was largely undeveloped in 2007, and had suburban levels of built density in 2017, it constitutes a clear case of urban expansion. The data shows increasing building coverage in all three cases from 2007 to 2017. While the numerical increase in building coverage was relatively low, the case study area in Maxaquene – which had the highest FAR in both 2007 and 2017 – experienced the lowest proportional increase of 20.5%. The increase of building coverage for the case study area in Hulene was 31.7% and the increase of building coverage for the case study area in Guava was 687.8%; the area thus underwent an even more significant transformative process. Guava’s transformation can be explained by its peripheral location in 2007, whereas by 2017 Maputo’s urban fabric extended almost continuously to Marracuene 25 km north of the city centre (as explained previously). Guava thus experienced a transformation from semi-rural area to a peri-urban in this period, albeit as a non-formal residential area (part of the neighbourhood in fact was unofficially planned; it was not included in this sample however). As Maxaquene is one of the more centrally located peri-urban areas in Maputo in the inner peri-urban area (District 3), it was expected to have some of the highest building coverage in the city, in fact approximately 35.9% in 2017. The study thus suggests that centrally located peri-urban areas, with a higher density at the start of the trend measurement, experience lower urban densification trends both numerically and proportionally compared to less centrally located peri-urban areas. The data demonstrates that peripheral areas have high proportional increase of building coverage, while the denser areas experience lower proportional increase – to some extent due to the urban expansion process. However, while the three cases are located at different distances to the city centre, the data in fact showed relatively little variation in urban densities. Indeed, while all three cases show increases of urban density from 2007 to 2017, it is estimated that the population of Greater Maputo grew approximately 60% during the same period of time, and the data therefore suggests that the majority of the consequent increase in population has continued to be met by new urban expansion, albeit with ongoing parallel forms of urban densification. In international terms, these neighbourhoods still display relatively low urban density – even centrally located peri-urban areas such as Maxaquene. As asserted above, this may be explained by socio-cultural factors as the current density may be seen as ‘saturated’ in

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Densifying the city?

socio-cultural terms.11 Furthermore, tenure typologies may play a role, as a relatively low proportion of the residents live in rental housing. While cultural factors may have an influence, economic factors are doubtless a factor related to the rising costs of transport (for most peri-urban residents this is public transport of some form or another).12

CONCLUSION The above micro-level case study data supports the macro-level census analysis findings: that urban expansion is still the primary vehicle for housing provision for the rapidly growing urban population of (the now metropolitan scale) Maputo, which could be seen as an indicator of unsustainable urban development and thus considered a policy priority. Importantly however, urban densification is increasingly taking place in the predominantly unplanned settlements in the peri-urban area, which possibly constitutes a more sustainable tendency at macro-level. As the alternative to urban densification would be continuous urban expansion to accommodate the growing population, with consequent increased land and energy consumption at macro-level, mitigation of the negative implications of urban densification at micro-level should arguably be considered of parallel importance as a policy priority. The urban densification of the unplanned settlements occurs today primarily as a result of individual families constructing and expanding houses, with limited state intervention. Public options for constructing high-density rental housing could be considered as an instrument for diversifying tenure options and increasing density in strategically selected areas. However, this was a policy priority in the past under the socialist government, with limited success – and the resources for the necessary housing subsidy were, in fact, never available.13 A key question is whether there would be the political will to use well-located land for this type of re-investment when the current realpolitik is people continuously being resettled from such central land. This is then planned for higher income groups and urban infrastructure – including current plans for upgrading in various inner non-formal areas of the city (Melo & Jenkins 2017a, 2017b). It is in fact these redeveloped central areas that have high-rise built form (due to speculation and de facto land costs) – although not necessarily high densities (due to small household size of upper-income groups that inhabit them). A much more likely form of densification will be a grassroots process of verticalisation, based on the current dominant self-production, ‘non-formal’ process of space and housing in peri-urban areas – such as has happened elsewhere in the global South (e.g. Brazil). This process has already started in Maputo’s peri-urban areas (Melo & Jenkins 2017a, 2017b). There thus exists an opportunity to guide this form of verticalisation, as control of this will not be possible (Jenkins 2017). Such guidance could – for instance – be through some well-located ‘show houses’, as the housing self-managed production process is based on what households and builders see, and can therefore imagine for their own situations (Pinard et al. 2017). The key is to accept that state regulation will likely remain relatively weak and concentrate available resources on guidance, as opposed to control. In this chapter, we demonstrate ways that urban density can be measured in peri-urban areas in data-scarce contexts, helping to unpack the reality of broad data, such as census information. However, we stress that whether the now ongoing densification processes in these peri-urban areas will be ‘good’ or ‘bad’ depends on how they are viewed (by residents and authorities). We believe that they can be guided to provide improved and more sustainable

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urban spaces overall, but this entails different approaches from that of current weak urban planning and regulation.

NOTES 1.

3. 4. 5. 6.

7. 8. 9. 10. 11.

12. 13.

We are deliberately using the term ‘unplanned’ here – rather than ‘informal’ – as some of the so-called ‘informal’ areas are in fact planned in the sense that they have structured land layouts, and indeed there is much that could be seen as ‘informal’ in areas that are in fact ‘planned’ by the relevant urban planning authorities. See Jenkins (2013), Andersen et al. (2015a, 2015b) for discussion. Generally speaking, in rural settlements in sub-Saharan Africa, there are a series of different structures related to separate sleeping, eating, storage, cooking and ablution spaces – as well as for small livestock and growing food. How this is changing in Maputo, with more urban forms of settlement (which are denser), has been documented in some detail by one of the chapter authors in UNDP/ UNCHS 1991, and more recently Jenkins (2013). See also http://www.homespace.dk. For example, Da Costa & Ribeiro (2019); Chiodelli & Mazzolini (2018); Rodrigues (2019); Viegas & Jorge (2019). The first case study was published in Jenkins (2013), here updated. The second draws on empirical work undertaken in 2017 and reported initially at the European Conference for African Studies ECAS 2017 (Mottelson et al. 2017). One of the authors of this chapter has been working and researching in Maputo for 40 years and inevitably this chapter relies on the related extensive publication output. Prior to independence in 1975, there were two cities: Lourenço Marques (created initially in the 18th century) and Matola (created in the 1960s). They were amalgamated post-independence (with new territorial definitions), and renamed Maputo. After new local government legislation in 1987, Matola became a separate municipality from Maputo (i.e. previous Lourenço Marques). Greater Maputo is a de facto metropolitan area that includes both municipalities, but also the two nearest towns on the adjoining province: Marracuene (north of Maputo) and Boane (south-west of Matola), as urban development reaches these through major national roads. While not a de jure metropolitan area (as this does not exist in the legislation), since the 1990s this conurbation has been considered as Greater Maputo. For more information on urban land, including emerging (illegal) land markets, see Jenkins (2001a, 2001b); Melo & Jenkins (2017). The National Statistical Institute also does not undertake any analysis, and to date this analysis of the available data is the first to be undertaken. One of the authors has previously led the process for local planning and academic community. Huchzermeyer (2007); Lupala (2002); Owusu (2013) are a few exceptions. Dates: Maxaquene: 16.09.2007–03.05.2017; Hulene: 16.09.2007–03.05.2017; Guava: 12.01.2007–03.05.2017. An example of this socio-cultural ‘saturation’ is the change from open-air bathrooms to the rear of plots – which are now filling up with residential rooms – and also the emergence of first-floor houses. This has led to more bathrooms being covered, and eventually more being incorporated into building structures. See physical surveys from Maputo in recent research, reported at http://www .homespace.dk. Another example, referred to in this chapter, is the continuing desire for outdoor space with tree cover, despite growing horizontal densification and plot coverage with buildings. Trees are an integral part of the Mozambican peri-urban way of life, providing shade for outdoor living (in the hot humid summer season in particular), also providing fruit, and providing spiritual significance as this is where the ‘pahlar’ libation ritual (for ancestors) takes place. For more information on the urban land market, see Jenkins (2001a, 2013), and most recently Andersen et al. (2015a, 2015b). Even in the much better resourced neighbouring South Africa, this has proved to be impossible economically. The more recent attempts to provide a partial higher rise/higher density form of social housing in the peri-urban areas of Maputo city (the Youth Housing Project and a small-scale development by the National Fund for Housing Development) have both stalled due to lack of funds.

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This form of development, however, continues to be rapidly expanding by the private sector, higher income groups.

REFERENCES Andersen, J.E., Jenkins, P. and Nielsen, M. (2015a). Who plans the African city? A case study of Maputo: part 1 – the structural context. International Development Planning Review (IDPR) 37(3): 329–50. Andersen, J.E., Jenkins, P. and Nielsen, M. (2015b). Who plans the African city? A case study of Maputo: part 2 – agency in action. International Development Planning Review (IDPR) 37(4): 423–43. Da Costa, A.B. and Ribeiro, L. (2019). On the coastline: the genesis of green infrastructure towards a future sustainable landscape for the city of Maputo, Mozambique. Proceedings of the Fábos Conference on Landscape and Greenway Planning. Volume 6: Adapting to Expanding and Contracting Cities: Article 6. Chiodelli, F. and Mazzolini, A. (2018). Inverse planning in the cracks of formal land use regulation: the bottom-up regularisation of informal settlements in Maputo, Mozambique. 3ODQQLQJ 7KHRU\ Practice 20(2): 165–81. Huchzermeyer, M. (2007). Tenement Cities: From 19th Century Berlin to 21st Century Nairobi. Trenton, NJ: Africa World Press. Jenkins, P. (2001a). Emerging land markets for housing in Mozambique: the impact on the poor and alternatives to improve land access and urban development – an action research project in peri-urban Maputo. Edinburgh College of Art/Heriot-Watt University, School of Planning & Housing, Research Paper No. 75. Jenkins, P. (2001b). Strengthening access to land for housing for the poor in Maputo, Mozambique. ,QWHUQDWLRQDO -RXUQDO RI 8UEDQ 5HJLRQDO 5HVHDUFK 25(3): 629–48. Jenkins, P. (2013). Urbanisation, Urbanism and Urbanity in an African City: Home Spaces and House Cultures. New York: Palgrave Macmillan. Jenkins, P. (2017). Working with urban expansion and densification in sub-Saharan Africa: learning from land access and urban development in Maputo. Trialog 120: 28–34. Lupala, J. (2002). Urban types in rapidly urbanising cities: analysis of formal and informal settlements in Dar es Salaam, Tanzania. Kungl Tekniska Högskolan. Royal Institute of Technology, Department of Infrastructure, Division of Urban Studies. Melo, V. and Jenkins, P. (2017a). Urbanisation in Maputo city region urban-rural interface: land demarcation and middle-class advances. Paper presented at II International Conference, ‘African Urban Planning’ (Lisbon, September 2017). Melo, V. and Jenkins, P. (2017b). Between normative product-oriented and alternative process-oriented urban planning praxis: how are these impacting on the development of metropolitan Maputo, Mozambique? Paper presented at II International Conference ‘African Urban Planning’ (Lisbon, September 2017). Mottelson, J., Anderson, J.E. and Jenkins, P. (2017). Urban sustainability in relation to expanding cities in Africa, where non-formal settlement dominates: understanding density through detailed case studies in Maputo, Mozambique. Paper presented at the 7th European Conference on African Studies (ECAS 2017, Basel). Owusu, G. (2013). Coping with urban sprawl: a critical discussion of the urban containment strategy in a developing country city, Accra, Planum. The Journal of Urbanism 26(1): 1–17. Pinard, E., Jenkins, P. and Andersen, J.E. (2017). Investigating the important social security role of house/home in everyday urban African city making: cases from Senegal and Mozambique. Paper presented at the 7th European Conference on African Studies (ECAS 2017, Basel). Rodrigues, C.R. (2019). Climate change and DIY urbanism in Luanda and Maputo: new urban strategies? International Journal of Urban Sustainable Development 11(3): 319–31. UNDP/UNCHS (1991). Housing and living conditions in peri-urban areas of Maputo city. Project MOZ/86.005 (Author, Paul Jenkins). United Nations (2015). World Urbanization Prospects: The 2014 Revision (STESASER.A366). Department of Economic and Social Affairs, Population Division. Viegas, S.L. and Jorge, S.B. (2019). The role of the urban grid in Luanda and Maputo’s current transformation: between the idealised city and the pre-existing self-produced spaces. Architext 7: 114–21.

Intimate street life in Mafalala, Maputo, Mozambique → 166

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169 Kyangwali refugee settlement, Uganda

PART III: PRACTICE-BASED PROJECTS

The following architecture and spatial planning projects were produced in collaboration with numerous individuals and organizations in parallel with the academic work presented in Part II: Research papers. This collection of projects spans across different contexts, scales, and mediums. However, none of these projects confine to the formats of academic research. No research questions are answered, no formal methods are applied, and no previous studies are cited. Nevertheless, these projects address many issues related to the general topics investigated in the research papers presented in Part II through less rigid forms of exploration. More specifically, these practice projects examine issues such as built densification, access to infrastructure, and land use management. Furthermore, the Royal Danish Academy has historically emphasized nonacademic forms of inquiry and epistemological production. Accordingly, the projects represent alternative mediums to formal academic papers for discussing the built environment in the context of informal settlements in East Africa. The wider significance of these practice-based projects is further discussed in Part IV: Conclusion.

SPATIAL PLANNING IN KYANGWALI

CAMP + is a project on sustainable development and resilience in the Kyangwali refugee settlement, in Western Uganda initiated by CARE Uganda and CARE Denmark. The local administration of the settlement lacks the capacities to carry out spatial planning and land use management. Consequently, the land is used inefficiently compromising sustainable development in the settlement. A method for implementing spatial plans and carrying out land use management without specialized professionals was developed and tested as a part of the CAMP + project. The method relies on drones, smart-phones, and photogrammetry software for geospatial surveys and smart-phones for implementation of spatial plans and land use management. Accordingly, the project examines new and less costly methods for carrying out spatial planning and land use management. Such methods may also be relevant in relation to the future administration of the urban development in the region, particularly in relation to informal settlements. The project was developed in collaboration with CARE Uganda, CARE Denmark, Lene Lange Bio Consultancy, and SLA.

