Architecture Thesis_Mei Rahman by Gianmarco Mei

Building resilience through green-blue infrastructures an integrated network for Dhaka

University of Ferrara Architecture Department Academic year 2018-2019 Supervisors Prof. Romeo Farinella Prof. Elena Dorato Co-supervisors Prof. Qazi Azizul Mowla (Bangladesh University of Engineering and Technology, Dhaka) Arch. Md. Iqbal Habib (Bangladesh Environment Movement; VITTI Sthapati Brindo Ltd) Students Gianmarco Mei Ontora Rahman

To Emi and Lotti

table of contents

0.Abstract

1. Urban Resilience 1.1 Urban Resilience definition

5 6

1.2 Organizations 1.2.1 Un Habitat, Urban Resilience Hub 1.2.2 Medellin Collaboration For Urban Resilience 1.2.3 Rockefeller Foundation, 100 Resilient Cities

10 11 12 12

1.3 The focus of resilience: Climate change and Natural disasters

1.4 Hazards and actions 1.4.1 Increase of urban temperature 1.4.2 Flooding

1.5 The case of Dhaka

18 19 21 24

2. water managment & green-blue infrastructures as resilience tools 29 2.1 Examples around the world 30 2.1.1 Europe 31 Copenhagen London Enschede Amsterdam 2.1.2 North America 42 Portland New York 48 2.1.3 Asia Ho Chi Minh City Jakarta Hong Kong Bangalore Sigapore 64 2.2 Is it possible to define a common ground?

3. Analysis 3.1 Current threats to a resilient Dhaka 3.1.1 Environmental issues 3.1.2 Density related issues

71 72 73 78

4. Strategy 4.1 Issues and strategy

3.2. A history of urban water 3.2.1 Development of the city 3.2.2 A changed relation between waterbodies and settlements 3.2.3 Dhakaâ&#x20AC;&#x2122;s water bodies in Patrick Geddes view 3.2.4 Disappearance of water from the urban landscape 3.2.5 Recent shrinkage of water bodies

88 89 94 96 98 102

4.3 Goals and actions 4.3.1 Water management 4.3.2 Green and public space 4.3.3 Mobility

172 173 184 190

3.3 Waterlogging: greatest threat for the city 3.3.1 Embankment: from floods to waterlogging 3.3.2 Causes of waterlogging 3.3.3 Consequences of waterlogging 3.3.4 The drainage system 3.3.5 Organizations and plans 3.3.6 Effects of climate change

104 105 110 112 114 116 118

5. Projects 5.1 Ramchandrapur canal: the banks 5.1.1 Transforming the section 5.1.2 Materials and plant species 5.1.3 Electric waterbuses and stops

197 198 201 203 205

3.4 Dhakaâ&#x20AC;&#x2122;s waterbodies 3.4.1 Fading of canals in Dhaka 3.4.2 Renovated urban water bodies 3.4.3 Suburban area waterbodies 3.4.4 Undeveloped urban canals

120 123 124 128 132

5.2 Ramchandrapur canal: facilities 5.2.1 Integrating water management in public spaces 5.2.2 Mohammadpur sport fields 5.2.3 Public health: exercise and diabetes 5.2.4 Mohammadpur open air amphitheater

210. 211 213 215 216

5.3 Detention park at Tejgaon Old Airport 5.3.1 Tejgaon Old Airport today and its surroundings 5.32 Design principles 5.3.3 Uses and facilities

220 221 224 226

3.5 Public and green space 3.5.1 Typologies and uses of public space 3.5.2 Lack of public green space 3.5.3 Public spaces: habits of the citizens 3.5.4 Good practice in Dhaka: Dhanmondi Lake and Hatirjheel

136 136 147 149 151

6. Conclusions

235

7. Bibliography & Credits

239

8. Acknowledgments

251

9. Attachments

255

157 158

4.2 Strategy: a green-blue network as an integrated solution for a resilient city 166

0 | ABSTRACT

ABSTRACT With 47,400 people per square kilometer, Dhaka is the most densely populated city on earth and at the same time the fourth least liveable. Severe environmental and density-related issues afflict the city, among others floods due to waterlogging, lack of public and green space and traffic congestion. Climate change will further exacerbate this alarming situation by increasing rainfall, temperature and the possibility of extreme weather events. The thesis investigates the possibility to build a resilient city through green-blue infrastructures, by examining the projects made for eleven cities around the world and proposing the implementation of a greenblue network in Dhaka that will act as an integrated solution to the urban issues of the megacity. The project addresses natural disaster risk and the effects of climate change, since the infrastructure, besides being an effective storm water drainage and storage system, is able to reduce the consequences of expected heat waves. In addition the strategy seize this process of urban transformation as an opportunity to provide new and better public green space, to supply a new surface water resource and to reduce traffic by offering protected pedestrian and cycle paths and new waterways for public transport.

ABSTRACT Historically many canals crossed the city but most of them disappeared due to the rapid and uncontrolled urban growth. The infrastructure is therefore built by connecting the still existing ones and by rehabilitating those in poor conditions in order to create a network of canals, with linear parks along their banks, and major urban water detention parks. The project focuses firstly on the rehabilitation of disappearing urban canals, taking Ramchandrapur as pilot project. Secondly, it proposes the conversion of the old airport into a central detention park, an intervention that could be replicated at a smaller scale in other vacant areas. Overall, the project aims to create an urban area able to withstand the present and future chronic stresses and acute shocks, while also increasing the life quality of its inhabitants. Thus, the thesis proposes the implementation of water sensitive urban planning and highlights the importance of natural elements as ecological resources within a dense urban context.

Building Resilience through Green-blue infrastructures

Con 47.400 persone per chilometro quadrato, Dhaka è la città più densamente popolata al mondo e al tempo stesso la quarta meno vivibile. La città è afflitta da gravi problemi ambientali e legati alla densità, tra cui allagamenti dovuti al ristagno idrico, mancanza di spazio pubblico e verde e congestione del traffico. Il cambiamento climatico aggraverà ulteriormente questa situazione allarmante aumentando le precipitazioni, la temperatura e la possibilità di eventi meteorologici estremi. La tesi esplora la possibilità di costruire una città resiliente attraverso infrastrutture verdi-blu, esaminando i progetti realizzati per undici città in tutto il mondo e proponendo la realizzazione di una rete verde-blu a Dhaka che si configura come una soluzione integrata ai problemi della megalopoli. Il progetto affronta il rischio di calamità naturali e gli effetti del cambiamento climatico, poiché l’infrastruttura, oltre ad essere un efficace sistema di drenaggio e stoccaggio delle acque piovane, è in grado di ridurre le conseguenze delle previste ondate di calore. Inoltre, la strategia coglie questo processo di trasformazione urbana come un’opportunità per fornire nuovi e migliori spazi verdi pubblici, per fornire una nuova risorsa idrica superficiale e per ridurre il traffico attraverso percorsi pedonali protetti e piste ciclabili e nuove vie d’acqua per il trasporto pubblico.