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Kyangwali is located in Western Uganda in proximity to Lake Albert and the border of Congo. More than 100,000 refugees live in the settlement, primarily from Eastern Congo along with smaller numbers from South Sudan and Burundi. The conflicts in the neighboring countries are unlikely resolved in the near future and the refugee settlement will likely turn permanent over time. However, inadequate spatial planning and consequent consolidated inefficient landuse threaten sustainable development. Ugandan policies provide registered refugees a piece of land with the intention of creating the conditions for self-sustaining local food production. However, lack of appropriate land cultivation methods degrades soil fertility and will decrease food production over time. Furthermore, the use of firewood for cooking and timber for construction of houses leads to extensive deforestation in the area. Land use management plays a crucial role in relation to these issues. Land is a limited resource and inadequate spatial planning leads to inefficient land use. The inadequate land use management leads to excessive space consumption for accommodating the refugees and thereby increased expansion of the settlement. Some refugees settle on steep hills and in flood prone areas unsuited for living, resulting in compromised livelihood. There are great variations in the amount of land each family receives due to lack of formal procedures for land allocation for new refugees, contributing to inequality and conflicts over land. The lack of roads providing access to the individual plots will complicate future implementation of infrastructure (e.g. water and electricity). It is less costly to address spatial planning issues early in the settlement formation process, as the urban form consolidates over time when more permanent buildings are constructed. Accordingly, the issues relating to the ineffective land use management will likely exacerbate over time. In response to the inadequate land use management in the refugee settlement, alternative methods for carrying out spatial planning and land use management based on the limited local resources were developed as a part of the project. A manual describing the tools and methods was produced for local implementation. A pilot project which tested the proposed project methodology was implemented in 2020.

Planned and unplanned areas compared

Project methodology

Unplanned spatial structure, Kyangwali refugee settlement

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Method The project is based on geospatial surveys carried out with drones and smartphones, development of plans using AutoCAD and GIS, and spatial plan implementation based on smartphones and GPS-navigation applications. Initially, a geospatial survey is carried out based on systematic collection of high-resolution aerial photos of the intervention area and the wider context with a drone. The aerial photos are subsequently processed using photogrammetry software (e.g. Pix4D) to generate high-resolution geo-referenced orthophotos and digital elevation maps. Additional surveys of the limits of the area for the intervention and land use boundaries not visible in the orthophoto are traced using GPS-navigation on a smartphone and a GPS-tracking application (e.g. SW Maps). The geo-referenced orthophoto and tracked boundaries are placed and automatically scaled in QGIS. Land use plans are developed based on these surveys in AutoCAD and QGIS and exported in KML format. The KML file of the plan is opened using a GPS-navigation application (e.g. Google Earth) on a smartphone. Implementation of the plan is carried out by using the GPS-navigation application on the smartphone for identifying the location of the land use boundaries and thereby subdivide the land. Accordingly, basic experience with Google Maps or similar applications for navigation will essentially enable anyone to carry out land use management and implementation of simple land use plans. Consequently, specialized professionals are only needed for the initial survey and the development of the plan. The implementation and subsequent land use management can thus be carried out by the local administration or NGO personnel in the settlement which thereby lowers costs of land use planning and management. GPS-navigation based on smartphones is not as accurate as professional land surveys. Nevertheless, since the deployment of the L5 band in 2018, accuracy is largely within 30 centimeters. The land use plans allocate different zoning areas based on different land use categories such as residential, road, natural resource, or institution. Each zoning area is given an ID, specifying the land-use category and a number for identification. Boundary markers refer to the nodes in the corners of each zoning area which are used for subdivision of land. These are also given a number for identification. Each boundary marker thus has a unique ID based on the plan ID, zoning area ID, and the boundary marker number. A spreadsheet containing the unique IDs of the boundary markers and the GPS coordinates of each boundary marker is automatically generated based on the plan file in QGIS. Individual plots are not registered as these are demarcated with measurement tape based on the general land use boundary markers on site in order to reduce the amount of data in the spread sheet. Residential zoning areas are subdivided into plots of 50 x 100 feet based on guidelines

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provided by the government. The spreadsheets and the plans are stored online. These may provide the basis for local land use management and resolving land disputes. Furthermore, these files may provide the basis for future formalization and regularization of the land as the settlement does not need to be surveyed, planned, or restructured. Accordingly, such formalization procedures will be less costly and thus more feasible. More importantly, such planning efforts may reduce settlement on unsuited areas, enhance more equal distribution of land, and decrease costs of infrastructure. In addition, the tools may increasingly guide reforestation of the neighboring areas. Accordingly, these simple efforts to carry out spatial planning and land use management may increase the land use efficiency, improve livelihood of the inhabitants, and enhance sustainable development. The development of individual residential plots is overseen by local democratically elected representatives of the ‘Refugee Welfare Council’ (e.g., the local administration). The residential plots are subdivided in three areas: 1) Front yard; 2) Buildings; 3) Back yard. Construction is prohibited in the front yard in order to avoid street encroachment. Construction is also prohibited in the back yard in order to maximize food production. A zone for construction is laid out between the front yard and the back yard. Houses, chicken hatcheries, latrines, and compost systems are only permitted in this area. Latrines and chicken hatcheries may be built in proximity in order to reduce issues with odor. Latrines should be located in the back of the houses to avoid contamination of street space and increase privacy. Separation of the latrines from the food production will also decrease the risk of diseases. Front yards will likely become active social areas where the residents spend time while others pass by on the street. Inter-cropping in the back yard is advised to increase yields and diversify nutrition. Fruit trees and nitrogen-fixing trees are recommended in each back yard to provide needed shade for lower crops. Nitrogen-fixing coppice is recommended for hedges in order to provide privacy, soil nutrients, and a source for construction materials. The nitrogen-fixing plants, the compost system, and manure from chicken hatcheries are essential for improving soil quality and thereby increase food production. A fruit tree or nitrogenfixing tree may be planted in the front yard to provide shade for the most active social space along the street. Kitchen gardens and seed production should be located in the back yard. These guidelines were developed in order to increase food production, in part by increasing the productive area of the plot and in part by improving the soil fertility. On this basis, the guidelines seek to reduce malnutrition as well as provide locally sourced construction materials and thereby reduce deforestation in the context.

50 feet 100 feet

Neighbour

Zone 3 - Crops - 60 feet Road Zone 2 - Buildings - 35 feet

Neighbour

Zone 1 - Front yard - 5 feet

Guidelines for construction

Fruit trees / Nitrogen ﬁxing trees

Nitrogen ﬁxing coppice hedge Inter cropping Kitchen garden + seed produc�on Latrine, compost and chicken farm House

Guidelines for crop cultivation

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Context, 1:10000, high resolution orthophoto of Kavule produced with a drone and Pix4D photogrammetry software

A pilot project was implemented in 2020 in order to test and evaluate the developed methods. A sub-area of the settlement known as Kavule was surveyed and a plan was developed. The settlement administration allocated an initial site for the pilot project but the site was subsequently given to another organization as implementation was stalled due to the COVID-19 pandemic. However, the settlement administration subsequently allocated an alternative site for the pilot project within the surveyed area and the local partners were able to record a GPS track of the boundaries of the new site using a smartphone and the SW Map application. A new plan was developed, based on these

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boundaries and the detailed orthophoto. The plan lays out a road for accessing new residential pilot plots and a small community garden. Although the scale of the pilot project is limited, application of these new methods revealed the possibilities in testing alternative low-cost techniques for land use management based on new technologies in order to optimize the use of resources and enhance sustainable development. Such alternative methods for urban planning and land use management may also provide more viable options for future regularization of informal settlements and planned urban expansion in major cities in East Africa.

↑ Pilot project plan, 1:2000

↑ Project implementation via remote support, photos by Mary Awori

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177 Unsanitary conditions in Antohomadinika, Antananarivo, Madagascar

Tana toilet blocks, phase 2, photo by Mitantsoa Rakotoanosy

TANA TOILET BLOCKS

Tana Toilet Blocks is a project on sanitation design for public schools in Antananarivo, Madagascar. School toilets provide the only option for accessing adequate sanitation for many children from impoverished neighborhoods in Antananarivo. Consequently, school toilets play a crucial role for the hygiene conditions among children in such urban areas. However, lack of appropriate design solutions for the school toilets decrease the usability and ultimately compromise hygienic conditions for children in these communities. This project sought to improve the design of school toilets in order to address issues with public hygiene for impoverished children in Antananarivo. The project was developed in collaboration with Water and Sanitation for the Urban Poor (WSUP). Nearly half the population of Madagascar lives in severe poverty and inadequate access to water and sanitation has a debilitating impact on health, well-being, and productivity. Nationally, water-related diseases cause at least a quarter of all deaths of children under five in urban areas. Two-thirds of the population in Antananarivo lives in informal settlements characterized by inadequate access to water and sanitation. This has a significant impact on the health, safety, and dignity of the residents of such low-income communities. WSUP has worked with the municipality in Antananarivo on designing and implementing school toilet projects in order to improve the hygiene conditions for children in impoverished communities.

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The Tana Toilet Block project sought to lower costs and improve the quality of school toilets. The project included an analysis of the workflow and the design of previous school toilet projects. Secondly, interviews with users and workshops with stakeholders highlighted a number of problems with previous projects. A design concept was developed in response to these findings consisting of a ‘toolbox’ including detailed toilet drawings split up in modules. This enabled faster planning of new toilet projects, utilization of best-practice solutions, and application of lowcost construction methods. On this basis, the project was successful in improving the user experience, reducing costs of construction, and reducing time spent on planning the toilet projects by the WSUP staff.

Tana toilet blocks, phase 2, photo by Mitantsoa Rakotoanosy →

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WASH WASH is an acronym for “water, sanitation, and hygiene”. According to the United Nations Sustainable Development Goal 6, everyone should have access to clean water and adequate sanitation by 2030. Consequently, WASH constitutes a key public health issue within international development. WASH can improve health, life expectancy, student learning, and gender equality. Accordingly, WASH is important in reducing illness, death, and poverty as well as enhance socio-economic development in developing countries. In 2017, 2.3 billion people lived without adequate sanitation facilities and 844 million people lived without access to safe and clean drinking water, according to The World Health Organization (WHO). Although access to clean water and sanitation is improving at a global scale compared to previous years, the progress is slow and if the current development continues, SDG 6 will not be achieved by 2030. Worldwide, approximately 700,000 children die every year due to diarrhea, partly caused by inadequate access to WASH. Studies have shown that improved sanitation provision in schools is linked with higher female-to-male enrolment ratios, and have reduced drop-out ratios for girls. Accordingly, adequate access to WASH not only has direct health benefits for children, but also impacts cognitive and intellectual development during their formative years in the school system. Interviews and workshops In the wake of developing and implementing toilet projects for 25 different schools, previous toilet projects were evaluated in order to optimize the design process and improve the quality of the future toilet projects. The project team inspected 15 school toilet blocks in Antananarivo over two weeks. Some were previous WSUP projects and some were part of the survey for future toilet projects. The project team spoke to students, guardians, and teachers to uncover their needs related to WASH. The evaluation of previous toilet projects highlighted a number of issues that the Tana Toilet Blocks project sought to address. The user interviews identified the following issues: • Toilet cubicles have smell and heat problems • Locks and cistern flushes are often broken • Toilets for disabled persons are typically locked and not used as they are considered exclusively for disabled persons • Shower components are of bad quality and often broken • Some schools do not see the necessity for a shower so the showers are locked and not used • Menstruating girls are not using the showers as intended because they are embarrassed • Kids do not wash their hands with soap • Hand wash station faucets and taps are often broken

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↑ School visit

Workshop with stakeholders →

The evaluation highlighted that toilet blocks and handwashing facilities are often not optimally designed and do not adequately consider the needs of the users (e.g. female students). Non-functioning and badly designed school toilets limit the options for good WASH habits. This leads to bad hygiene practices by the students and limits the positive ripple effects to the wider community. The project team presented the findings to the Ministry of Education, Water Aid and other sector actors in a workshop to come up with possible solutions to these uncovered issues. The following solutions were suggested by participants of the workshops: • Toilets for disabled persons and toilets for teachers should be merged as one toilet unit • Shower units should only be built if the school specifically asks for it • Toilets should have better airflow through roofs • Toilets should have a simple lock system • Toilet blocks should have a simple wet room with a tap for cleaning utilities • Mirrors above hand wash stations will increase the likelihood of users washing their hands • WSUP should buy high-quality components in bulk and provide them to the contractors • Students should pass by the hand wash station on the way out of the toilet blocks

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Conventional toilet design, section

Technical assessment of previous projects The project team conducted a technical analysis of previous toilet projects based on observations of built projects and project drawings in order to reduce costs and improve the quality of construction. This included an assessment of construction and detailing of toilets, an analysis of typological models, and an analysis of the toilet project design workflow. The technical assessment identified a number of issues and questionable solutions in previous WSUP projects. Most, if not all projects were characterized by excessive use of steel and concrete, resulting in higher costs without increasing the quality of the toilet projects. In most cases, 20x20cm reinforced concrete columns were placed with around 150 cm spacing. Some projects had timber embedded in the wall structure, causing the timber to decay and the wall to crack as timber expands when exposed to humidity. Some projects lacked roof overhang, causing the walls to deteriorate. Some projects featured in-situ cast concrete gutters characterized by inferior technical performance and higher costs compared to regular gutters. Some projects included rainwaterharvesting concepts. However, all of these systems were malfunctioning. In one case, the PVC-pipes had cracked and thus failed to fill up the large plastic container for rainwater harvesting. In another case, the rainwater was led from the roof into the urinal as a flush mechanism. However, as a consequence, the septic tank filled up quickly. The school did not have the resources to empty the septic tank and ended up reworking the pipes, leading all waste from the entire toilet block directly into a neighboring canal. Many of the previous projects had suspended wooden ceilings. Although this detail does provide increased privacy in the cubicles, it increases costs and amplifies problems with odor and heat due to decreased air circulation. The typological analysis of previous WSUP school toilet projects identified four different toilet models, deployed with minor variations in all the schools. The variations included the number of cubicles, unisex units/separation of gender, wheelchair access, indoor/outdoor urinals, and location of handwash stations. However, each of the four identified

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Conventional toilet design, plan

typologies had almost identical plan solutions. All toilets were single-story, with the following four plan layouts: A) Single row of cubicles with direct access; B) Single row of cubicles with an enclosed access space; C) L-shaped plan with direct access to cubicles; D) Double row of cubicles with central corridor providing access to each side. Typology A was by far the most common. The workflow assessment concluded that the WSUP team used much of their resources developing in-situ solutions independently, which ended up with very similar results. At the start of the design process for new toilet projects, the WSUP staff would carry out a survey assessing the needs of the school and the space available for the project. Subsequently, a member of the WSUP staff would design a toilet from scratch. Each WSUP project engineer used different solutions and applied different design standards. The team delivered basic sketch projects with limited detailing to contractors through a tender process. The contractors would subsequently carry out the detailing of the projects according to their own standards. Different contractors carried out the projects, depending on the location of the projects. Accordingly, many resources were allocated to developing new designs for each new project but with similar end results, little detailing, and solutions determined by the individual engineer and contractor. Even though each school has individual needs, the components of school toilet blocks are the same (e.g. urinals, toilet cubicles, handwash stations, etc.). Despite school toilet blocks generally consist of the same components and have limited plan solution variations, the toilet projects were designed from scratch during each project resulting in much time spent on producing basic drawings and detailing determined by the contractors. The analysis suggested that a higher degree of standardized solutions could both reduce time on designing and developing projects, avoid technically flawed solutions, and achieve a higher level of detailing before delivering the projects to the contractors.

Conventional toilet design

Technically flawed details

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Tana toilet blocks, phase 1, photo by Mitantsoa Rakotoanosy

Project The evaluation of previous toilet block projects highlighted issues with usability, technical performance of the buildings, and inefficient workflow regarding the development of new toilet projects. The new design sought to address these issues and thereby improve usability, reduce costs, and increase the quality of construction of new toilet blocks. The project included two phases, encompassing the construction of 10-15 school toilet projects each. The first phase of the project was developed based on the interviews, workshops, and technical assessment of previous projects. In the subsequent second phase, the design was iterated based on evaluation of the first phase of the project including both technical assessments as well as feedback from users and contractors. The design features wall structures made entirely of bricks in order to address the excessive use of reinforced concrete seen in previous toilet projects. Thereby, the design excludes some of the costliest parts of the structure. The design was inspired by the common contemporary low-cost construction practice in informal settlements as well as examples of cultural heritage buildings in Antananarivo made of bricks and timber. The design features an open roof structure without suspended ceilings. This solution both lowers costs and decreases smell and heat issues through increased natural ventilation. The large roof overhang protects the facades from the rain and thus increases the building lifespan. Furthermore, the roof features steel joints between the timber structure and the brick walls, eliminating issues with cracking walls and rotting timber seen in previous toilet

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projects. The project included a number of design concepts for enhancing WASH oriented behavior, such as placing handwash stations by the entrance/exit of the toilets as well as installation of mirrors on the handwash stations in order to encourage more frequent hand washing. The project sought to streamline the workflow of the design process and emphasize documented well-functioning design solutions, rather than each designer and contractor using their own preferred solutions. On this basis, the project team developed a school toilet design toolbox including a catalog of detailed AutoCad and Sketchup drawings of the elements needed to plan a school toilet project subdivided into modules. This included modular designs of standard toilet cubicles, hand wash stations, toilet units for teachers and disabled students, shower units, and urinals. Each module features detailed plan, section, elevation, and 3D drawings, that can easily be copied and put together to a complete toilet design in a few minutes. By using the toolbox rather than drawing up new toilet projects from scratch, the time needed for planning and designing a new toilet project is reduced significantly. Furthermore, a much higher level of detail is achieved before delivering the projects to the contractors compared to the previous workflow. More importantly, the toolbox establishes standardized best-practice solutions based on the evaluation of previous projects. The modular system allows adaptability to the needs and physical context of the individual school through Tana toilet blocks, phase 2, photo by Mitantsoa Rakotoanosy →

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Inspirational local architecture

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Construction site, phase 1

Overuse of concrete and imitaded brick plastered walls in phase 1

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Tana toilet blocks, phase 2, photo by Mitantsoa Rakotoanosy

sub-division of the components needed to plan the same typological variety of toilets seen in previous projects while having a set of standardized detailed solutions. The toolbox includes an excel sheet with material quantities and costs for each unit, thereby facilitating rapid quantity surveys and cost estimates. On this basis, the project was able to reduce costs of planning and construction while improving the quality of the toilet blocks for public schools. The first phase of the project included toilet blocks for 12 schools in different parts of Antananarivo and was initiated in 2018. Two of these were refurbishments of old toilets and 10 new toilets were designed using the toolbox. The projects varied in scale and typology depending on the needs of the school and the constraints posed by the physical contexts. Four different contractors implemented the designs. As these contractors carried the legal responsibility of the construction projects, each contractor made amendments to the design based on their individual convictions of sound construction practice. Some contractors implemented designs loyal to the intentions of the new design toolbox. Others, made significant changes in the design, including decreased roof overhang and use of concrete in the structure with possible implications for durability and costs.

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The second phase of the project was implemented in 2019 based on a technical assessment of the toilet blocks constructed during the first phase as well as interviews with users and feedback from contractors. The first phase succeeded in improving usability, reducing construction costs, and streamlining the workflow of the WSUP staff. However, the link between the WSUP staff and the implementing contractors showed some room for improvements. Some contractors expressed concerns about the stability of the walls without a reinforced concrete peripheral tie between the top of the wall and the roof structure. Some contractors expressed concerns regarding the height of the pitched roof and its exposure to the risk of tropical storms. Accordingly, the toilet toolbox was iterated based on an evaluation of the first phase. This included addition of a peripheral tie made of reinforced concrete, increasing the stability of the wall structure while strengthening the joinery between the wall and roof structure. Furthermore, the height of the roof was reduced in order to decrease the risk posed by storms. The project highlights that a holistic design approach based on analysis of the wide variety of complex issues surrounding architecture projects can yield results in optimizing the use of resources and enhancing sustainable development.

Dallage

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Urinoir pour fille interieur

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Dallage

2050

Toilette

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Douche

1600

Urinoir pour garçon exterieur

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DLM

Responsable du nettoyage (tableau noir)

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Responsable du nettoyage (tableau noir)

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Toilet toolbox, phase 2

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193 Tana toilet blocks, phase 2, photo by Mitantsoa Rakotoanosy

Mount Hulene A grotesque man-made mountain of garbage emerges from the ground in the suburban informal settlement of Hulene, located approximately 10 km from the center of Maputo. Constant clouds of smoke of burning trash rise from the landfill and filters the glimpses of the city skyline through a misty haze from the steep rubble-slopes of Mount Hulene. Local groups of scavengers carefully examine these piles of garbage in search of recyclable plastic bottles which provide a basic source of income. In 2018, parts of the rubbish mountain slid and destroyed several adjacent houses killing 17 people after a period of heavy rain.

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MAXAQUENE TXOMBENE

Maxaquene Txombene is a public space project in Maputo, Mozambique utilizing recycled plastic as the primary construction material. The project transformed an old defunct drinking water fountain into a shaded recreational space in the centrally located informal settlement of Maxaquene A. The structure was built of beams produced of recycled plastic waste and the concrete blocks used in the landscape design were cast in reclaimed five-liter water bottles. Thereby, the project sought to advance the principles of circular economy in construction while discussing the cultural heritage in the informal settlements in Maputo. The project was carried out in collaboration with Remígio Chilaule and students from the Faculty of Architecture and Physical Planning, Universidade Eduardo Mondlane and Institute of Architecture, Urbanism and Landscape, The Royal Danish Academy. In Maputo, more than 75% of the population lives in informal settlements. The public space in these areas is typically in poor conditions due to the extra-legal status of the neighborhoods and consequent lack of public investments in infrastructure. Nevertheless, the public space plays a crucial role for social life in these settlements, as the residents and particularly children spend much of their free time outside their homes. This project sought to improve the quality of a small public space in this context. The government built a number of public water fountains, supplying the informal settlements of Maputo with drinking water in the 1980s. Today, most households have direct

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access to drinking water and the water fountains are defunct. However, these fountains remain a part of the cultural heritage and are typically located in small public spaces, where people used to stand in line to fetch water. The project sought to discuss the cultural heritage by adding a new use to one of these old structures. The old water basins were filled with concrete and plastered, providing a smooth surface for sitting. A light roof structure and a backrest were added to the old fountain, providing shade in the hot climate. Finally, a crumbling open drainage passing through the public space was renovated in order to improve the sanitary conditions. Billions of plastic bottles are produced each year and only a small fraction is recycled, compromising sustainable development. Plastic is a pollutant, as it is not easily degraded by the environment. However, as it does not rot or rust, it is also a desirable construction material. The project utilized plastic beams made of recycled plastic waste, thus pioneering the use of plastic as a structural component in construction in Mozambique. The concrete blocks used in the landscape design were cast in reclaimed five-liter plastic bottles. The smooth-surfaced concrete blocks thus appear as petrified water bottles, both referring to the water-themed old fountain and the drainage as well as underscoring the point about recycling plastic. On this basis, the project discusses issues related to the cultural heritage in the informal settlements as well as the circular economy in the construction sector in Mozambique.

Defunct water fountain transformed into recreational public space

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Structure made of recycled plastic

Plastic waste experiments The plastic beams utilized in Maxaquene Txombene were produced in a plastic recycling workshop established in Maxaquene in collaboration with Jakob Kisker and Celso Machaieie. The initiative seeks to utilize recycled plastic waste as a construction material and thereby advance the principles of circular economy in the construction sector in Maputo. In the informal settlements of Maputo, the quality of construction is often low and the lifespan of buildings is generally short. Much of the wood used in construction has particularly short lifespans due to humid climate, decay, fungi, and infestation by insects. In parallel with the challenges in the built environment, plastic waste is widespread in low-income areas in Maputo. There are limited initiatives to handle or recycle plastic waste, leading to pollution of the environment. On this basis, the initiative is currently seeking to develop construction methods utilizing plastic waste as a building material. The initiative has established a small production unit in Maputo testing components for construction made out of recycled plastic. Plastic recycling is a relatively simple process including few steps. Different types of plastics have different properties as well as different melting and boiling points. It is advisable to sort the plastic before it is recycled as toxic fumes can develop when some types of plastic are heated above the boiling point. The sorted plastic is cleaned in order to ensure the quality of the product and not damage the machines. Production of plastic beams requires a plastic shredder and

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a plastic extruder. The plastic shredder cuts larger pieces of plastic into smaller pieces, which is necessary for the later production process. The extruder compresses the smaller plastic pieces through a screw in a heated pipe that melts and compresses the plastic into a mold with the dimensions of the plastic beam. As plastic has a fairly low melting point compared to other construction materials, structures made of plastic will easily collapse in the case of a fire. Accordingly, the fire hazard issues exclude using plastic for indoor structural purposes. However, the resistance to the environment makes it ideal for public space furniture, façade cladding, or sanitation design. New prototypes for such usage are under development. The prototyping process highlighted that bottle caps (high-density polyethylene, HDPE) are suited for producing beams while plastic wrap and plastic bags (low-density polyethylene, LDPE) is suited for producing plastic sheets or tiles for roofing or façade cladding. The project underscores the necessity to transform our contemporary linear production model into a circular economy, whereby waste is recycled instead of accumulating in the landfills.

Decaying roof structure

Landfill in Maputo

Sorted plastic waste

Shredded plastic waste

Plastic extrusion machine

Plastic beams, photo by Anna Wahlén

Prototyping, photo by Celso Machaieie

Workshop visit with architecture students, photo by Celso Machaieie

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205 Private outdoor space in Maxaquene, Maputo, Mozambique

Matola Municipality

Airport

City center

District boundary Main road Railroad Project area 5 km

Maputo overview

LAND RIGHTS IN MAPUTO

Land Rights in Maputo is a project focusing on insecure tenure and gentrification in the informal settlements of Maputo, Mozambique. Residents of informal settlements lack legal protection of their private properties due to lack of formal land titles and construction without permits. Accordingly, the public authorities may evict the residents of such areas without compensation due to the extra-legal conditions of the buildings and occupation of the land. The Land Rights in Maputo project seeks to support communities of informal settlements in Maputo, Mozambique in formalizing their land ownership. A pilot project is currently in the process of implementation in the centrally located informal settlement, Maxaquene D. Approved urban plans are required to formalize land ownership. Accordingly, an urban plan for a part of the neighborhood was developed for the pilot project area. The plan has been approved by the municipality and the project is now seeking to assist the local community of the pilot project area through the legal process of obtaining formal land titles. The project is carried out in collaboration with Jørgen Eskemose, Architects without Borders - Denmark, Estamos, and Bulande Arquitectos. The project is funded by CISU (Civil Society in Development, Danida). Context: Maputo Maputo is characterized by social inequality and urban development without effective planning, enforcement of regulation, and appropriate infrastructure provision. The formal city center was planned and developed by the Portuguese colonial rule until independence. The city center has wide streets structured in a grid layout, as well as relatively well-functioning infrastructure. The formal urban core is surrounded by a 20-25 km belt of informal settlements, characterized by a lack of planning and inadequate basic infrastructure. Due to political instability and the scarcity of resources after independence, the city developed with limited planning and affordable housing options. The majority of the population were financially excluded from the formal land and housing market and settled on land without formal legal permits. This development continues to this day, resulting in vast unplanned urban areas with limited infrastructure provision.

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The public administration of the city has a hierarchical structure, with public administration officials at each level. The municipality is subdivided into seven districts (distrito). Each district is subdivided into a number of neighborhoods (bairro), 53 in total. The neighborhoods are subdivided into a number of blocks (quarteirão), typically covering 35-100 housing units. Some blocks are subdivided into 10-cells (10 casas), but blocks are typically the base of the governance structure. Blocks are managed by block leaders (chefe de quarteirão) who receive no formal salary and are residents of the block they administer. However, both neighborhoods and districts have formally employed professionals carrying out the administration of the neighborhoods, including the informal settlements. Urban planning in Maputo is usually linked to the administrative systems. The urban plan at the municipal level, covering the whole city, is known as the structural urban plan (PEUMM - Plano de Estrutura Urbana do Município de Maputo). The structural urban plan includes land use categories and main infrastructure, as well as a formal/informal ownership classification. Urban plans (PPU – Plano Parcial de Urbanização) are usually carried out at the neighborhood level, which includes local street layout and dimensions as well as infrastructure, urban densities, and building regulation. Finally, detail plans (PP - Plano de Pormenor) are developed at the block level, specifying plot boundaries, street dimensions, densities, zoning, building typologies, and open spaces. Construction permits can only be issued on formally owned land in areas with approved urban plans by the municipal department of planning. Nevertheless, construction permits are often issued by the local administration, without legal basis and with no top-level municipal involvement. Land rights in Mozambique All Mozambican land was nationalized following independence in 1975. The Mozambican land law does not allow people to own or sell land. Instead, an individual can be granted the right to use and benefit from the land, known as DUAT (Direito do Uso e Aproveitamento da Terra). These rights can be transferred to another person when the house on a given plot of land is sold. The land law of 1997 recognizes the rights of long-term residents of informal settlements and DUATs can be granted through ‘the rights to use and benefit from the land through ten years of good faith occupation’. However, it is only possible to obtain a DUAT, if the following conditions are met: • • • • •

A master plan (PPU – Plano Parcial de Urbanização) for the area has been approved A detail plan (PP - Plano Pormenor) for the area has been approved The plot has access for cars Documentation of the residents and a survey of the house are provided The house and plot comply with the regulatory requirements of the approved urban plans

Rail road

University faculty

Hospital

Industry

Public institution

Unplanned area Planned area

School Ministry of agriculture

Maxaquene D Stadium

Pilot project area

School School

Maxaquene D context 0 100 200 400m

Overview of context

Workshop with local community, photo by Pedro Bulande

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Model of current urban conditions in pilot project area

These formal requirements are occasionally disregarded, as there can be legitimate opposing considerations to the regulation. The municipality, UN-Habitat, and locally commissioned professionals planned some areas after independence. These areas have well-organized urban structures, mostly accessible by cars. However, despite the planned urban structures many of these areas are informal settlements as the plans for the areas are not formally approved, construction is largely built without permits, and most of the residents lack formal land titles. In these cases, the municipality accepts land ownership formalization processes without an urban plan (PPU) and only a detail plan (PP) for the area is required. Furthermore, in the informal settlement Chamanculo C, the municipality accepted initiating a land ownership formalization process without access to the plots for cars, as it would require demolishing a significant number of houses in the area. Formal land rights are unattainable for the majority of the urban population due to several issues. The vast majority of informal settlements do not fulfill the formal requirements as they lack approved urban plans and many areas lack access for cars. These areas thus require surveying, planning, and costly readjustment interventions, which the residents are largely unable to organize due to limited economic resources. Furthermore, in the few areas where DUAT is attainable most residents lack the resources to produce the applications. Most residents of informal settlements with a formal land title (DUAT) have likely obtained it through informal procedures, either through bribery or personal relations within the municipal administration irrespective of plot compliance with the formal requirements. There

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is limited precedence for large-scale evictions in Maputo and despite the extra-legal occupancy of much of the land in the city, most residents do not consider insecure tenure an important issue. However, as the city is growing rapidly, land prices of centrally located areas are increasing. This is particularly an issue in the zone around the formal urban core, where investors are seeking land for the development of new residential areas for middle- and upper-class citizens. Without formal rights, the residents of these informal settlements are in a fragile situation as the law does not provide protection of their private properties. The investors have large economic resources, knowledge of the law, and possible ties to the authorities. The low-income residents of these centrally located informal settlements are thus in an asymmetrical bargaining position with the investors. Accordingly, these residents are typically pushed out with minimal compensation. Although the scholarly literature is ambiguous about the general impact of land ownership formalization, most studies acknowledge that land titling programs increase tenure security. Project The Land Rights in Maputo project seeks to formalize the land ownership in Maxaquene D and thereby provide legal protection of the private properties of the residents. The project has developed an urban plan for a pilot area which has been approved by the municipality. The project is now in the process of planning workshops with the community of the pilot project area in order to complete applications for formal land titles (DUAT).