Storicamente la città era attraversata da numerosi canali, ma la maggior parte di essi è scomparsa a causa della urbanizzazione rapida e incontrollata. L’infrastruttura è quindi costruita collegando quelli esistenti e riabilitando quelli in condizioni precarie al fine di creare una rete di canali, con parchi lineari lungo le sponde, e parchi urbani di detenzione idrica. Il progetto si concentra in primo luogo sulla riabilitazione dei canali urbani che stanno scomparendo, prendendo Ramchandrapur come progetto pilota. In secondo luogo, propone la conversione del vecchio aeroporto in un grande parco di detenzione; un intervento che potrebbe essere replicato su piccola scala in altre aree libere. Nel complesso, il progetto mira a creare un’area urbana in grado di resistere agli stress cronici e agli shock acuti attuali e futuri, aumentando allo stesso tempo la qualità della vita dei suoi abitanti. In questa ottica la tesi propone l’implementazione di una pianificazione urbana sensibile all’acqua e sottolinea l’importanza degli elementi naturali come risorse ecologiche all’interno di un denso contesto urbano.

Abstract

1 | URBAN 0 |RESILIENCE ABSTRACT

1.1 urban resilience definition

The aim of this chapter is to give a blink of urban resilience, to investigate its fundamental aspects, which constitute a common basis for a more in-depth work, specifically focused on some elements and themes. In particular, the chapter tries to answer three fundamental questions: What is Urban Resilience? Who deals with it? How is it realized? Etymologically, “resilience” comes from Latin “resalio”, iterative of “salio”, which means “to beat” or “ to jump”. The verb was specifically used to describe the action of climbing aboard an upturned ship after capsizing because of the force of the sea. In this meaning, the word connotes a behaviour of forging ahead in the face of adversity, without giving-up. The term “resilience” was originally used in metallurgy: meaning the capacity of a metal to resist deformation from external forces. For a metal, resilience represents the opposite of “brittleness”, commonly named “fragility”, which is the tendency of some materials to break suddenly and abruptly without deformations and yielding occurring previously. In other words, resilient materials, are able to resist and adapt themselves to new external forces that occurs. From the 70’s the term has been implemented in the social science field. In psychology the term describes the individual’s ability to adapt in the face of adverse con-

ditions. Thus it is the ability to cope with a crisis or to return to pre-crisis status quickly. It exists in people who develop psychological and behavioural capabilities that allow them to remain calm during crises/chaos and to move on from the incident without long-term negative consequences. Psychologists started to speak about resilience to describe a positive attitude in particular situations such us pregnancy during adolescence, divorce, death of a family member, failure and setbacks in career. This idea of a “positive adaptation” after a stressful or adverse situation has been extended from single individuals to group of people and communities. Thus it started to be used also in regional and urban planning. The UN Urban Resilience Hub defines urban resilience as the “measurable ability of any urban system, with its inhabitants, to maintain continuity through all shocks and stresses, while positively adapting and transforming towards sustainability”. Therefore, a resilient city is one that assesses and plans to respond to hazards - natural and human-made, sudden and slow-onset. Resilience cities act to protect and enhance people’s lives, secure development gains, foster an investible environment, and drive positive change. Urban Resilience is defined by the “100 Resilient Cities” program of the Rockefeller Foundation as “the capacity of individuals, communities, institutions, businesses, and systems within a city to survive, adapt, and grow no matter what kinds of

Urban resilience

chronic stresses and acute shocks they experience.” This definition embraces a wider range of hazards, in fact it does not only focus on disasters and special traumatic events but it remarks upon the concept that negative pressures on a day to day or cyclical basis can endanger our cities as significantly as outstanding shocks. Academic discussion of urban resilience has focused primarily on three distinct threats; climate change, natural disasters, that are often interrelated, and terrorism. But more resilience cope often also with poverty reduction, environmental sustainability, and social inclusion. Some hazard have always endangered cities and villages such as earthquakes or flooding, Some cultures also developed solutions and settlements pattern capable of facing these threats. Today, cities and city inhabitants are facing additional and amplified challenges as a result of rapid urbanization, a changing climate and political instability, among others. Risks are increasing and so is the urban population. Urban resilience has therefore gained greater prominence over the past decade in international development discourse and has emerged as one of the core principles of sustainable urban development in the global development frameworks and targets. It has been included in the “New Urban Agenda” by the United Nations, in the “Paris Agreement on Climate Change” by the

United Nations Framework Convention on Climate Change and in the Sendai Framework for Disaster Risk Reduction 2015-2030 by the United Nation Office for Disaster Risk Reduction. In addiction Resilience has been included in the 17 Sustainable Development Goals (SDGs) which world leaders adopted In September 2015, as part of the 2030 Agenda for Sustainable Development. In fact the 11th goal is “Make cities inclusive, safe, resilient and sustainable”. The goals, which build on and replace the Millennium Development Goals, officially came into force on 1 January 2016 and are expected to be achieved within the next 15 years. While the SDGs are not legally binding, governments are expected to take ownership, establish national frameworks for their achievement and review of progress. More than half of the world’s human population has lived in cities since 2007, and it is predicted that by 2050, 66% of the world’s population will live in urban areas (UN 2014). So the major resilience challenges of our era, will take places in city. Moreover the high density of people makes them especially vulnerable both to the impacts of acute disasters and the slow, creeping effects of the changing climate. So resilience planning in cities is critically important and can also be seized as an opportunity to increase the urban quality of our built environment.

Building Resilience through Green-blue infrastructures

Urban resilience

1.2 organizations

Different international organizations work on urban resilience, with the goals of supporting the local government and stakeholders in making their urban systems resilient. They work at different levels to produce knowledge and research, to raise global awareness, to create implementation tools, to facilitate access to local funding and to provide policy and diplomatic support, etc. 1.2.1 UN HABITAT, URBAN RESILIENCE HUB The ‘United Nations Human Settlements Program’, the United Nations agency that promotes socially and environmentally sustainable urbanization and guarantees everyone the right to a decent home, has formed an ‘Urban Resilience Hub “Based in Barcelona. It works along three complimentary streams to support to build urban resilience globally: Tools and Guidance The hub works directly with local governments and their partners to provide training, tools and guidance. Local government staff learn new approaches to urban resilience and identify areas where their city may be vulnerable. The fruit of the work with local governments is a set of Actions for Resilience tailored to their urban context. For this purpose “The City Resilience Profiling Tool (CRPT)” has been developed, which is the UN-Habitat’s most extensive tool and follows a people-centered and holistic approach to analyze the entire city

from a resilience perspective. The software, which lies at the basis of the tool, requires filling a standard questionnaire about the city, as an input. The system then processes these data to understand the risks and vulnerabilities of the city and to propose actions. The Hub is responsible for assisting local governments in collecting data and to answer system questions. Data collection alone can take over a year in cities where information is not easily accessible. Also other tools have been created such as the Disaster Resilience Scorecard for Cities, a tool for disaster resilience planning., and the “Quick Risk Esti0mation (QRE)”, a tool to identifying and understanding current and future risks / stress / shocks and exposure threats to both human and physical assets. Knowledge Through the experience gained with cities, the knowledge Hub has significantly grown over the years. The Hub approach gathers best practices, challenges and experiences from local governments and their partners working on resilience issues in order to learn from each other and help to make actions more effective. Advocacy and Partnerships Raising awareness is the first step to increasing engagement in resilience actions. A strong component of their work is telling stories of real cities taking concrete action to protect their infrastructure, functionality and inhabitants. They target local govern-