Model of future development of pilot project area

Maxaquene D was selected for the pilot project as it is centrally located and gentrification of the neighborhood is likely in the following decades. Formal land titles will likely improve the bargaining position of the residents in this process and thus protect their properties from investors seeking the land for new urban development. Additionally, most of the neighborhood already has a structured street layout as a result of a land readjustment program by UNHabitat in the 1970s. Accordingly, it is not necessary to develop a master plan (PPU) for the area, as an approved detail plan (PP) is sufficient for obtaining DUAT in areas with planned urban fabrics. This enabled a more realistic small-scale pilot project. Furthermore, little restructuring of the urban layout is necessary for complying with the urban regulation. Accordingly, the cost of implementation will likely be limited. Finally, many informal settlements in the city have planned urban layouts, due to the planning categories discussed in the introduction (page 30-31). Accordingly, development of a methodology for formalizing land ownership of such areas in a low-cost procedure could pave the way for larger-scale land ownership formalization processes in the city. The pilot project seeks to formalize land ownership in a block in Maxaquene D. The block has approximately 500 residents and is located adjacent to a paved street connecting two major roads in the city. The area has a structured layout with rectangular plots of approximately 10x15m and 2-4m wide streets characterized by some encroachment. While most of the plots have access through this street network, some plots only have access through narrow alleys or the neighboring plots.

A detail plan (PP) for the block was developed, as this is a prerequisite for the residents to obtain formal land titles (DUAT). The plan was developed in dialogue with the municipality, in order to comply with the concerns of the administration responsible for approving the plan. Concurrently, the plan was discussed with the local community in order to provide an understanding of the requirements for getting the plan approved and the process of obtaining formal land titles. The plan includes expansions of the streets which will require some demolitions of built structures and concessions of land appropriated by the residents. The plan outlines zoning of future construction in the area, with four-story mixed-use row-houses adjacent to the local main street and two-story ‘twin-houses’ and detached houses in the rest of the plan. The project team suggested a plan including more rowhouses and higher densities, which was rejected by the municipal planners, who favored lower densities and open space between the buildings. Accordingly, the plan was amended, submitted, and has now been approved by the municipal authorities. Future workshops will support the community in completing and submitting applications for obtaining formal land titles. The first phase of the project is scheduled to conclude in 2021, and the project seeks to develop a larger scale intervention in Maxaquene D subsequently. On this basis, the project discusses issues such as insecure tenure, gentrification, and the right to the city.

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Pilot project area in Maxaquene D, 1:1000

Intervention street expansions and plot structure changes, 1:1000 Existing streets Street expansions Old plot boundaries

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New plot boundaries

Pilot project area in Maxaquene D, 1:1000

Maxaquene D intervention plan 1:1000 Regularized streets Plot boundaries

Two-story construction zone

Four-story construction zone

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Exhibition at the Royal Danish Academy Library

INFORMAL HORIZONS

Informal Horizons is a dissemination project on land rights and urban development in East Africa. The project included an exhibition and a book partially based on the practicebased work focusing on land titling in Maputo described in the previous section. Lack of formal land rights constitutes a major issue within urban development in East Africa, as it can lead to insecure tenure, forced evictions, as well as exclusion from public services, compromising sustainable development for millions of urban dwellers across the region. The project addressed these complex issues and highlighted a number of efforts to formalize land ownership through innovative solutions. The project was exhibited at the Royal Danish Academy Library and at Institute for (X) in Aarhus. The project was developed in collaboration with Anton Ryslinge, Margarida de Waco, and Anna Wahlén of Architects without Borders - Denmark. The dissemination project is titled Informal Horizons as the immediate future of East African cities is likely informal in terms of the primary type of urban development accommodating the majority of the urban population growth. Furthermore, many major cities in East Africa are characterized by vast peripheral informal settlements

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extending towards the horizon. The title of the publication and exhibition thus both refers to the physical structure of cities in the region and the likelihood of limited state regulation of future urban development. The project focused on current efforts to counter issues related to informal land ownership in East Africa, along with research on the underlying structures conditioning the informal urban growth. This included projects by the NGO, Architects without Borders - Denmark, addressing issues with land rights in Uganda and Mozambique. Informal Horizons sought to highlight a major issue in relation to the ongoing extensive urbanization processes in East Africa as well as showcase current attempts at transforming informal settlements into sustainable neighborhoods. The exhibition featured a condensed adaptation of the publication along with films and physical models. The material was displayed on an exhibition framework built of recycled plastic, referring to the plastic waste experiments in Maputo previously described in this chapter. The configuration of the exhibition framework emulated the spatial structures of informal settlements, thus providing visitors the experience of walking through the narrow alleys emblematic of such urban environments.

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Informal Horizons publication (2019)

Exhibition opening at the Royal Danish Academy Library (2019), photo by Jóannes B. Lamhauge Exhibition at the the Royal Danish Academy Library → 214

Interpositions publication (2019)

INTERPOSITIONS

Interpositions is a publication on the works of third-year architecture students attending the Royal Danish Academy. The research and practice-based work presented in this thesis was integrated in the education at the Institute of Architecture, Urbanism and Landscape. This involved organizing student fieldwork in the informal settlements of Maputo, Mozambique along with supervision of students developing projects in this context. The works of one of the groups of students were collected, curated, and presented in the publication Interpositions in 2019. The students produced the material presented in the publication during three weeks of fieldwork and subsequent three months of desktop work at the academy on their individual bachelor thesis projects, comprising community center designs in the informal settlement of Mafalala. The semester was organized in collaboration with Frederik Seehusen, Morten Meldgaard, and Knud Kappel. Mafalala is the most centrally located informal settlement in Maputo. The neighborhood is characterized by urban deficiencies such as substandard housing, lack of stormwater management systems, and overcrowding. The students engaged in discussions addressing the many challenges facing the neighborhood through architectural interventions. The community center assignment was quantified in several phases in order to highlight and examine specific issues. These phases included fieldwork, development of program, selection of site, artistic interpretations of the context, massing and volumetric studies, development of tectonics, project finalization, and presentation. The assignment was initiated with three weeks of fieldwork in Mafalala, in order to provide the necessary understanding of the context for developing the projects. The fieldwork included mapping of a common project area, surveys of individual houses, as well as hands-on design and construction work in Mafalala. After returning to the academy, the students defined the program of their

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projects, developed spatial diagrams, and produced abstract interpretations of the context. Subsequently, they did massing models in urban scale, along with detailed tectonic models. During this process, they focused on producing sitespecific readings of the urban context, cultivating building details, and developing original architectural syntaxes. Finally, the students produced detailed plans, sections, elevations, and 3D models, as well as presented their work in texts, drawings, and models. The assignment marked the culmination of the bachelor’s education preparing the students for professional practice in the field of architecture. Accordingly, the students applied a wide range of knowledge and skills within research and creative processes throughout the semester. This included both urban analyses and artistic experiments. The students developed design proposals for community centers with social, cultural, or civic programs. They developed the program for their projects independently and chose the exact sites within a common project area based on analysis of the context. Special emphasis was placed on the complex relationship between program, site, and building in the specific urban area. The students integrated aspects of architectural theory and building technology in the development of architectural concepts aiming at establishing a framework for public life in the neighborhood. During this process, the students discussed problems and themes relating to the UN Sustainable Development Goals such as education, job creation, and climate change. Interdisciplinary collaboration was an inherent theme throughout the semester, combining a research-based context-specific hands-on approach with an abstract and artistic approach to the architecture profession. Accordingly, the publication reflects upon cultural understanding, societal analysis, technical knowledge, and artistic processes, which underpin a holistic understanding of the architecture profession embodied in the work of the students.

Center for crafts and production by Lauritz Wagn Møller

↑ Context model showing a selection of student projects ↓ School for performance art by Lisa Xiaoli Zheng Minde

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Interpretation of public space usage by Lauritz Wagn Møller and Pernille Christensen

Street space survey by Lauritz Wagn Møller and Pernille Christensen

Part of urban scale survey of project area, 1:2000

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Plan 1:100

Architecture scale survey, 1:100

Section BB 1:100

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↑ Architectural interpretations of the urban structure reworked into floor plans of a library project by Annette Lindsetmo

Tectonic model by Lisa Xiaoli Zheng Minde →

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Conditions prior to intervention

Student sketch project

The fieldwork included a ‘hands-on’ workshop with local architecture students. The workshop sought to instrumentalize the knowledge of tectonics acquired during the architectural surveys as well as provide real-life experience with construction and its implications. Feeling the weight of a bag of cement on your own shoulders as well as experiencing the force needed to drill in concrete adds a level of comprehension of the construction process far

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from the highly digitalized work environment of the design studio. Furthermore, working in full scale demonstrates the importance of details and the basics of tectonics, inspirational for the subsequent design work. The workshop focused on problems with street encroachment in Mafalala. A local family who had appropriated part of the public space by setting up walls outside their plot boundaries was offered a new wall if they agreed to give back the street space to

Final project, plan/elevation

Completed project

the public. The students developed a multitude of design proposals, seeking to improve the quality of the public space. The sketch proposals were merged into a final project by the supervisors. The final design reinterprets the traditional local ‘baraza’ - a bench on the side of the street, marking the transition between public and private. The corrugated iron sheets from the old wall were reused and reclaimed tires filled with concrete were utilized as prefabricated

foundations. The design includes a window and an exterior table for selling vegetables. Per request from the family, the intervention included a new latrine in the back of the houses, improving the sanitary conditions for the residents. The workshop was organized in collaboration with Remígio Chilaule of FAPF, UEM.

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Workshop construction process, photos by Nelson Ilídio Cossa

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Casas Melhoradas, phase 2 (2015), multi-story housing prototype built of prefabricated timber elements

CASAS MELHORADAS

Casas Melhoradas is a project on alternative construction methods and new housing typologies in the informal settlements of Maputo, Mozambique. The project seeks to improve the quality and reduce the costs of housing through the development of alternative construction methods. Secondly, the project seeks to increase urban densities in the informal settlements through development of compact housing typologies. The project seeks to reach impact through the construction of demonstration houses which may be replicated by locals once the economic conditions for more widespread densification in the city develop. The project is carried out in collaboration with Jørgen Eskemose, Raul Machaieie, Architects without Borders – Denmark, and the Royal Danish Academy. The project has developed and built several housing prototypes in the informal settlements of Maputo. These include different concepts for vertical densification and alternative construction methods. This section summarizes the past project interventions, emphasizing the latest prototype constructed in 2018 along with the ongoing construction of a new prototype. Urban density in the informal settlements of Maputo Maputo is characterized by a high population growth rate (approximately 5% annually) and peripheral horizontal urban expansion, covering vast new areas with low urban density developments lacking appropriate infrastructure provision. Much of the recently developed settlements are far from

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the job opportunities in the center of the city, causing an increasing pressure on the land market in centrally located areas. The urban sprawl with low urban densities in the periphery of the city decreases mobility and increases the need for investments in infrastructure. Strategies for countering the extensive urban sprawl are thus essential for initiating a more sustainable urban development. There is limited experience with high densities in the informal settlements, as multi-story construction is expensive. However, increasing demand for centrally located land causes increasing prices, which provides the economic framework for urban densification through multi-story construction in the informal settlements. Consequently, informal multi-story structures have recently started to appear in the most centrally located informal settlements of Maputo. However, there are limited examples of multi-family multi-story low-cost housing. Almost all houses in the informal settlements are built without the involvement of the formal construction sector and virtually the entire construction process takes place on individual plots, leading to waste of resources as building materials often deteriorate during the lengthy process. Occasionally, families run out of money during the construction process, leaving half-finished uninhabited structures. There is a limited degree of industrialization in the construction sector and the quality of construction is often low.

Casas Melhoradas, phase 2 (2015)

Casas Melhoradas, phase 3 (2016), vertical addition to old house

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Casas Melhoradas, phase 4 (2018), compact housing prototype built of compressed earth blocks

Project The project develops alternative housing models in order to examine different modes of vertical densification. Thereby, the project seeks to investigate appropriate compact housing typologies for accommodating the future urban growth of the city. The project has tested different concepts such as vertical expansions of existing houses, common courtyards with shared toilet and shower facilities, and outdoor kitchens on balconies as charcoal is often used for cooking. Thereby, the project seeks to demonstrate new models for compact city development and inspire local residents to build more dense and utilize the space more economically. On this basis, the project seeks to address issues with mobility and make future infrastructure investments more cost-effective. Secondly, the project tests alternative construction methods seeking to reduce costs and improve the quality of housing. The project has tested pre-fabrication of light-weight timber elements produced in a local carpentry workshop. These elements were subsequently transported by hand and assembled into a complete house in a relatively short time,

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without the use of heavy machinery. Additionally, the project has tested alternative construction materials with low carbon footprints in order to decrease the environmental impact of construction. This includes sustainably produced timber as well as compressed earth block construction. The project is currently testing production techniques utilizing plastic waste as a construction material linked to the plastic waste experiments previously described in this chapter. The developed housing models and construction techniques are tested in full scale in collaboration with local builders, through construction of demonstration houses which are subsequently evaluated in order to identify the most appropriate solutions for low-income groups in Maputo. The constructed houses are rented out to local families through the registered company Casas Melhoradas ltd and the generated income is reinvested in construction of new housing units.

Casas Melhoradas, phase 4, outdoor kitchen

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Section AA, 1:200

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Transport of construction materials

Prefabrication of timber elements

Transportation of prefabricated elements

Prefabricated elements are organized at construction site

Prefabricated structural system for concrete slab

Prefabrication of timber elements

Prefabricated elements are assembled

Prefabricated elements assembled

Compressed earth block wall

Prefabricated system for concrete slab

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Casas Melhoradas publication (2018)

Phase 4 of the project was completed in 2018. It demonstrates a new model for low-rise, high-density row-house typologies. The project includes six dwellings on a plot where there would otherwise reside a single family. Accordingly, the project demonstrates how space and infrastructure can be used more economically. All the dwellings have small private outdoor areas with kitchens, as charcoal is the primary fuel for cooking. The project includes small common courtyards with shared bathrooms and laundry facilities. The project has a green roof where an additional floor can be added, which ensures the project robustness in relation to the future urban development. Furthermore, the evaporation from the roof improves the indoor climate by cooling the dwellings. The project was built of compressed earth blocks, reducing the energy consumption in the construction process while adding the same red color tone of the local soil to the walls.

Phase 5 of the project was initiated in 2019. It was delayed due to the COVID-19 pandemic but the construction is scheduled to be completed in 2021. The project demonstrates a new model for low-rise, high-density court-yard housing typologies. The project includes four dwellings on a single-family plot as well as a shared courtyard with an old mango tree and balconies with kitchens. The design features a green recreational roof terrace, including concepts for rainwater harvesting and a kitchen garden built of recycled plastic beams. The design includes wires stretched diagonally across the facades where creepers can grow. The project thus demonstrates new approaches to densifying the city, increasing biodiversity, and improving the microclimate. These housing prototypes discuss central themes related to the ongoing extensive urban development in the region, such as compact city development, construction techniques, and livelihood.

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↑ Film screening at CAFx Film festival at Cinemateket (2019), photo by Francesco Martello

BORN AND RAISED IN THE GHETTO

Born and Raised in the Ghetto is an award-winning threepart documentary mini-series about urban life in informal settlements in sub-Saharan Africa. Each film portrays a neighborhood, focusing on the urban characteristics, everyday life, and some of the emblematic problems linked to informal urban development. The films follow a young local man in each location who presents his neighborhood in his own words. The three local men have structured lives, pride and aspirations. Thereby, the films challenge the way residents of informal settlements are commonly conceptualized in the media. The films thus seek to provide a nuanced portrait of the three neighborhoods and their residents with a focus on both problems and potentials. Sub-Saharan Africa is one of the least urbanized parts of the world. However, the region has some of the highest population growth rates and rates of urbanization. Consequently, African cities are undergoing radical urban transformations in order to accommodate the rapidly growing population. More than half of the urban population in Africa resides in informal settlements under precarious conditions. However, most residents live relatively normal lives and take pride in their homes and neighborhoods. While the negative associations of informal settlements are manifested in real problems, very few people have an idea of their actual implications. The stereotypes of a primitive Africa

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Film series poster →

conveyed by the media are often far from the hyper-urban reality that characterizes most African cities. This documentary series takes a unique look at the conditions of some of the most extreme urban environments in the world with heartwarming personal stories and new perspectives on urban development in Africa. The films were shot with a hand-held smart camera without zoom or manual focus. Accordingly, the films have a no-nonsense stripped-down visual style, similar to the personal experience of walking through these urban areas. Aesthetically, the series thereby relates to the African smart-phone generation, mediating the artistic expression and media format prevalent among young urban dwellers across the continent. The mini-series was included in the official selection of a long list of film festivals, including CAFx - Copenhagen Architecture Festival, Cinema Urbana, and Kugoma Mozambican Film Forum. The mini-series won the award for Best TV Episodic Series at the Impact Humanity Television and Film Festival (2019) as well as the award for best documentary at ASIFF – African Smartphone International Festival (2018). The full documentary series is available at www.filmstriben.dk and the trailer for the series is accessible at https://vimeo.com/278821131

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Born and Raised in the Ghetto still frames

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Model of project area in Mafalala

MAFALALA FUTURES

Mafalala Futures is an architectural debate project focusing on the future development of informal settlements in Maputo, Mozambique and the wider African context. The project outlines three possible future urban development scenarios for the same area in Maputo based on different positions in urban planning discourse. Thereby the project discusses the spatial qualities and the urban deficiencies of different possible future scenarios. The project was developed in collaboration with Remígio Chilaule and supported by Iverca. The material was exhibited on several occasions and published in the book Futuros da Mafalala / Mafalala Futures.

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Plot structure and public space

Africa is urbanizing at a rapid pace and the majority of the urban development is informal. There are few examples of successful development of informal urban areas. Mafalala Futures discusses problems associated with lack of public interventions in informal settlements and public approaches to redevelopment of such urban areas. Finally, the project outlines possible ways to develop informal settlements into sustainable urban neighborhoods, adequate for the socio-cultural norms that define these areas. The project sought to inspire and provoke discussions contributing to the innovation of adequate models for urban design, housing typologies, and urban development strategies for informal settlements which is vital for the future of African cities.

Project area in Mafalala

Project area in Mafalala, 100x100m

Historical architecture in project area

Mafalala is the most centrally located informal settlement in Maputo, Mozambique. The neighborhood was the cultural and political center of the Mozambican liberation struggle against the Portuguese colonial rule. The area is famous for being home to renowned artists, world-class football players, and leading politicians, who played a crucial role in the formation of the country and the national identity. Mafalala is known for its distinctive cultural heritage, with many significant corrugated iron sheet houses dating back to the 1930s. This includes the house of the country’s first president, Samora Machel. However, the historical cultural heritage is deteriorating due to the limited resources for maintenance of the buildings.

Mafalala Futures presents three hypothetical future scenarios for the urban development of the same 100x100m area in Mafalala. Each scenario was inspired by examples of urban design from Madagascar, South Africa, and Mozambique. All three scenarios have the same urban density and would thus be able to accommodate a comparable number of residents while having completely different urban forms and spatial qualities. As the quantitative measured urban density is the same in all three cases, the qualitative comparison becomes apparent, illuminating the spatial qualities and deficiencies of each scenario.

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Model of scenario #1

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Model of scenario #1

Plot structure and public space

Scenario #1: No intervention is based on the current development where the neighborhood continues to densify without enforcement of regulation or large-scale government intervention. This is perhaps the most likely future scenario, as there is no history in Maputo for large-scale forced evictions and redevelopment of the informal urban areas. In this scenario, the public space is gradually privatized through encroachment on the streets. The only public square in the area is privatized and occupied with buildings. The cultural heritage is disregarded and new buildings replace the historical ‘Casas de Madeira e Zinco’ (corrugated iron sheet houses). Almost all trees are cut down to make space for new buildings. The increasing urban density leads to undesirable

living conditions as many of the houses have inadequate access to natural light and air. The problems with lack of public infrastructure such as sewage and stormwater management systems are amplified due to increased building coverage, decreased proportion of public space, and increased number of residents. Accordingly, the risk of fire and spread of waterborne diseases is increased. While the spatially intriguing urban growth may seem appealing, it has widespread negative implications for the residents. The scenario was inspired by unregulated urban areas, such as Antohomadinika in Antananarivo, the capital of the neighboring country, Madagascar.

Reference area in Antananarivo, Madagascar

Reference area in Antananarivo, Madagascar, 100x100m

Reference area in Antananarivo, Madagascar

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Model of scenario #2

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Model of scenario #2

Plot structure and public space

Scenario #2: Extreme intervention is based on conventional ‘slum upgrade’ strategies known from other African countries such as South Africa and Kenya. In this scenario, all residents are evicted from their houses and resettled in newly constructed tower blocks. These large-scale housing typologies are relatively low cost, with one staircase serving up to 12 dwellings per floor. The new blocks are all four stories and constructed without elevators, in accordance to the Mozambican building code to lower the cost. The historic buildings are demolished and most trees are cut down and replaced by newly planted trees that do not offer the same qualities of shade, diversity, and heritage. The urban design is based on cars as the main mode of transportation. While there is more public space in this scenario compared to the other scenarios, it is hard to see the spatial qualities, leaving limited options for potential social life. Shops, hair salons,

and bars are not integrated in the plan layout as the buildings are disassociated from the streets. Consequently, informal small-scale construction reemerges to provide these essential functions to the neighborhood and new modes of informal construction appear between the large-scale blocks. This top-down intervention does not comply with the cultural norms of the residents, for which the uniform large-scale architecture, wide street spaces, and formal urban design seem foreign. Accordingly, it is easy to imagine that problems of social isolation, crime in the deserted streets, and lack of safety for kids playing because of the car-based urban design characterizing the area. This scenario is inspired by areas targeted for ‘slum upgrade’ projects, such as Alexandra in Johannesburg, the largest city of the neighboring country, South Africa.

Reference area in Johannesburg, South Africa

Reference area in Johannesburg, South Africa, 100x100m

Reference area in Johannesburg, South Africa

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Model of scenario #3

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Model of scenario #3

Plot structure and public space

Scenario #3: Context aware intervention is based on a gradual development of the area, acknowledging the spatial qualities and cultural heritage of the area. The neighborhood is transformed block by block, preserving the overall structure of the neighborhood. The streets are assessed case by case and widened according to the requirements and possibilities, allowing access for cars and public service vehicles, such as garbage trucks and ambulances as well as implementation of new infrastructure. Some of the smaller alleys are preserved as pedestrian shortcuts between the mainly one-way streets, based on shared space principles. The residents are gradually resettled in diversified low-rise, high-density housing typologies, providing a multitude of different types of dwellings allowing for a diverse occupation pattern based on specific economic and social circumstances.

This typological diversity adds a new layer to the neighborhood, which today is largely characterized by single-story detached housing typologies and few multifamily dwellings. The urban design includes a variety of different spatial qualities accommodating heterogeneous expressions of social life, relating to the existing spatial diversity of informal settlements. The historic buildings and larger trees are preserved as these constitute qualities of the area and have the potential to maintain the tourism relating to the neighborhood’s cultural and historical heritage. The urban design seeks to enhance the intimate social structure of informal settlements while recognizing the inherent qualities already characterizing the neighborhood. The scenario was inspired by low-rise high-density urban areas, such as Alto Maé and Chamanculo A in Maputo.

Reference area in Maputo, Mozambique

Reference area in Maputo, Mozambique, 100x100m

Reference area in Maputo, Mozambique

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Exhibition opening in Mafalala (2018)

Mafalala Futures was exhibited at Lima’s Bar in Mafalala in June 2018. The opening of the exhibition included a presentation outlining the thoughts behind the project. Community leaders, local residents, municipal planners, public authorities, and local architecture and planning professionals participated in the event which sparked a much-appreciated debate about urban planning, housing, and urban development strategies for informal settlements in Maputo and the wider sub-Saharan African context. The project was later exhibited at Centro Cultural Franco Moçambicano. The exhibition was set up in a corner with two parallel walls forming a narrow alley providing access to

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an enclosed space full of prints and models. The exhibition setup thereby emulated the alleys typical of Mafalala. A book containing the entire exhibition material and a more in-depth discussion was published in November 2018 and launched at Fundação Fernando Leite Couto as a part of the Maputo Fast Forward festival. Finally, the material was featured in the opening exhibition of Museu Mafalala in which two former presidents of the country participated. The majority of the extensive urban population growth in sub-Saharan Africa will likely continue to be accommodated through proliferation of informal urban development.

Mafalala Futures publication (2018)

While numerous efforts are made to counter the negative implications of these trends, the examples of successful development of informal settlements into sustainable neighborhoods are limited. The notion of ‘slum upgrade’ programs seems misunderstood and the architectural models that replace the informal urban areas seem inappropriate for the cultural norms defining the informal settlements. Shortsighted economic considerations and hidebound perceptions of informal urban areas seem to drive much decision-making. Accordingly, innovation of adequate models of urban design, housing typologies, and urban development strategies for sustainable development of informal settlements is vital for the future of African cities.

The presented scenarios are conceptual expressions of different frameworks for the development of informal settlements rather than actual project proposals to be implemented. Accordingly, the project sought to initiate a public conversation on the future development of informal settlements rather than presenting realistic pragmatic project proposals. The development of adequate urban design models for informal settlements is too important to be left to architects. Consequently, the process needs involvement from policy-makers, community-based organizations, investors, and urban devleopment professionals in the broadest sense in order to enhance the sustainable development of informal settlements in sub-Saharan Africa.

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Exhibition at Centro Cultural Franco Moçambicano (2018)

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PART IV: CONCLUSION

This section synthesizes the key findings of the PhD thesis, assesses the implications of the research, and summarizes the policy recommendations outlined in the research papers. Additionally, the section includes reflections on the practicebased work presented in Part III and on future studies on urban morphology of informal settlements in sub-Saharan Africa. Finally, the section provides a critique of different positions adopted in the research and discusses appropriate approaches to urban morphology research, spatial planning, and architecture.

THEORETICAL CONTRIBUTIONS

This section summarizes the theoretical contributions of the research papers. Perhaps most notably, these include the ‘informal land supply hypothesis’, the concept of ‘collective investment capacity’, and the concept of ‘relative centrality’. Furthermore, the findings in relation to urban densification, the impact of urban planning, the impact of local governance structures, and development of urban tree canopy cover in informal settlements in East Africa highlight new knowledge on cities in the region. The most significant theoretical contribution developed throughout the work on this thesis is perhaps the ‘informal land supply hypothesis’ first described in Mottelson & Venerandi (2020) and later further developed and supported with additional empirical evidence in Mottelson (2020). The hypothesis outlines a model for understanding informal urban development in cities characterized by high population growth rates and urban majorities financially excluded from the formal housing markets. More specifically, the hypothesis suggests that government attitudes towards informal urban development decisively influence the urban form and the livelihood in informal settlements. It suggests that government repression of informal urban development decreases informal land supply and leads to increased competition in the informal land market, causing higher costs of accommodation and consequent fewer resources for investments in household infrastructure (e.g., water, sanitation, and electricity) and thereby more compromised livelihood. In parallel, it suggests that the higher population densities on the informal land in cities with limited informal land supply leads to a higher concentration of resources for built densification through the increased ‘collective investment capacity’. The hypothesis consists of three hierarchical layers. First, the governance practice decisively influences the informal land supply. Second, market mechanisms influence the price of informal land. Third, the price of informal land influences household conditions and the development of the urban form. This hypothesis is limited to cities with large populations financially excluded from the formal housing market and limited state capacity to administer urban development. However, such conditions are widespread in large cities throughout sub-Saharan Africa.