Urban resilience

ments, the media, donors, civil society and all local actors and groups through campaigns, networks and promotion. Global commitment to urban resilience has grown substantially over the past decade. As a result, a growing number of communities of practice working on the topic have been created. UN-Habitat contributes, leads or hosts a number of the networks to further knowledge, practice and awareness of urban resilience. 1.2.2 Medellin Collaboration for Urban Resilience The Medellin collaboration for urban resilience is a pioneering partnerships platform that brings together the actors involved in the field of urban resilience, chaired by the UN-Habitat. It was launched at the 7th session of the World Urban Forum held in Medellin, Colombia in 2014. It gathers the most prominent actors committed to building resilience globally, including UNISDR, The World Bank Group, Global Facility for Disaster Reduction and Recovery, Inter-American Development Bank, Rockefeller Foundation, 100 Resilient Cities, C40, ICLEI and Cities Alliance Its work is devoted to achieving the main international development agendas. The Medellin Collaboration has designed a platform to help local governments and other municipal professionals understand the usefulness of the wide range of diag-

nostic tools and systems produced to evaluate, measure, monitor and improve the resilience of cities. The Collaboration has created a guide to illustrate how cities are responding to current and future challenges by strategically thinking about design, planning and management aimed at resilience. It is currently working on a collaborative model in six pilot cities: Accra, BogotĂĄ, Jakarta, Maputo, Mexico City and New York City. 1.2.3 Rockefeller Foundation, 100 Resilient Cities In December 2013, The Rockefeller Foundation launched the 100 Resilient Cities initiative, which is dedicated to help cities around the world become more resilient to the physical, social, and economic challenges that are a growing part of the 21st century. Cities in the 100RC network are provided with the resources necessary to develop a road map to resilience along four main pathways: Financial and logistical guidance for establishing an innovative new position in city government, a Chief Resilience Officer, who will lead the cityâ&#x20AC;&#x2122;s resilience efforts Expert support for development of a robust Resilience Strategy Access to solutions, service providers, and partners from the private, public and NGO

Building Resilience through Green-blue infrastructures

Map of the 100 resilient cities (www.arup.com/perspectives/city-resilience-index)

sectors who can help them develop and implement their Resilience Strategies Membership of a global network of member cities who can learn from and help each other. Through these actions, 100RC aims not only to help individual cities become more resilient, but will facilitate the building of a global practice of resilience among governments, NGOs, the private sector, and individual citizens. The program noticed a difficulty to identify

a way of considering resilience from a quantitative perspective or to develop a general metrics to measure resilience. While it was possible to determine whether a city was resilient or not, it was difficult to determine to what extent a city was resilient or not. It was quite hard to compare the level of resilience of different cities.. To overcome this challenge, the professional services firm Arup has helped the Rockefeller Foundation develop the City Resilience Index based on extensive stakeholder consultation across a range of cities globally. The index is intendUrban resilience

ed to serve as a planning and decision-making tool to help guide urban investments toward results that facilitate sustainable urban growth and the well-being of citizens. The hope is that city officials will utilize the tool to identify areas of improvement, systemic weaknesses and opportunities for mitigating risk. Itâ&#x20AC;&#x2122;s generalizable format also allows cities to learn from each other. The index is a holistic articulation of urban resilience premised on the finding that there are 12 universal factors or drivers that contribute to city resilience. What varies is their relative importance. The factors are organized into the four core dimensions of the urban resilience framework: Leadership and strategy Effective leadership and management Empowered stakeholders Integrated development planning Health and well-being Minimal human vulnerability Diverse livelihoods and employment Effective safeguards to human health and life Economy and society Sustainable economy Comprehensive security and rule of law Collective identity and community support

Map of the 100 resilient cities (www.arup.com/perspectives/city-resilience-index)

Building Resilience through Green-blue infrastructures

Reliable mobility and communications An independent report from the Urban Institute found that 100RC is making important progress in helping cities institutionalize resilience and implement solutions to shocks and stresses, with a model that has unique breadth and depth of engagement, and lessons from its work spreading beyond the existing network of cities. Most comparable programs have focused on projects or services, while 100RCâ&#x20AC;&#x2122;s theory of change foregrounds the transformation of institutions and systems in cities in addition to project implementation. As more and more cities begin to implement strategies and institutionalize resilience, the 100RC has announced that their organization must also evolve to continue the work of this global network. The Rockefeller Foundation has made the decision to transition the work of 100 Resilient Cities into at least three separate pathways. A detailed organizational plan has not been released yet, so it is sure that the structure of 100RC will change, but is not known how. Anyway the Rockefeller Foundation assured that it will continue to actively work in the resilience field.

Infrastructure and environment Reduced exposure and fragility Effective provision of critical services

Urban resilience

1.3 the focus of resilience: climate change and natural disasters

As stated above climate change and natural disasters are two of the main threats with whom urban resilience is coping. Both in the academic area and in the urban and regional planning, climate change and natural disasters are the two main focus of resilience. In other words, when speaking about urban resilience, we are inevitably referring to the effects of climate change and to natural disasters. The vagueness of the term “resilience” has enabled innovative multi-disciplinary collaboration and let the concept of resilience embrace new aspects, social end economical. Among others. This has led to positive changes and effective strategies but this different fields keep to be in the background when dealing with urban resilience, while climate change and natural disasters keep to be in the foreground. Climate change and natural disaster are two interrelated phenomenons. Although natural disasters have always happened, so they obviously exist independently from climate change, their more frequent occurrence in recent years is caused by the changing climate, as scientists have demonstrated. Climate change is therefore boosting the occurrence of natural disasters. With increasing global surface temperatures the possibility of more droughts and increased intensity of storms is likely to occur. As more water vapor is evaporated into the atmosphere it becomes fuel for more powerful storms to develop. More heat in the atmosphere and warmer ocean surface temperatures can

lead to increased wind speeds in tropical storms. Rising sea levels expose higher locations not usually subjected to the power of the sea and to the erosive forces of waves and currents. Referring to urban resilience definition of the 100 Resilient Cities program by the Rockefeller Foundation, cities can experience “chronic stresses” and “acute shocks”. Under this definition, natural disasters are obviously acute shocks, while climate change endangers the built environment on both levels. Climate change produces both acute shocks, being responsible for some natural disasters, and chronic stresses, mainly in the form of generally more intense rainfall and increased average temperatures. For example the rise of the average temperature in the city of a couple of Celsius degrees (due to climate change), is not an immediate catastrophic events with disgraceful consequences, but it is a pressures applied on a daily basis to an urban system which can lead to detrimental effects.

Urban resilience

1.4 hazards and actions

This paragraph investigates the main threats for cities with whom resilience is coping and how it is doing it. The section examines the major issues from which city are and will be afflicted that may be represented under two main categories: problems related to urban temperature and floodings. Furthermore general guidelines to tackle these problems will be presented to have a glimpse on how urban area can withstand and adapt to the average increase of temperature and floodings.