The spatial extent of the informal urban areas varies greatly from country to country and from city to city in East Africa. In Nairobi, authorities adopt policies of evicting residents of informal settlements due to the extra-legal conditions of construction without permits and lack of land titles (Talukdar, 2018). In Maputo, governments grant some property rights protecting the residents of informal settlements along with a de facto acceptance of the extra-legal practice to a greater extent (Jenkins, 2013). This is exemplified by the spatial extent of informal settlements in Maputo, Mozambique and Nairobi, Kenya presented on page 263. More specifically, the share of informal land use is almost 30 times as high in Maputo compared with Nairobi. Government repression of informal urban development decreases informal land supply, confining the space attainable for the poor majorities and leading to higher population densities within the informal landmass. Conversely, government acceptance or negligence of the proliferation of informal urban development increases informal land supply and thus provides more space for those excluded from the formal landmarket, leading to lower population densities of the informal landmass. Government attitudes towards informal urban development, as well as the capacity to control it, will thus decisively influence the population densities of these areas. In the informal settlements in Nairobi, household conditions are characterized by low levels of access to water and sanitation, high levels of overcrowding, and a high proportion of tenants (Gulyani et al., 2012; Gulyani & Talukdar, 2008; Marx et al., 2013; O’Keefe et al., 2015). In the informal settlements in Maputo, household conditions are characterized by high levels of access to water and sanitation, low levels of overcrowding, and a low proportion of tenants (Forjaz et al., 2006; Holcomb et al., 2020; Jenkins, 2013; Peal et al., 2014). Surveys of a case study area in each city found higher levels of built density in the case in Nairobi compared to the case in Maputo even though the case study area in Nairobi is less centrally located (Mottelson & Venerandi, 2020). Both Kenya and Mozambique are characterized by high population growth rates, low national GDP per capita, and high rates of urbanization. Both Nairobi and Maputo are characterized by large populations and urban poor majorities financially excluded from the formal housing market (UN-Habitat, 2013). Accordingly, the demand for informal land in both cities is likely high in both cities. Mozambique has a lower GDP per capita compared to Kenya. Accordingly, GDP per capita cannot account for the more compromized household conditions seen in Nairobi. Geographic factors, such as mountains, lakes, and the sea, may influence the total landmass available for urban development in any given city and thereby also influence the size of informal landmass. The center of Maputo is located at the tip of a peninsula and large parts of the municipal landmass were inaccessible at the time of the informal land use survey presented in the Alley in Mafalala, Maputo, Mozambique →

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1 Governance restriction of informal urban development

Governance acquiescence of informal urban development

Decreased informal land-supply

Increased informal land-supply

Increased competition on the informal land market

Decreased competition on the informal land market

Increased costs of land

Decreased costs of land

Increased costs of accomodation

Decreased costs of accomodation

Increased share of tenants

Increased share of household economy spent on accommodation

Hihger investment capacity of land holders

Decreased share of tenants

Decreased share of household economy spent on accommodation

Lower investment capacity of land holders

3 More compact urban form of informal settlements

Compromized livelihood

Less compact urban form of informal settlements

Improved livelihood

Graphical representation of the ‘Informal land supply hypothesis’

figure on page 263 as it was conducted before the construction of the new bridge which provides better access to Katembe (the area south of the bay). The urban development in Nairobi is not conditioned by geographic constraints to the same extent. Consequently, geographic factors likely curb informal urban development in Maputo to a higher extent than in Nairobi, yet informal urban development is much more widespread in Maputo. Accordingly, geographic factors cannot account for the variations in informal urban land use. Nairobi has a higher total urban population compared to Maputo which may lead to an increased demand for housing in informal settlements in the city and thereby higher costs of accommodation. This may partially account for the variations in built densities and livelihood. However, Dar es Salaam is a larger city than Nairobi, and similar conditions to Maputo are seen in this city in terms of livelihood, informal land use and built densities (Mottelson, 2020a). As demonstrated, factors such as neighborhood centrality, total urban population size, GDP per capita, and geography cannot account for the differences between Maputo and Nairobi in terms of household conditions. On this basis, the ‘informal land supply hypothesis’ suggests that the level of government control of the land market is the primary driver of the differences in informal land use, the urban density, and the household conditions in these two cities. 262

The formal–informal price gap reflects a spatial equilibrium, in which the lower land prices in informal settlements are offset by a lack of property rights and consequent lack of tenure security. As tenure security represents an important amenity, the formal–informal market value of land differs significantly. This price difference excludes the urban poor from owning formal land. If simple supply and demand mechanisms influence the cost of informal land, government attitudes and practices towards informal urban development influence the informal land supply and thereby land prices. More specifically, government restriction of informal urban development will decrease informal land supply and thereby increase the competition in the informal land market, resulting in increased costs of land and accommodation in the informal market. Conversely, government acquiescence to the proliferation of informal urban development will increase informal land supply, and thereby decrease competition in the informal land market, resulting in the decreased price of land and accommodation in the informal market. Angel (2000) provides a similar argument, namely that greenbelt policies increase the costs of affordable housing due to containment of urban expansion and consequent decreased land supply, resulting in increased competition and higher costs of accommodation. Consequently, government restriction of informal urban development through forced evictions decreases the

Maputo, Mozambique

Informal settlement Road Municipal Boundary Sea 0

Nairobi, Kenya 10 km

The spatial extent of informal settlements in Maputo, Mozambique and Nairobi, Kenya 263

informal land supply and thus leads to increased costs of accommodation. Government restriction of informal urban development and consequent increasing costs of informal land further exclude the least wealthy parts of the population from holding land and thereby lead to an increased proportion of tenants. This mechanism is underpinned by the fragmented and limited informal urban land use, the high proportion of tenants, and the high cost of accommodation seen in Nairobi, and conversely by the continuous informal urban land use, the lower proportion of tenants, and lower costs of accommodation seen in Maputo. The hypothesis suggests that the decreased informal land supply leads to increased competition in the informal land market resulting in higher costs of accommodation in cities such as Nairobi. The higher costs of accommodation lead to fewer resources for other basic necessities. The hypothesis suggests that this explains the more widespread compromised livelihood in Nairobi. The higher concentration of people and the rent-based income for landholders increase the collective investment capacity for densification in cities with limited informal land supply. This may account for the higher built densities seen in informal settlements in Nairobi compared to Maputo. Accordingly, the hypothesis suggests that the government approach to informal urban development condition the market mechanisms which influence the costs of accommodation and thereby condition outcomes in livelihood and urban density. Mainstream urban economic theory emphasizes the importance of transportation in relation to the development of urban form. The ‘informal land supply hypothesis’ adds novel nuances to these theories by underscoring that the attitude of the government towards informal urban development in cities where the majority is financially excluded from the formal housing market is significant for understanding the urban morphology of informal settlements. The concept of ‘collective investment capacity’ is linked to the notion of housing supply elasticity. Generally, housing supply is slow to catch up with fluctuations in demand as it takes time to build new houses. In the context of informal settlements, construction is not financed through formal financial institutions due to the extra-legal conditions of the landownership and consequent lack of access to financial services as informal land cannot be used as collateral for obtaining bank loans. Construction in informal settlements is thus largely dependent on the private savings of the landholders. In settlements with low population densities and few tenants, the collective resources for investments are limited. This constrains the potential for built densification. As overcrowding is common in informal settlements, expansion of dwellings is typically desired. However, built densification is largely constrained by the limited household economy. Consequently, households in informal settlements typically develop incrementally when economic resources for expansion are available (Andersen et al., 2015b). In informal settlements with low population densities, household densities are typically also low, and the resources for densification are limited. The concept of ‘collective investment capacity’ refers to this relationship between household densities and the potential for built densification.

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As informal settlements densify over time, built densities reflect the collective accumulated resources invested in home expansions (Mottelson, 2020b). Consequently, the time of the establishment of the settlement will likely impact the development of the densities, in part because of the limited investment capacity for built densification. However, this has not been studied in detail yet. The population densities in informal urban areas are an outcome of the size of the population financially excluded from the formal housing market and the total area of the informal urban land use. Limited informal urban land use and large populations financially excluded from the formal housing market thus result in high population densities. The higher population densities in informal settlements in cities with limited informal land supply and large populations financially excluded from the formal housing may provide an increased accumulative collective investment capacity of high-density populations and thereby contribute to the higher built densities. In areas with high proportions of tenants, landholders likely have more resources for densification as they receive rent from the tenants. This may further contribute to the higher built densities in such areas. Furthermore, the economic incentives for landlords to optimize the use of space may lead to more compact urban form in areas with a high proportion of tenants (Mottelson, 2020a). Accordingly, population density, the income of the residents, the temporal conditions of the establishment of settlements, and tenancy are important determinants for the development of urban form of informal settlements. Urban economists highlight the significance of centrality in relation to land prices and built densities due to the transportation costs to reach the city center (Glaeser, 2020). The value of amenities has been investigated in numerous studies (Smith, 1978). However, studies of the formalinformal land price gab remain scarce. As formal property rights protect the rights of landowners to the land and thereby secures the investments in construction on said land, formal land titles constitute important amenities. Accordingly, the built densities of informal settlements are arguably not only determined by the transportation costs according to the absolute centrality but determined by the volume of informal land in the city and the relative centrality within the informal land market. The centrality of informal settlements should thus be considered in relation to the remaining informal urban areas and not in absolute centrality measures as the informal land market exists in parallel with the formal land market. In cities where the majority is excluded from the formal land market and the government restricts informal urban development in centrally located areas, the most centrally located informal area will likely be dense irrespective of absolute centrality measures, as it is the most centrally located affordable area for the population excluded from the formal housing market. The notion of ‘relative centrality’ thus refers to the centrality of an informal urban area in relation to the remaining informal urban area of the city. This may explain that formal and informal neighborhoods with comparable centrality display large variations in built densities such as urban poor residing in dense overcrowded informal settlements next to suburban

detached housing areas. This is exemplified in Nairobi, where peripheral informal settlements are characterized by built densities exceeding parts of the CBD adjacent to suburban low-density formal neighborhoods. Accordingly, the relative centrality within the informal landmarket is likely more important to consider rather than absolute centrality measures when assessing the urban form of informal settlements. These concepts were developed based on the findings of this thesis and constitute contributions to the body of theories on how cities in developing countries develop. However, the research project also found a number of more specific results on the development of informal settlements. The longitudinal studies of informal settlements in Maputo suggest that the more centrally located informal settlements are characterized by decreasing population densities and the urban growth is accommodated through urban expansion which may occur at the expense of ecosystems while exacerbating problems with mobility and infrastructure provision (Jenkins & Mottelson, 2020; Mottelson, 2020b). Furthermore, these studies suggest that informal settlements densify over time and that the built densification leads to decreased urban tree canopy cover. The comparative study of informal settlements in major cities in East Africa suggests that the public space ratio in informal settlements is linked to block sizes and that built densities and the public space ratio are not interdependent (Mottelson, 2020a). The comparative study of planned and unplanned settlements in Maputo, Mozambique found that planning has a significant long-term impact on urban form and built densities despite the lack of enforcement of urban regulation (Mottelson, 2021). The study furthermore suggests that the governance practices of local administrations play a crucial role in regulating the levels of street encroachment and are thus essential in addressing the issues associated with unregulated urban development. As these findings reveal important aspects of how informal settlements develop the policy implications are arguably significant.

POLICY RECOMMENDATIONS

This section outlines a number of proposals based on the empirical studies presented in Part II. In general, detailed land use plans are arguably inadequate in guiding urban development as the institutional capacity to enforce such regulation is inadequate in most major cities in East Africa. Consequently, these recommendations rely on alternative measures to control the urban development. These policy proposals include anti-eviction laws, development of new tenure forms with less strict application of the building code, provision of small plots on government-owned land, early implementation of robust street networks in peripheral settlements, road-pricing, upgrading infrastructure in dense settlements, innovation in surveying and land use management methods, strategic use of construction of dense affordable housing as compensation for the relocation of population, and provision of additional mandate for decision-making along with additional resources for local administrations.

The ‘informal land supply hypothesis’ suggests that restriction of informal urban development in major cities in sub-Saharan Africa results in compromised livelihood for large parts of the population. Accordingly, the policy implications may be significant if decision-makers consider improved livelihood a political goal. Evictions are not a sustainable solution to the proliferation of informal settlements as most residents of informal settlements cannot afford housing within the formal market. Furthermore, evictions lead to increased costs of rental housing due to the price-premium paid by tenants for the increased risk of lost investments for the landlords. Accordingly, forced evictions without adequate compensation do not solve the fundamental issues and may in fact lead to worse conditions for the urban poor. Anti-eviction laws may thus be advised in order to increase tenure security. Such laws may include a due notice for landowners to inform land users, negotiation for the terms of compensations, requirement of relocation, minimum requirements for the period of occupation before rights are ensured, and financial assistance for relocation. Compliance with the building code and application of the formal procedures of land management lead to increased costs for the land users. Furthermore, the administrative capacity of the public sectors to process the legal framework for formal urban development is inadequate in most major cities in the region (UN-Habitat, 2010). Accordingly, there is a need to decrease the costs of complying with regulation for the land users as well as a need to decrease the bureaucratic workload of urban land management for authorities. Some countries recognize that the residents were not able to comply with the regulation or that the limited administrative capacity of the state did not provide viable alternatives to informal housing during the time of the establishment of the informal settlements (Jenkins, 2013). Consequently, these countries already grant some land rights to residents of informal settlements. Such rights include protection from uncompensated forced evictions and a legal path towards formalization. A new category of tenure may be developed in order to provide rights to informal landholders and provide a higher degree of tenure security. This informal landholder title may be governed with less costly requirements for spatial surveys and less strict application of the building code. More specifically, urban development may be guided with simple zoning plans permitting informal construction within certain spatial frameworks of plots. This may include standardized setbacks from access routes and maximum building heights. Such zoning could be administered by the local authorities in the informal settlements without the involvement of high-salary technical professionals. This would likely improve the conditions for provision of legal and affordable housing under market conditions as it would remove some of the administrative and cost-increasing barriers of the current legal housing market. Accordingly, it would provide legal protection from eviction for the residents of informal settlements and provide more viable guidelines countering hazardous densification of such areas.