1.4.1 INCREASE OF URBAN TEMPERATURE The increase of urban temperatures is driven both by large-scale climatic changes and ongoing urbanization. In fact the already mentioned rise of temperature due to climate change is exacerbate by Urban Heat Island in densely built up area. Urban Heat Island (UHI) refers to the presence of an inner-city microclimate in which temperatures are comparatively higher than in the rural surroundings. Recent studies have shown that summer daytime temperatures can reach up to 10 Â°C hotter in a city center than in rural areas and between 5â&#x20AC;&#x201C;6 Â°C warmer at night. The materials commonly found in urban areas (concrete and asphalt) absorb and store heat energy much more effectively than the surrounding natural environment. The black

coloring of asphalt surfaces (roads, parking lots and highways) is able to absorb significantly more electromagnetic radiation, further encouraging the rapid and effective capture and storage of heat throughout the day. Geometrics come into play as well, as tall buildings provide large surfaces that both absorb and reflect sunlight and its heat energy onto other absorbent surfaces. These tall buildings also block the wind, which limits convective cooling. The sheer size of the buildings also blocks surface heat from naturally radiating back into the cool sky at night. These factors, combined with the heat generated from vehicles, air conditioners and industry ensure that cities create, absorb and hold heat very effectively. This change of temperature performs a chronic stress on cities but can also generate acute shocks in the form of heat waves Heat waves are periods of weather where the temperature is unusually high compared to the average temperatures of that given region at that time of the year. Serious drought problems are usually associated with them. They produce losses in the agricultural harvest with consequent increase in food prices, greater demand for electricity, forest fires, pollution and reduction of boo-diversity. These two phenomena are today already serious dangers for the population. For example it is estimated that the heat wave of August 2003 has caused more than 46,000

Urban resilience

deaths throughout Europe. But the problem will tend to worsen further: Statistically the urban population is most affected by the consequences of heat waves and droughts, due to the increasing population density and socio-economic inequalities. The weakest part of the population is the one most vulnerable to heat waves and droughts. Underprivileged population such as the elderly, the homeless or those living in slums, are those who do not receive assistance from other people, do not have access to air-conditioned environments and do not have decent accommodation. Making urban spaces green is one of the most frequently mentioned strategies for dealing with the effects of heat. The idea is to increase the amount of natural coverage within the city. This cover can consist of grasses, bushes, trees, vines, water, rock gardens or any natural material. Covering as much surface as possible with green reduces the total amount of thermally absorbent artificial material, furthermore the shading effect reduces the amount of light and heat that reaches the concrete and the asphalt that cannot be replaced by green (++ et al. 2000). Of course trees are among the most effective greening tools in urban environments thanks to their coverage / bulk ratio. They also absorb solar energy for photosynthesis (improving air quality and mitigating the phenomenon of urban heat

island), thus reducing the amount of energy trapped and retained within artificial surfaces and creating the necessary shade for citizens. The shadow itself does not lower the air temperature, but significantly reduces the perceived temperature and improves citizen comfort. (Tidball et al. 2007). Another popular method to reduce the heat island phenomenon is simply to increase the albedo (light reflectivity) of urban surfaces. This is done using paints or reflective materials or white and light-colored options, where the reflections could be distracting or dangerous (Environmental Protection Agency 2011). Green roofs can contribute to resilience to both heat waves and floods. However, their reduced surface and their punctual character make them scarcely effective; they also have high management costs. The removal of surplus flooring is a more effective and also economically more convenient approach. Reservoirs of drinking water should be expanded and new water basins and water towers should be built in areas where critical deficiencies are found. Cities near the coast can also consider desalination plants, although they are more expensive. Infrastructure quality plays an important role in urban resilience. In fact in many cities aqueducts, that are often old and poorly maintained are subject to large losses (up to 50%) and possible contamination. In these cases, replacements and repairs are clearly

Building Resilience through Green-blue infrastructures

necessary.

cal pollution and, more frequently, viral and bacterial contaminants.

1.4.2 FLOODING Floodings are part of the natural events that take place in our environment. Particularly famous from ancient history are the floods caused by the river Nile. In fact the river used to overflow its banks annually, making the surrounding land fertile through its silt deposits. This floods had a positive impact on the area and a fundamental role in the founding of Egyptian civilization. Nowadays floodings are a major cause of death, disease and economic losses throughout the world. Their occurrence has recently been boosted by the increase in rainfall intensity, sea level rise and the melting of glaciers, all consequences of climate change. Cities are particularly vulnerable to flooding because most of their soil is impermeable (due to buildings and roads), so they are unable to absorb the large amounts of water that flow into them and direct it into sewers, often overcoming their capacity. Worldwide, floods kill thousands of people every year and are responsible for billions of dollars in damage and economic loss. Floods, just like heat waves and drought, can also devastate agricultural areas, rapidly destroying large quantities of crops. In cities with poor or absent drainage infrastructures, floods can also lead to contamination of drinking water sources (aquifers, wells, inland waterways) with salt water, chemi-

The increase of urban green space is effective in improving flood resilience. In fact, by replacing as many non-porous surfaces with green areas it is possible to increase the natural absorption of excess water by the soil and plants. One of the best strategies is to create areas where excess water can be conveyed. In this perspective it is possible to create canals to collect excess water that lead to specially created detention basins. These spaces can be green areas available for the community when they are dry (not affected by flooding) or parking areas with porous flooring (which must be previously evacuated in the event of flooding). Other possibilities are the use of innovative porous materials for paving roads and parking areas that allow water to be absorbed by the ground. The banks are another essential element for flood-water control. When implementing these systems, however, it is essential to pay particular attention not to completely isolate the waterways from the city. It is necessary to ensure that citizens can still access the areas near the water courses and that they can enjoy them (also on a visual level) so that the relations between the city and the water bodies are not lost. Structural resilience is fundamental to re-

Urban resilience

duce the hazard of floods. In high-risk areas, facilities should be built according to flood-resistant standards, living or working areas should be elevated well above the

flood levels of the worst-case scenario and infrastructure such as power grids should be placed at appropriate heights or made floating. Consideration should also be given

Flooded street in Dhaka (www.xinhuanet.com)

Building Resilience through Green-blue infrastructures

to the possibility of relocating utility buildings such as schools, hospitals, emergency services, etc. on highlands.

Flooded street in Dhaka (www.climatevisuals.org)

Urban resilience

1.5 THE CASE OF DHAKA

Dhaka, being the capital of Bangladesh, is the center of a developing country that is making leaps and bounds in economic growth and development. The country has maintained an impressive track record on extreme poverty reduction and shared prosperity since the country’s independence in 1971. In the past decade alone, the economy has grown at nearly 6 percent per year, and human development went hand-in-hand with economic growth. Poverty dropped by nearly a third, coupled with increased life expectancy, literacy, and per capita food intake. More than 15 million Bangladeshis have moved out of poverty since 1992. The country has the highest population density in Asia and this strong economic growth prospects have fueled a massive population shift to Bangladesh’s urban areas, which now register a density of around 1,900 people per sq. km, – among the highest in the world. The sustained growth and rapid urbanization is exerting great pressure on urban development and the delivery of basic public services, and substantial efforts are needed to improve quality of life for all. Bangladesh’s cities are characterized by an ever-widening infrastructure deficit and more and more people are bound to living in sub-standard conditions. Sound planning and development are lacking, and new projects are encroaching on already limited open space. Processes for quality control of construction and adherence to building code provisions and other standards are insufficient. Further-

more, the government lacks the capacity to tackle the threat of man-made and natural disasters within this context, putting millions at risk. Bangladesh is one of the most disaster prone country in the world , and is highly exposed to a variety of hazards such as floods, cyclones and earthquakes. The Government of Bangladesh (GoB) has instituted disaster risk reduction policies and invested in infrastructure along coastal areas to mitigate the risk from floods and cyclones. These actions demonstrated to be effective by saving life, reducing economic losses and protecting development gain. Despite this tangible success in the coastal region, the vulnerability of Bangladesh’s urban areas is not as well understood – or addressed – in the country’s policy framework. Dhaka area is particularly at risk as described in the 2008/2009 State of World Cities of the UN Habitat. The capital is one of the largest mega-cities in the world but also one of the least planned urban centers. It is located between 4 rivers prone to flooding and is squeezed between the Himalayan mountain range and a basin of water that generates violent cyclones, occasionally tsunamis and submerges new land every year, eliminating particular fertile land in deltas, contaminating drinking water and forcing entire villages to emigrate. In this context approximately 28 percent of the population is already classified as poor,