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KENSUP housing project →

Upgraded The uniform newly constructed eight-story tower blocks with paved common courtyards and raised pedestrian access decks are in striking contrast to the intimate muddy alleys in the surrounding low-rise high-density settlements. The ‘slum upgrade’ resettlement scheme conveys a Corbusian perspective on Kibera. Are these bright naturally ventilated apartments with running water and flushing toilets ‘machines for living’ which address the unsanitary and unhealthy conditions of the slum? Or will they become the slum of tomorrow characterized by social isolation, substance abuse, and vandalism? Today, some resettled tenants have started subletting their dwellings to middle-class citizens and moved back into the informal parts of Kibera with a supplementary income as the rent was set below market value. Who knows what the future holds? 266

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Governments may consider designating new areas for construction without strict application of the building code in order to increase the supply of affordable land and thereby reduce the price on the market. This could be pioneered through state-financed allocation of small plots with leasehold titles on government-owned land, with allocation of sufficient street space, common water and sanitation units, and local guidance for auto-construction without strict enforcement of the building code. The local administration of these areas may receive capacity building in the urban management to provide general guidelines for the informal construction according to basic zoning such as maximum building heights and setbacks from access routes. Appropriate solutions for such pilot areas may include minimal plot sizes (e.g., 100m2), on which the citizens construct their houses guided by the local administration. Common bathrooms, showers, and water posts may be public-funded to provide infrastructure for those who cannot afford the solutions provided by the market. This will likely decrease the competition on the informal land market resulting in lower costs of accommodation and thereby free resources for investments in basic household infrastructure (e.g., water, sanitation, and electricity) and lead to improved livelihood. Previous studies have shown that the cost of structural adjustment of the urban fabric of informal settlements is much more expensive than ‘greenfield’ developments (Lamson-Hall et al., 2019). Accordingly, if efforts to regularize peripheral areas are postponed, the urban form will consolidate and the costs of such interventions will increase. Mottelson (2021) suggests that urban planning has a significant impact on the development of the urban form of informal settlements. More specifically, informal urban areas that were planned more than 40 years ago are characterized by significantly higher levels of public space, larger average street widths, and higher built densities compared to adjacent unplanned informal sample areas. Urban planning thus likely leads to increased feasibility and cost-effectiveness of implementation infrastructure due to the higher level of public space and higher average street width. Additionally, urban planning may have positive effects on mobility due to the higher built densities and likely higher population densities in the planned areas. Consequently, urban planning is suggested to have a significant long-term impact even in contexts with limited institutional capacity to enforce urban regulation. This underpins the significance of allocation of public funds for the provision of spatial planning, particularly in peripheral areas where the urban form is not consolidated yet as implementation of planned urban structures in such areas will be less costly. Accordingly, efforts to implement robust urban structures in peripheral areas should be considered a policy priority. Small and narrow plots should be advocated in this process as this will enable higher population densities and thereby limit the urban expansion, lower costs of individual plots, and increase the costeffectiveness of future investments in infrastructure. Plot dimensions as small as 5x10 m could be tested in order to advance compact city development and attain affordability.

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Major roads are suggested in two-kilometer grids as this will provide access to public transportation within 10 minutes for pedestrians and thereby improve mobility. Mottelson (2020a, 2021) suggests that the local neighborhood administrations to a large extent manage the urban development of informal settlements and play a crucial role in countering street encroachment and maintaining the public space. However, much of this de facto local governance of the urban development occurs without a legal basis. Accordingly, the legal guidelines for the mandate of this governance practice may be subject to revision. In order to formalize such practices, local administrations may thus acquire additional mandates for such local governance. This could include the authority to issue construction permits based on basic requirements such as maximum building heights and setbacks from access routes. Liability for the security of construction may be the responsibility of either the landholder/owner or the contractor. Standardized contracts for this may be managed locally. Furthermore, the local administrations may be provided capacity building in urban management in order to counter issues with hazardous densification. Finally, additional resources for enhancing local priorities such as street expansions or infrastructure provision may be provided to the local administrations. Particularly in areas characterized by issues with public hygiene, local administrations may need technical support in street expansions and implementing stormwater management infrastructure. Such increased mandate for governance and decision making along with more resources for locally decided infrastructure priorities may thus address issues with hazardous densification and street encroach as well as provide more viable legal frameworks for urban development based on the local resources. The likelihood of continued lack of state control of the peripheral urban development will likely result in continued urban expansion and consequent unsustainable resource consumption as well as exacerbated issues with mobility in many sub-Saharan African cities. In such cases, road pricing could be considered for accessing more central parts of the cities in order to generate public revenue, decrease traffic congestion, decrease CO2 emissions, and curb the urban expansion. According to the ‘cost of friction hypothesis’, increased transportation costs will result in increased incentives for densification in central areas. This may create a market based ‘green-belt’ effect, which would otherwise require land management capacities that local authorities lack. Exemption of public transport for the road pricing may ensure a more socially balanced urban development. This may provide incentives for the middle class who can afford investments in infrastructure to settle within these central areas for driving the urban densification and thereby limit issues with public hygiene in more dense settlements. Furthermore, property taxes are not collected in informal settlements due to the extra-legal conditions. In Maputo, there is a monthly tax on access to electricity which is de facto comparable to property taxation. Alternative measures for collection of public revenue such as road-pricing or

taxation of electricity may provide the resources for investing in establishing peripheral roads before the urban form consolidates or improve the public hygiene conditions in centrally located dense informal settlements. Accordingly, road-pricing may curb the urban expansion, improve the conditions for sustainable densification, and generate public revenue for investments in infrastructure. As the formal housing market is incapable of providing affordable legal housing for the majority of the urban population in East Africa, state-subsidized alternatives may seem like a viable solution in addressing the proliferation of informal settlements. However, public housing programs in the region have shown ambiguous results. Issues with lack of affordability, access to the housing units through bribery, and residents moving back into informal settlements while subletting out the apartments to middle-class tenants have been reported (Ndungu, 2012). Furthermore, governments in the region lack the necessary funding to construct housing at a scale corresponding to the enormous demand (Jenkins & Mottelson, 2020). Accordingly, state-subsidized housing is likely not a viable solution for the urban majority residing in informal settlements as the economic resources for such programs are not available or not politically viable. Consequently, state-subsidized housing may rather be considered a strategic tool used for increasing mobility and addressing issues of public hygiene. Implementation of new roads and stormwater management systems often requires relocation of population in order to expand street spaces and implement new streets. Construction of high-density public housing units in well-connected areas could thus be used as compensation for the relocation of residents of informal settlements in relation to implementation of such infrastructure. However, unless policy priorities are significantly changed or economic resources in the public sectors are significantly increased, social housing will likely remain limited to a strategic tool rather than a broad housing solution for those currently excluded from the formal housing market in East Africa. Technological development has brought low-cost survey solutions with drones and community mapping with smartphones. Innovation in this field may advance affordable land use management solutions utilizing drones, apps, and smartphones to provide new forms of geo-surveys of landmarks, built structures, plot boundaries, and street space. This could include automatically generated guidance based on inputs given to an app according to basic zoning requirements for informal construction described previously in this section. Such systems may be developed and tried as tools to address the negative consequences of lack of urban regulation without the added costs for formalizing land and provide a path towards formalizing land ownership. Mottelson (2021, 2020b) finds lower levels of urban tree canopy cover in high-density areas and that urban tree canopy cover in informal settlements decreases over time. Accordingly, the urban tree canopy cover will likely decrease as a result of the urban development in most informal

settlements. This will likely result in increased surface urban heat islands and decreased ground infiltration of rainwater. Accordingly, this development will compromise livelihood, and strategies to increase urban tree canopy cover in informal settlements should be considered a policy priority. Future public-funded infrastructure projects may include tree planting in order to increase urban tree canopy cover. This may increasingly include fruit trees which provide an incentive for local maintenance and nutrition for children. Finally, small scale tree nurseries may receive small subsidies from local administrations for producing tree seedlings. Such policies may improve the micro-climate in informal settlements through increased urban tree canopy cover and thereby improve livelihood. These policy recommendations share some similarities with previous proposals by scholars such as Jenkins (2001), Kironde (2000), Kombe (2005), and Syagga, (2006) which are explained in detail on page 30. However, the policy prescriptions advocated for in academia have generally not been implemented at a large scale by local governments. Furthermore, there seems to be a gap between the policy prescriptions developed in academia and international organizations such as UN-Habitat. Other scholars highlight that elitist interests in maintaining the status quo and thereby perpetuate control of the land are curtailing the political will to address the proliferation of informal settlements through new policy measures (Andersen et al., 2015a). Accordingly, inadequate democratic representation of low-income groups and lack of accountability may constitute key barriers in adopting more effective policy measures. Furthermore, the recommendations outlined in this section relate to general discussions on the applicability of Global North-based urban planning paradigms in the Global South. The standards of administration, governance, and urban planning practice from the North were arguably developed corresponding to societies with more economic resources. The human capital and economic costs of such standards arguably do not correspond to the current conditions in much of the Global South and discussions on appropriate standards and alternative solutions corresponding to the local conditions are thus important for enhancing sustainable development.

REFLECTION ON PRACTICE

The practice-based projects presented in Part III were developed in parallel with the academic research presented in Part II. The hands-on work on construction sites and on formalizing land titles in Maputo provided valuable first-hand knowledge of the administrative practices in the informal settlements. Much of this thesis is relies on such first-hand experience from the context and the research is thus informed by a strong connection with practice. Nevertheless, the practice projects do not represent scientific research as these are based on more traditional architecture practicebased methodologies with less rigorous forms of inquiry and experimentation. However, some of the projects arguably include minor results in creating innovation through alternative approaches to the assignments. The construction

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projects include strategies to optimize the use of resources and lower costs. For example, in Casas Melhoradas locally produced prefabricated elements were developed as an alternative mode of construction in order to minimize the timespan of construction, reduce waste of construction materials, and advance compact city development through demonstration houses. The modular design toolbox developed in the Tana Toilet Blocks project sought to decrease the resources spent on the design and planning of projects while advancing best practice solutions. The experiments with plastic waste sought to advance principles of circular economy in the construction sector in Maputo in order to support waste recycling. Perhaps most notably, the Kyangwali Spatial Planning Project tested alternative low-cost solutions for land surveys and land use management which are linked to the policy proposals concerning innovation in these fields. Accordingly, the project may provide lessons for future application of new methods for land management in informal settlements. Finally, the projects discuss issues relating to urban densification, access to sanitation, as well as innovation in planning and land management which are essential issues presented in the research. Accordingly, these projects have arguably informed the research through tacit knowledge accumulated throughout the practice-based work and provided alternative mediums to the academic work for discussing central issues in this thesis.

FUTURE HORIZONS

This section discusses the frontiers of the studies of urban morphology of informal settlements. In general, the findings presented in this thesis on the significance of ‘informal land supply’ and the impact of urban planning are based on relatively limited data. Accordingly, further studies are needed for advancing the understanding of these issues. Such studies will likely benefit from including l multidisciplinary researchers and analyses based on larger data sets. Several studies suggest that public health outcomes are worse in informal settlements than formal urban areas (Snyder et al., 2014; Sverdlik, 2011). Recent studies have documented a correlation between public health and urban form (Shen & Lung, 2020; Fathi et al., 2020; Hankey & Marshall, 2017). However, limited studies have investigated the relationship between public health and urban form of informal settlements even though several of the indicators of urban slums such as unsafe housing, inadequate access to safe water, and inadequate access to sanitation are linked to spatial factors (Mottelson & Venerandi, 2020). The lack of knowledge on the relation between urban form of informal settlements and public health may compromise public policy in containing the spread of diseases as well as decrease the effect of urban planning efforts to improve livelihood in such urban areas. Accordingly, studies on the relation between urban form of informal settlements and public health conditions may produce interesting and useful results. The link between transportation costs and distribution of densities is widely acknowledged in urban economics (Glaeser, 2020). Kombe (2005) argues that the organic urban

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form of informal settlements does not reflect mainstream economic models. The papers presented in this thesis contribute with some possible explanations to reduce this knowledge gap. Namely, that government restriction of informal land supply may lead to significantly higher population densities in informal settlements in cities with large populations financially excluded from the formal housing market. Furthermore, the studies suggest that the ‘collective investment capacity’ and the time of the establishment of the settlements may account for increased housing supply elasticity. However, the relationship between socio-economic conditions and urban form of informal settlements is poorly understood. Furthermore, as argued previously, the relationship between densities and the time of the establishment has not yet been studied. Accordingly, longitudinal studies on the relationship between socioeconomic conditions and built densification may generate interesting and useful results. Do higher income levels lead to urban densification? Or do people with more resources seek more open space and thus contribute to urban expansion? No studies have investigated these issues in the context of informal settlements in sub-Saharan Africa and the answers may be relevant in addressing the overconsumption of resources linked to contemporary urban expansion in the region. Mottelson (2020a) suggests that urban density and public space ratio of informal settlements are not interdependent and that public space ratio likely is linked to average block sizes. These conclusions need corroboration based on larger scale data sets and more in-depth quantitative analysis. Further studies in this field will likely find links between built densities and street configuration such as higher built densities along internal main streets which score high on centrality measures, as such areas would likely have higher levels of economic activity and thus provide resources for investments in densification. Vice-versa, areas around dead-end streets with low measured centrality will likely show lower levels of built density. Furthermore, Venerandi & Mottelson (2021) find low-density fringe blocks in centrally located informal settlements as much space in these blocks are used for parking. This finding contests the findings of Hillier et al. (2000) who suggested that the built form of fringe blocks consolidates in centrally located informal settlements which are integrated in the formal urban fabric, due to increased economic exchange with the surrounding urban area. Accordingly, further research on this would arguably be significant. Visagie & Turok (2020) examine the conditions for compact city development in informal settlements in sub-Saharan Africa. The extra costs of multi-story construction are arguably an important economic barrier for urban densification in the region (Mottelson & Andersen, 2018). However, increasing costs of land caused by growing urban populations may provide incentives for densification. Specifically, the equilibrium between the cost of land and the extra costs of multi-story construction per area may account for the conditions that will enable large-scale densification based on market conditions. Accordingly, research on the

economic framework for verticalization with an emphasis on land prices and costs of construction will likely generate interesting and useful results in guiding compact city policy in sub-Saharan Africa.