Urban resilience

and an estimated 300,000 to 400,000 poor migrants arrive in the city on a yearly basis. In addiction land use planning regulation, and public service delivery in the urban areas of Bangladesh has failed to keep up with the pace of growth. Thus physical and social vulnerabilities keep increasing and any hazards such as floods, building collapses, or earthquakes present a formidable threat to life and prosperity. This already disastrous basic scenario is further aggravated by considering the consequences of climate change. Climate change has produced a progressive increase in temperatures on the planet, so glaciers and snow on the Himalayas will increasingly tend to melt. Part of the large amount of water that will derive, will follow the orography of the region and tend to go towards the Indian Ocean, crossing all those area that separate the mountain range from the sea. The region of Dhaka, given its geographical location, will be affected by this phenomenon, that will increase the flooding risk. In addition the changing climate will increase in the intensity of precipitating phenomena, so the city will need to manage a bigger amount of runoff water in shorter periods Furthermore Dhaka is located between 2 and 13 meters above sea level, so even a slight increase in sea level could have terrible consequences on the city.

flooding, climate change will also add the hazards of higher temperatures and heat waves, assisted by the increasing emissions due to the rise in the number of vehicles, industrial activities and the use of air conditioning systems. In addition, its extremely high urban density makes it particularly susceptible to environmental disasters. Dhaka already has a population of almost 19 million and continues to be one of the fastest growing cities in Southeast Asia. This means that the consequences of climate change will affect a very large number of people, in particular from the poorest sections of the population, who often live in informal settlements and/or areas prone to flooding. Some flood protection actions have already been implemented in the Greater Dhaka district. The government, following frequent floods in the 1980s, has already completed the construction of an embankment around the city to protect it by the overflow of rivers. This system has been completed by pump-station, to let the storm water flow out of the city to the rivers. Although this embankment has addressed the hazard of flooding, it has created a waterlogging problem. So today Dhaka keeps to be inundated and any significant step has been made towards resilience. This situation will be further investigated in the following chapters.

Joynub Nabila Obayed, Water Logging (www.world-street.photography)

In addition to the boosting the danger of

Building Resilience through Green-blue infrastructures

Urban resilience

2 | water managment and green-blue infrastructures 0 | ABSTRACT as resilience tools

2.1 examples around the world

2.1.1 EUROPE

The Copenhagen Cloudburst Management Plan Country: Denmark City: Copenhagen Year: 2012 Copenhagen, aerial view (www.flickr.com/photos)

The Copenhagen Cloudburst Managment Plan, which is an offshoot of the Copenhagen Climate Adaptation Plan, addresses the challenges caused by cloudbursts and floodwater. The mitigation of the risk of rain flooding in Copenhagen will contribute to the blue and green infrastructure if adaptive measures are applied or by draining excess water at ground level. Initially, the Climate Adaptation Plan, which sets the framework for the implementation of Climate adaptive measures in the City Administration area, recommended that rainwater caused by extreme rainfall should be evacuated from the parks to flood lands. The idea was to store rainwater in these buffer areas until the drainage system recove-

red its capacity. The extreme rain event of 2nd July 2011 and subsequent calculations have now demonstrated that this method consists in preventing flooding only in large areas of the city. In fact, the evaluations show that the method of storage would cover a minority of the territory for rainwater drainage. New studies show that storage should be completed by measures in which water is carried into the sea through roads, canals, urban waterways and underground tunnels. Most of the precipitations caused by heavy downpours must be therefore discharged into the sea through new flow routes, while a smaller part must be conveyed towards fresh water.

Water managment and green-blue networks as resilient tools

The city of Copenhagen aims to increase the future of the green-blue infrastructure. Drainage and intensive waste treatment are consequently an important element in the Copenhagen physical planning process. Therefore, adaptive pluvial flood measures must be incorporated into local master plans and urban development projects. A green-blue infrastructure in a city expresses the correlation between water in streams, canals, green spaces, parks and urban areas. This holistic approach of the plan reintroduces water as a resource in urban life, whereas the traditional approach aims to maximize the socio-economic value by proposing cycle paths that serve as temporary canals and green avenues with waterways.

The initiatives could include the re-opening of the streams, the construction of new canals or the creation of lakes and more green spaces, and the use of high-cordoned roads to carry the flooded water. However, the quantities of water to be handled are so large that it would be impossible to transport all the floodwaters to the most densely populated area of central Copenhagen. In these areas, water can be brought to the port through large pipes. They will be lying down to the level of not disturbing anything located directly above. It is necessary to plan and invest in adaptive actions, protecting the city from flooding and relieving pressure on surface currents on all other days with precipitation.

Arena and sports area (www.toposmagazine.com/enghaveparken-copenhagen-denmark)

The Copenhagen Cloudburst Formula (www.asla.org/2016awards)

Building Resilience through Green-blue infrastructures

Starting from a socio-economic perspective, it is worth opting for solutions that are able to manage the ordinary rains that will become increasingly frequent with climate change. The city has carried out a complete evaluation of the costs of the various measures, the cost of the damages and the consequent financial impact. It has been shown that continuing to focus on traditional sewage systems would have resulted in a negative collective gain: despite the capital investments, the financial damage due to flooding would remain high and would

not justify the high investments in implementing the measures. On the other hand, the combined solution would result in net savings. Ideally, adaptive pluvial flooding measures in Copenhagen will protect Copenhagen by combining measures that will make the city greener and bluer and will drain rainwater at a ground level. The plan provides adaptive measures in flood risk and implements the synergies with other projects such as road renewal, urban development, etc.

Water managment and green blue networks as resilient tools

All London Green Grid Country: United Kingdom City: London Year: 2012 London wetland centre (www.independent.co.uk/life-style)

The All London Green Grid aims to fill the void created by the lack of a merged vision of open spaces and the city’s green existence, ensuring that the contribution they make to quality of life, the environment and the economic system are maximized. London is already exposed to climate impacts such as floods, droughts and heatwaves. Further climate change is expected to bring hotter and drier summers, warmer and wetter winters, and an increased frequency and intensity of extreme weather events, such as heatwaves and very heavy rainstorms. The predicted rise of sea levels, wetter winters and increased incidences of heavy rainstorms will increase the likelihood of flooding from tidal, fluvial, surface water and sewer sources.

Currently, 83.200 properties in London are at risk of flooding from rivers and 680,000 properties are at risk of flooding from heavy rainfall. Changes to permeability of the urban landscape will also increase the likelihood of flash flooding, whilst London’s growth will mean that more people and properties may be at risk. While the existing flood defences, drainage system and green space network already contribute to managing flooding, the increasing risk from climate change effects will require creative solutions to be incorporated into the design of existing and new development. An expanded and reshaped network of green-blue infrastructure could significantly absorb and temporarily retain rainwater, reducing both strategic and local

Building Resilience through Green-blue infrastructures

flood risk. There are significant opportunities to use green-blue infrastructure to complement the current drainage systems, so avoiding, or at least delaying the need to introduce further grey infrastructure.

extension. It is vital to consider the green-blue infrastructure as an incorporated part of the city’s metabolism, together with its roads, railways or drainage system.

The best way to evaluate and manage green-blue infrastructures is to see it as a network extended through the whole city. Some places are already well served and here the task is to be sure that it remains high quality and is managed effectively. Other places suffer from deficiencies in green spaces, and here there’s the need to extend the network. This highlights the importance of adopting an integrated approach to management, improvement and

The green-blue network will have an increasingly important role during the challenges of growth and climate change. Green-blue infrastructures can help absorb water, cool the urban environment and clean the air; it can be used to promote sport and leisure and to provide space for London’s fauna and flora. As a network, it can provide links and connections between places, encourage walking and cycling, highlight the landscape and heritage and support the local economy.

The All London Green Grid (http://www.landscapearchitecture.org.uk/all-london-green-grid/)

Water managment and green blue networks as resilient tools

The All London Green Grid structure is built around four key elements: 1) The existing London river and other key landscape corridors, 2) Established open spaces and identified opportunities to create new parks, 3) The existing green links and corridors 4) The designated and protected landscapes that are generally located at the boundary of London . The plan promotes the transition from gray to green-blue infrastructure to ensure environmental, social and economic benefits. It is a progression from perceiving London as a city dotted with parks, green spaces and surrounded by the countryside, to appreciate this network as part of the cityâ&#x20AC;&#x2122;s fundamental infrastructure. This connected network will improve the function, use and performance of the current blue-green infrastructure. The Plan encourages the integration of the green-blue infrastructure with the Blue Ribbon, a space policy that covers the waterways and water spaces of London and the land alongside them. It includes the Thames, the network of canals, the other tributaries, rivers and streams within the open spaces of London and London, such as basins, basins and lakes.

that it can be used in many different ways, including pedestrians, for water management, for cooling gray urban spaces and as an ecological corridor. The objective of this approach is to plan and manage networks of natural and cultural landscapes and open spaces in a strategic way to preserve the functions of ecosystems and provide a series of benefits for people. In order for this scale of development to be sustainable, to respond to climate change and improve the health and quality of life of Londoners, a radical change in environmental quality and performance is needed. One of the goals of the ALGG is that London should excel among global cities, achieving the highest environmental standards and quality of life and leading the world in its approach to tackling the urban challenges of the 21st century, in particular that of climate change.

As in the case of Londonâ&#x20AC;&#x2122;s streets, the ALGG offers an arrangement of attractive green spaces and paths that connect London. Being connected, the value and function of the ALGG are significantly improved so

Building Resilience through Green-blue infrastructures

The River Roombeek Country: The Netherlands City: Enschede Year: 2008 The Roombeek (www.santenco.nl/nl/nieuws)

The rivers played an important role in the foundation of the city of Enschede. The first inhabitants settled there because of the great availability of water. They used water as drinking water to wash, irrigate the fields and even as a defense measure of the city, in fact up until the nineteenth century the city even had a moat. The Roombeek was one of the main bodies of water in Enschede. For centuries the Roombeek was the main hydrological foundation for the textile industry and was also used for the disposal of gray water. At the beginning of the nineteenth century the textile industry was flourishing in Enschede and more and more water was needed. Instead of running water, industries began to use groundwater because it is wi-

dely available. Excessive exploitation of groundwater resulted in the exhaustion of the upper flow rates while the textile industry poured the intoxicated water into the river, polluting it. Today it is possible to find in the soil the paints for fabrics during excavations. Enschede has continued to grow and more and more domestic wastewater has been discharged into the streams. In times of drought, when there was almost no water to flow into the streams, the city was invaded by stench. At some point the decision to cover the waterways was made and sewers were built for water drainage. Meanwhile, the textile industry has continued to extract more and more groundwater. This has led some parts of the river to

Water managment and green blue networks as resilient tools

become completely dry. The space was useful for building roads and houses and more and more parts of the body of water have been buried. Gradually the Roombeek disappeared completely from the city. Most industries have stopped extracting water from the ground. The result is that the aquifer is almost as high as when it was in a favorable position for the bleach fields. In recent years, complaints relating to high groundwater levels have naturally increased. The flooding caused by the high level of groundwater has been solved by the owners of the houses who have installed a small pump to remove water under the foundations. The collected water is often discharged into the sewers, in the absence of an alternative and this causes an effort to drain the sewage system, overflow problems and inefficient use of sewage water. Enschede is currently working on a disjoint sewer system, ground and underground water and infiltration measures. River flows have always played an important role in flood prevention. The flows attract underground water from the immediate surroundings and the quantity depends on the type of soil. Groundwater in many places in Enschede is polluted by the former textile industry. To clean the groundwater it is pumped and treated. This water is also discharged and, when possible, infiltrated. Problems with excessive groundwater require a good and sustainable solution.

Various experts and organizations have collaborated on the future of water in Enschede. These include the city of Enschede, the water panels of Regge and Dinkel, the water supply consortium Vitens and the province of Overijssel. In 2002 the parties created Enschede Water Vision. The goal is to restore the blue network of the city, of which Roombeek is also part In the process of rebuilding the Roombeek district, the ambition to restore the old Roombeek soon became visible. Both residents and city councilors wanted to bring this piece of Enschede history back to the forefront. This action will make water management more sustainable, improve quality of life and increase environmental quality. Depending on the adjoining situation and local options, Roombeek flows into a bed of the natural river, in a system of urban canals above ground, through ponds and sometimes even through pipes. Where the Roombeek flows underground, a strip of blue tiles marks its path above ground.

Building Resilience through Green-blue infrastructures

IJburg islands Country: The Netherlands City: Amsterdam Year: 1997 IJburg urban district (www.urbangreenbluegrids.com/projects)

IJburg is an urban development neighborhood located in the eastern part of Amsterdam. Once the project is completed, it will include around 18,000 homes. IJburg is built in the IJsselmeer, a very large artificial lake that borders Amsterdam in the north east part. This means that the existing functions and natural requirements of the water system had immediately to be taken into consideration for the realization of the district. Both in the first phase of IJburg and in the second phase, in an improved form, the aim has been to enhance the natural elements. An extraordinarily high density of 71 houses per hectare is expected on average (in the second phase this number rises to 90

houses per hectare) together with the conservation of water quality in the IJsselmeer and the maintainance of the high aesthetic value. Water can be experienced almost anywhere on the islands: along the limits of the islands, but also close to almost every house in the center of the islands thanks to the waterways. One of the islands, Haveneiland, has a more rocky and urban character and most of the multilevel constructions. On Steigereiland the focus is on living on water and around water: experiments have also been made with architecture and private projects. The reed islands mainly have houses on the ground floor. Based on the introduction of stricter national and European

Water managment and green blue networks as resilient tools

The water system for the first phase of IJburg is different from the water systems in other IJsselmeer river reclamation projects: it was decided that IJburg’s level would be raised rather than drained. This peculiar approach to land reclamation was chosen because of the “standstill” principle, according to which the creation of new territorial areas may not affect the quality of the surrounding waters. Therefore, rainfall on the IJburg islands is retained for as long as possible and treated.