PITFALLS AND POTENTIALS

During my doctoral studies, I encountered three counterproductive positions that I have participated in to some extent. More specifically, these include an excessive focus on semantics rather than material conditions, excessive focus on sophisticated algorithms for computation of urban form metrics, and exaggeration of the potential design application of urban morphology methods. Although I am critical of all three positions it is important to note that I admit to having adopted aspects of these in the papers presented in Part II. More specifically, the paper Understanding Density in Unplanned and Unregulated Settlements of Peri-urban Africa: A Case Study of Maputo, Mozambique (Jenkins & Mottelson, 2020) engages in a lengthy discussion on the appropriate use of terminology. The paper Urban Form of Informal Settlements in East Africa: A Taxonomy of Block Types (Venerandi & Mottelson, 2021) adopts advanced methods to measure and compare urban form while neglecting the fundamental questions such methods should be used to address. However, these experiences have strengthened my views on architecture, spatial planning, and research on cities which are discussed by the end of this final section of the thesis. The first issue raised, namely the excessive focus on semantics, is linked to the emphasis some scholars place on the significance of language in constructing our reality. Such views were notably developed by French post-modernist intellectuals such as Derrida and Foucault and have gained popularity particularly in certain academic and activist milieus since then (Young & Collin, 2004). In the context of this research, the use of the term ‘slum’ has spawned endless discussions on terminology. Some view the term as derogatory to the residents of such areas. Some argue it legitimizes evictions of the residents of such areas (Jenkins, 2013). More recently, the same critique was adopted concerning the term ‘informal settlements’. Perhaps most embarrassingly, an op-ed in the Architectural Review claimed that ‘informality is a fallacy’ without considering the meaning of the term while attributing quasi-racist motives to seminal scholars of informal architecture such as Rodufsky (Agha & Lampert, 2020; Rudofsky, 1987). During the past ten years, I have spent a considerable amount of time in some of the most deficient urban areas in the world and I have never encountered a resident of these areas who was concerned about the derogative connotations of terminology used in academia to describe the obvious problems in their neighborhood. If terminology is used to justify evictions of residents, it is obviously worth discussing. However, it seems that the people in power who authorize evictions find ways of justifying such actions regardless of terminology. This is exemplified by the emerging critique of the use of the term ‘informal’. The term ‘informal settlements’ has a meaning. It refers to the extra-legal conditions relating to the construction and occupancy of the land. Unless you are in

favor of complete deregulation of land acquisition and construction, so anyone can claim land and build on it without regard to regulation, terminology for describing such extra-legal conditions is necessary in order to confront the issues associated with it. It seems that amending the regulation as well as instituting more democratic control and stronger accountability measures of the powerful institutions (public and private) are more important in addressing forced evictions, social exclusion, and inequality than semantics in academia. The continued shifting critique of language may continue indefinitely, first from slums to informal settlements, then from informal settlements to non-formal settlements, and so on. However, any documentation of the effects of such critiques of language remains to be published. Accordingly, I would argue that such efforts should be curbed in favor of application of strategies with a more substantially documented impact. The excessive focus on semantics rather than emphasis on material conditions may be rooted in the neo-liberal global hegemony, whereby the frameworks for ideological discussions exclude viewpoints challenging the economic order of society. Fukuyama (1989) famously claimed ‘the end of history’, with the collapse of the Soviet Union, the end of the cold war, and the consequent global hegemony of free-market liberal democracy. Piketty (2020) argues that the neoliberal hegemony has caused a shift in the critique of ideology. Namely, that capitalism and liberal democracy are so widely accepted as the mode of governance of the social order and as a consequence, postmodernist critique of power structures neglects the fundamental material conditions. Rather than addressing issues of growing inequality through economic measures, opposition to globalization along with the consequent concentration of wealth and consolidation of elite economic power is manifested in an array of movements based on identity politics. On the right, such movements include so-called ‘ethnonationalists’ which are essentially white supremacists who seek privileges based on ethnic or national identity. On the left, single-issue minority rights movements such as LGBTQ support groups and Black lives matter have emerged in order to address structural injustices and in some cases advocate for privileges for these groups. Although policy prescriptions such as affirmative action may be justified given the nature of inequalities based on ethnicity, it is notable that large segments of both the left and right-wing contemporary political movements advocate for privileges based on minority identity rather than universal measures to address inequality. Similarly, although in a different setting, the political spectrum in many African countries transgresses the traditional right-left framework as political parties to some extent are based on ethnic identity rather than social class, as is seen in Kenya (Shilaho, 2018). Varoufakis (2016) suggests that independent nation-states no longer control the fiscal policies in Europe due to the centralization of policy in the European Union and globalization with consequent free flow of capital across borders. Žižek (2011) argues that the hegemony of capitalism is so consolidated that we cannot imagine alternatives to contemporary social order. Chomsky (2016) suggests that international corporations

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constitute the most influential institutions in society. The excessive focus on semantics when dealing with issues of inequality may thus be an outcome of ideological bias as economic policy prescriptions are considered unrealistic within the established system. Furthermore, addressing material inequality related to informal urban development requires an understanding of the institutions, urban policy, and the scholarly literature on the subject. There is no quick fix in this realm and it is much more challenging to disseminate viable solutions as these require expert knowledge to assess. It is simply much easier to develop and publish a critique of language than provide policy responses to the issues associated with informal urban development. Accordingly, the ideological frameworks of public discourse, the complex nature of the discussions, as well as the structural frameworks of contemporary knowledge production and publishing may account for the excessive focus on semantics. In a utopian society where all language is cleared of problematic terminology and the material distribution of resources and the institutional power structures are preserved, the very issues such terminology addresses remain unchanged. Proponents of such postmodernist critiques will likely argue that our frameworks for understanding the problems are embedded in language and changing the language is a necessary first step in changing the power structures and distribution of resources. However, the real-world results of this strategy remain to be documented. If anything, the academic discussion on the inappropriate connotations of the slum terminology during the last 18 years has likely had a limited impact on the real-world urban deficiencies in developing countries, and the term is still used by the UN-Habitat (UN-Habitat, 2020). Accordingly, I would argue that the potential for instigating change in the real world based on changing terminology is exaggerated and discussions on policy for addressing the problems associated with informal urban development are arguably more relevant. The second issue raised in this section, namely the excessive emphasis on technology, is arguably also linked to greater tendencies in society. In my childhood, Gary Kasparov, the highest-ranking chess player at the time lost to the IBM chess computer Deep Blue in a highly publicized match. Since then, computer algorithms have entered all domains of human existence and the tech giants of Silicon Valley have emerged as some of the most valuable companies in the world. Several scholars have noted that the dominating cultures in Silicon Valley perceive problems in society as technical challenges while neglecting conflicts of interest between different social classes (Noble, 2018). Furthermore, the emergence of advanced algorithms, increasing computational power, and access to large data sets have advanced the use of tools such as machine learning based on artificial neural networks, used in areas such as speech recognition, image recognition, and financial fraud recognition (Pasquale, 2015). Such methods are useful applications for developing engineering models for projection of the future or solutions to technical problems. For example, by feeding such algorithms vast amounts of

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data on the movement of a certain bird species, such algorithms may model accurate predictions of the movement of a swarm of such birds. However, it hardly generates any deeper knowledge of the biology or genetics of the bird species. Furthermore, it may be dangerous to succumb control of our knowledge production on which decisionmaking relies on to so-called ‘black box’ computer algorithms we do not adequately understand as possible conflicts of interests are reduced to technical issues. Accordingly, research based on such algorithms may undermine democratic control of society. Deng Xiaoping famously said, “The color of the cat doesn’t matter as long as it catches the mice”, referring to China’s transition from a planned economy to a more market-oriented capitalist economy (Oxford Essential Quotations, 2017; Noble, 2018). Similarly, one might argue that it does not matter how such algorithms reach conclusions as long as they are accurate. However, in this case, it is not only about ‘catching mice’. Policy is also about balancing opposing interests of different groups in society or conflicting considerations such as economic growth opposed to climate change. Reducing such conflicts to a technical matter as is a tendency in Silicon Valley is essentially undemocratic as it reduces an ethical proposition to a technocratic assessment. In addition, Madsbjerg (2017) argues that ‘Big data’ approaches to complex social problems without an adequate understanding of context have shown flawed results. Analogously, Piketty (2014) argues that economists have overly emphasized development of advanced mathematical models in economics, rather than collecting data and analyzing it thoroughly which have compromised the validity of economic theories. Accordingly, the ‘if it ain’t broke don’t fix it’ approach of Silicon Valley may lead to undemocratic decision-making based on flawed analysis. Similarly, applications in quantitative urban morphology risk engaging in technically sophisticated analysis of urban areas without providing new knowledge on how cities develop. I would argue that this is particularly important to emphasize, concerning studies of informal settlements as scholarly work in this field is increasingly done based on publicly available data and no actual field-work. I have even encountered scholars on informal settlements without any ‘hands-on’ experience from the context. The lack of ‘on-ground’ knowledge arguably limits the potential interpretation of the findings and arguably leads to lower quality of research. It seems that some of the quantitative research in urban morphology is driven by an interest in developing advanced algorithms rather than an interest in investigating how cities are shaped. Furthermore, the lack of scholarly work on urban morphology of informal settlements suggests that the basic qualitative work remains to be done before more detailed investigations in this context makes sense. I would label such excessive fascination with mathematics and algorithms ‘tech-fetishism’ and although I support the development of new tools for quantitative analysis of cities, I would stress that the application of such tools should be based on an in-depth understanding of context and in advancing the understanding the processes shaping our cities rather than complex modelling.

The third issue raised in this section, namely exaggeration of the design applications of urban morphology methods, is perhaps the least significant of the three issues. However, just as some scholars are fascinated with advanced algorithms, other scholars seem preoccupied with the succeeding historic layers of the city (see Kropf, 2018; Oliveira, 2018; Strappa, 2018). Perhaps, this position is not surprising given that urban morphology developed from such studies of cartographic maps from historical archives used to trace the physical development of cities alongside social, economic, and technological changes in society over time. However, these scholars arguably exaggerate the potential of such analyses. Space syntax has established a consultancy firm based on provision of morphological analysis in urban design such as evaluation of pedestrian movements in urban planning proposals. However, although such tools may enhance spatial analysis in developing a design brief, it does not provide tangible design solutions. Analogously, the works of scholars such as Kropf (2018), Strappa (2018), and Oliveira (2018) emphasize the design potential in analyzing the historical development of a city. I am somewhat critical of any approach to design that emphasizes a singular aspect of the wide array of factors that contribute to the emergence of high-quality design solutions. The architecture profession is arguably about applying a broader scope to problems and design proposals compared to engineers who are typically specialized in a narrow field such as ventilation, acoustics, or lighting. An excessive focus on one of such aspects will likely not lead to better design proposals. Similarly, a narrow design approach focusing on the historical developments of a context will likely yield mixed results. The layers of historical developments that have shaped the context may constitute an important factor to consider in some cases. In other cases, not so much. In most cases, it is unlikely the most essential driver of the development of an architecture project and it seems counterproductive to teach students to emphasize this single factor in response to the complex challenges that face contemporary society such as energy consumption, adaptability to changing programs, and social inclusion. Lastly, I would like to outline what I believe are more appropriate approaches to architecture, spatial planning, and research on urban morphology. I believe urban morphology research should emphasize development of scientific theories that explain how cities are shaped. These should be based on principles from which you can deduce empirically testable propositions. Urban development policy should in turn be informed by such theories once these have been through rigorous empirical tests and peer review validation. I believe policy based on such empirical research will be advantageous in reaching political goals. Furthermore, research in urban morphology should continue to emphasize the development of tools and methods for analyzing cities. Such tools should advance the development of said theories and knowledge about the mechanisms which structure the development of cities rather than building complex models forecasting the urban development. I believe the latter endeavor can be dangerous as policy might increasingly be

guided by algorithms we do not understand. This may undermine democratic control of society due to a technocratic approach to conflicts of interest and may lead to flawed analyses as seen in previous studies in other fields (Madsbjerg, 2017). Architects and urban planners should increasingly discuss and address the greater challenges facing the world today, such as climate change, inequality, and social segregation. In addressing these issues broad inter-disciplinary holistic analyses are needed rather than narrow single-issue specialists. Such endeavors should arguably include both artistic experiments as well as research-based holistic analyses of the multitude of factors that inform the designer in order to enhance both ethical and aesthetic aspects of design projects. Architects should thus emphasize crossing scales and synthesizing all the different possibly opposing factors into integrated components in the proposals. Design, architecture, and spatial planning are arguably about shaping the physical and material aspects of the human condition in regards to optimization of livelihood and responsible use of the resources. This should include a thorough assessment of the cultural, technical, economic, social, and environmental conditions of the context along a value-based negotiation between these different factors in shaping the design. Accordingly, good design should enhance the quality of life, equitable distribution of resources, and sustainable development for future generations.

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OUT OF CONTROL

On Urban Morphology of Informal Settlements in East Africa Most of the ongoing extensive urbanization in East Africa is informal and occurs beyond the limits of state control and regulatory systems. The urban majority in the region resides in informal settlements characterized by limited urban planning, construction without formal permits, and lack of formal land titles. Issues with substandard housing, overcrowding, insecure tenure as well as inadequate access to water and sanitation are widespread in these areas and compromise the livelihood of tens of millions of urban dwellers. Few studies have investigated the urban form of informal settlements even though spatial factors and urban form indicators such as inadequate access conditions, inefficient use of space, high level of building coverage, and limited public space are linked to some of the urban deficiencies in informal settlements. This PhD thesis presents analyses of the urban form of informal settlements in East Africa based on urban morphology and location theory in order to enhance the knowledge on contemporary urban development in the region and thereby improve the basis for increasing the efficacy of urban planning and policy in addressing the wide-ranging issues linked to the proliferation of informal settlements. The thesis is titled Out of Control as lack of state control is the defining characteristic of informal settlements. The thesis is article-based and includes a number of empirical research papers focusing on various essential topics related to the urban form of informal settlements in East Africa such as informal land markets, urban expansion, and urban planning. Additionally, the thesis includes a number of practice-based design, architecture, and spatial planning projects that were produced in parallel with the research. These projects highlight central issues in relation to informal urban development in East Africa such as urban densification, access to sanitation, as well as innovation in spatial planning and land use management. Mainstream urban economic theory emphasizes the importance of transportation systems in relation to the development of urban form. The findings presented in the thesis add new nuances to these theories by documenting that government attitudes towards informal urban development in cities where the majority is financially excluded from the formal housing market are critical for understanding the urban morphology of informal settlements. More specifically, the thesis argues that government repression of informal urban development in major cities in East Africa decreases informal land supply, leads to higher population densities in the informal settlements, and contributes to the development of more compact urban form. Additionally, the thesis suggests that decreased informal land supply leads to increased competition on the informal land market resulting in higher costs of accommodation as well as consequent fewer resources for investments in household infrastructure which contributes to more compromised livelihood for the urban poor in the region. These findings underscore that Western planning paradigms arguably are not appropriate in the context of much of East Africa as local authorities lack the resources to administer the urban development according to regulation, and much of the population lack the resources to comply with regulation. On this basis, the thesis discusses alternative approaches to urban planning that require fewer resources to administer and support production of affordable legal housing. The thesis presents a number of policy recommendations informed by the findings of the research papers such as new forms of land titling, innovation in land use management, increasing mandate for decision-making to local administrations, road pricing, and implementation of robust street grids in peripheral areas before the urban fabric consolidates. The thesis argues that such policy measures may address some of the issues emblematic to informal urban development in the region and thereby enhance the future sustainable development of major cities in East Africa.

Ph.d.-afhandling: Johan Mottelson - Out of Control

Articles inside

References

Future horizons

Policy recommendations

Born and Raised in the Ghetto By Johan Mottelson

Pitfalls and potentials

Reflection on practice

Informal Horizons By Johan Mottelson, Anton Ryslinge, Anna Wahlén, and Margarida Waco

Tana Toilet Blocks By Johan Mottelson and WSUP Madagascar

Table of contents Abstract

Urban Form of Informal Settlements in East Africa: A Taxonomy of Block Types By Alessandro Venerandi & Johan Mottelson

References

Urban Densification of Informal Settlements in Sub-Saharan Africa: An Analysis of Recent Developments in Maputo, Mozambique By Johan Mottelson

Overview of research papers

Maxaquene Txombene By Johan Mottelson, Remígio Chilaule, Jakob Kisker, and Celso Machaieie

On the Impact of Urban Planning of Informal Settlements in Sub-Saharan Africa By Johan Mottelson