IJburg urban plan (www.urbangreenbluegrids.com/projects)

laws, the improvement of natural assets in the immediate proximity of the new islands will require attention in the second phase. The IJsselmeer is a Nature 2000 area, a network of sites of Community interest and special protection areas created by the European Union for the protection and conservation of habitats and animal and plant species. The characteristics of its surface, protected and rich in nutrients and the abundance of crustaceans and aquatic plants make the area attractive for water birds. Although IJburg itself is located just outside the protected area, the construction of the new islands must be conducted in such a way as to have no significant impact on the protected area.

Most waterproof surfaces are not connected to surface water. The outflow is allowed by infiltration into the ground through special drainage channels. Once infiltrated, the

water passes through banks of reeds that further purify the water and through the surface water of the island. The clean water can then be discharged into the surface waters of the IJsselmeer. Traditional polders require constant and continuous monitoring of the pumping of water from the discharged area. The quality of the discharged water cannot be controlled, or only to a limited extent, particularly during peak drainage periods. On the other hand, the system used for IJburg offers the possibility of treating the water before it is discharged.

Furthermore, IJburg is located in the main ecological structure between the Vecht river region and the Waterland areas. The creation of islands has proved to be a better solution than land drainage, both for environmental reasons and in terms of quality of life. The plans pay much attention to the natural coasts and the regular flow of water. The realization of IJburg does not necessarily mean that natural assets will be limited: the new district will offer more shores and shelters, and the water will become clearer as the mud will settle on the bottom. To counterbalance the construction of IJburg, Amsterdam is collaborating with a large number of other parties to create three new natural areas: Hoekelingsdam, Diemer Vijfhoek and Zuidelijke IJmeerkust.

Building Resilience through Green-blue infrastructures

IJburg residential area (www.urbangreenbluegrids.com/projects)

Water managment and green blue networks as resilient tools

2.1.2 NORTH AMERICA

The “rain gardens” and the green streets are therefore born, which are permeable areas in private appliances and public spaces, in which rainwater can flow into the soil and feed into the ground.

Plan for 2030 Country: USA City: Portland (Oregon) Year: 2012 Portland, aerial view (www.visittheusa.com/destination/portland)

Oregon is considered the home of the natural beauty of the USA. Between coasts, mountains, forests and rivers, it offers various opportunities for lovers of natural adventures.

fluence of two rivers; the city is located in an area rich in waterways which, with the expansion of the urban area, underwent waterproofing processes with consequent damage.

The most populous city, Portland, perfectly reproduces the image of the State and does so by combining ecology, urbanization and man, in a fabric that includes about six hundred thousand inhabitants. Thus, Portland has become the “green city” par excellence, recognized and appreciated throughout the world.

The city of Portland has undergone significant urban development since the 1990s, with important phenomena of waterproofing and compaction of soils that have led the public administration, with the active involvement of citizens, to interventions of re-permeation of the soil and shared management of rain water, to cope with the inadequacy of rainwater collection networks, pollution and flooding of rivers.

Portland is located in the northern part of Oregon, in the most populated region of the state, the Willamette Valley, at the con42

Building Resilience through Green-blue infrastructures

The Portland administration, next to the system of “green-blue corridors”, which connect in a continuous network of parks, green spaces, water bodies and urban polarities, has defined a 2030 plan for sustainable mobility, programmatically integrated with water management and urban environment improvement policies. The green-blue corridors are a privileged facility for soft mobility and are equipped for public transport and access to functions of collective interest. A structured network of Greenways makes it possible to connect neighborhoods to each other by walking or cycling. The system supports the entire urban organism through a new type of network infrastructure, destined to a plurality of environmental functions and to produce positive effects on the quality of the urban environment and on mobility behaviors. Construction, transport, energy and waste management are just some of the sectors in which the town has created “green” models. Some useful data to better understand the way of daily life in the city: around 25% of the inhabitants move using public transport, carpooling or bicycles (through

its more than 400 km of cycle paths); about 33% of the energy used is produced from renewable sources, and many buildings have LEED certification for environmental sustainability. Recycling affects 60% of the waste produced. That the green concept has now become part of the daily life of the inhabitants of Portland, it can also be understood walking through the central areas. One of the prime actions of the climate action plan, in fact, foresees the expansion of the urban forest so as to cover a third of Portland, and at least 50% of the length of the river in the city, putting the new green next to the water. The actions undertaken have seen the growth of public and private programs to encourage planting, conservation and maintenance of trees and shrubs, invasive species control and the removal of regulatory obstacles. All this combined with the acquisition, restoration and protection of natural and forest resources to reduce the “urban heat island” effect, improving the quality of air and water. The concept, ultimately, is to recognize trees, shrubs, vegetation and natural landscapes as a public heritage of the city and the county. Even the buildings have been touched by the “green” way of thinking, with the evaluation of “green” alternatives to public infrastructure projects.

Portland has succeeded in an exemplary fashion in combining goals in ter-

Water managment and green blue networks as resilient tools

ms of ecology, water management, art and participation, which resulted in the peculiar urban design: Tanner Springs Park. On a former industrial estate, a new urban district has arisen whose value increased when this water-rich city park was realised. The park’s design draws inspiration from the area’s original natural state, before it became an industrial site and marshalling yard. Its wetland character was restored in an urban setting by including

water features, reintroducing groundwater and planting suitable vegetation. Rainwater that runs off from impervious surfaces and the adjacent streets is buffered in the pond. The pond is situated at the lowest point of the slope, approximately 1.80 metres below street level. The pond is bordered by a 60-metre-long artwork, the Art Wall, made from old rails found in the area. While the city park was being designed, workshops were organised to involve the residents, local businesses and users of the district.

The big U Country: USA City: New York Year: 2012 The Big U (www.dezeen.com/2018/07/20)

New York is the third city in the world with the best green area ratio per inhabitant of 23.11 square meters. The green soul of the city, however, has ancient roots, since the first project for a city park shaped by the human hand was developed and realized right here, in the mid-nineteenth century: it is Central Park, the biggest “green lung“ of NYC, with a total area of 340 hectares. The urban greenery is therefore a predominant aspect of the town’s architecture. Green spaces can not only be effective in reducing air pollution and promoting psychophysical well-being, but also useful allies to combat climate change. Tanner Springs Park (www.urbangreenbluegrids.com/projects)

Building Resilience through Green-blue infrastructures

In 2011 and 2012, the Manhattan district was hit by hurricanes Irene and Sandy, both

causing serious damage to the city. In 2014, the State of New York launched the public competition “Rebuild my Design” to find the best solutions to protect Manhattan: the competition was won by the Danish-American architectural firm BIG (Bjarke Ingels Group) with the BIG U. project. The BIG U proposal is aimed at protecting Lower Manhattan from floods, storms and the consequences of climate change. The project consists of the construction of a 16 km long green barrier, raised above sea level, in the southern tip of Manhattan that will be obtained thanks to a massive pour of soil on the coast. An underground canalisation system is also planned which will collect water from excessive rains and floods and will drain them towards the sea.

Water managment and green blue networks as resilient tools

The problems, the mutations and the mitigation and adaptation systems that the cities of a not-too-distant future will have to face, bring into play interesting themes also from the design point of view; it is right there, where the theme of sustainability becomes stronger, that the designer must demonstrate that he has something extra and that he knows how to work to create systems at the service of the city. The heart of sustainability lies at the urban level, because it is the city that moves the

aspects of the environment, the economy and above all social relations. The design approach of BIG to the project for Manhattan is based on the ambitious principle of creating a barrier between the city and the water that does not arise in terms of a limit, but instead embraces the two entities to create a relationship from which different situations and opportunities emerge. And it is precisely the diversity of the spaces that are created that make the link

The BIG U (www.lafargeholcim-foundation.org/projects/the-dryline)

Building Resilience through Green-blue infrastructures

between the urban space and the defense infrastructure interesting. BIG U aims to transform critical issues into an opportunity for architectural development and urban redevelopment, promoting possible solutions against the destructive effects of climate change and thus electing the Big Apple as the first prototype of a project of this kind, potentially exportable. also in other areas with similar problems to be solved.

seum, consisting of four structures lying on the coast, from which one can observe the rising of the sea. Thanks to this project, it could thus dialogue and interact more and more with the daily life of the city and will provide a resilient urban habitat.

The inner part of the park will be developed in multi-level green areas that will host pedestrian areas, cycle paths, skateboard ramps, new premises for commercial, recreational and cultural activities and construction. The most extreme point of the island will also host the new Maritime Mu-

The BIG U (www.lafargeholcim-foundation.org/projects)

Water managment and green blue networks as resilient tools

2.1.3 ASIA

(attributed to the heat island effect) and projected or already existing sea level rise.

Climate adaptation strategy Country: Vietnam City: Ho Chi Minh City Year: 2013 Ho Chi Minh, aerial view (vietnam.travel/places-to-go)

The city of Ho Chi Minh City (HCMC) is located in the area of the Saigon River delta and Dong Nai. It is the largest city in Vietnam and an important economic, commercial, cultural and research center, both within the country and in Southeast Asia.

million in 2010. The regional economy has grown steadily with double-digit growth rates and HCMC contributes almost 30% to the national GDP and received 37% of total direct foreign investment in 2009.

The HCMC has a diverse topography, ranging from predominantly agricultural and rural areas of the north to a widespread system of rivers, canals and dense mangrove forests to the south.

HCMC faces major challenges in terms of infrastructure development, public transportation, flood prevention and the provision of other public services due to its rapid growth. These challenges will be amplified, given the expected changes in climate.

Like other mega developing cities in Southeast Asia, the city of Ho Chi Minh has undergone rapid changes in recent decades. The cityâ&#x20AC;&#x2122;s population more than doubled, from 3.9 million in 1989 to around 8

The main climatic challenge is urban flooding due to heavy rains and insufficient drainage capacity, aggravated by the rapid urban development that occurs in the low plains, the higher frequency of heavy rains

Building Resilience through Green-blue infrastructures

Urban floods have become a widespread phenomenon and one of the main concerns of HCMC in recent years, which has accompanied the rapid growth of the city. Especially since the early 1990s, the number of places flooded, the frequency of floods and the duration of floods have steadily increased and have caused significant economic and social losses, such as damage to infrastructure and assets, pollution of the water and traffic jams. Vietnam in general and HCMC in particular, have been identified as one of the most affected by future climate change and, in particular, sea level rise. In recent decades, changes in the regional climate have already been observed. The average annual temperature has increased by 0.6 degrees in the last seven decades. Although the annual rainfall volume has remained stable, the number of heavy rains (> 100 mm of rainfall) has increased considerably. Sea level has increased 20 cm in the last 50 years with a velocity of approximately 3 mm per year in the period 1993-2008. It is expected to increase another 28-33 cm by 2050, which represents a great challenge for the lowlying Ho Chi Minh. Today, about 60 percent of the urban area is less than 1.5 meters above sea level, which makes it highly vulnerable to rising sea

levels. This also increases with the sinking of the soil of several centimeters per year in some parts of the city. To address these multiple impacts related to climate change, HCMC adopted its full climate adaptation strategy in April 2013, as part of the â&#x20AC;&#x153;Moving to the sea and adapting to climate changeâ&#x20AC;? project launched in 2011. This integrated strategy includes six directions: 1) creating a smart urban density with connected living and working areas; 2) develop gradual flood protection measures at multiple scales; 3) avoid local flooding of rainwater by improving the drainage and storage system; 4) reduce salinization problems by moving the upstream water outlets; 5) and reduce the subsidence of the soil by limiting the extraction of groundwater and improving the quality of surface waters; 6) reduce urban heat stress through the development of the green-blue urban network. Currently being implemented, the climate adaptation strategy has divided the city into implementation zones, with pilot projects underway in each. The pilot activities include the transfer of the port infrastructure of the dense urban area, which opens the space for climate adaptation measures, including improvements in the urban landscape, such as rainwater mitigation parks, towards the sea and the low-laying areas.

Water managment and green blue networks as resilient tools

These low-laying areas and the new port facilities are adapting flood protection measures, as they are located outside the planned embankments. The broader strategy of the city is complemented by other measures, including: 1) a mandate for all new developments to rise from 2 to 2.5 m above the average sea level; 2) a polder system that will be built around

the city with about 200 km of dams and hundreds of tidal gates; 3) and workshop on community-based adaptation (early warning systems in communities and planning of evacuation routes and drainage channels); 4) in addition to the ongoing research conducted by the University of HCMC on the modeling and simulation of probable cities of possible floods.

Jakarta Water Management Strategy 2030 Country: Indonesia City: Jakarta Year: 2012 Jakarta, aerial view (www.shutterstock.com/it/search/jakarta+skyline)

Jakarta, with 9.6 million inhabitants in 2010 and around 10.2 million in 2014, is the largest city in Indonesia and its capital. Jakarta is located in a lowland area with a relatively flat topography in the delta of several rivers, the main one being the Ciliwung River. Due to its location naturally prone to flooding, the city has a long history of coastal and river flooding. The tropical climate of Jakarta is characterized by high temperatures throughout the year of 24-33 Â° C. The city has frequent storms of high intensity and of short duration, especially in the evenings and nights. The highest total precipitation observed during a month in Jakarta is more than 800 mm. Flooding in Ho Chi Minh (e.vnexpress.net/news/news)

Building Resilience through Green-blue infrastructures

The city is also a growing and economically

active city. GDP projections for Indonesia as a whole show overall growth rates of 4.5% per year between 2005 and 2030, and the population of Jakarta is expected to grow from 8.8 million to 25 million by 2025. The average annual temperature in Indonesia has increased by approx. 0.3 Â° C during the 20th century and the average annual rainfall decreased by approx. 2-3% throughout Indonesia. However, extreme rainfall events will increase in severity and frequency in the 21st century. In addition, in Southeast Asia, tropical cyclones are expected to increase in intensity, which could lead to an increase in storm heights. The rise in sea level is currently underway at a rate of approx. 1-3 mm (0.04-0.12 inches)

Water managment and green blue networks as resilient tools

per year in the coastal areas of Asia, and is expected to accelerate in the future. However, rapid rates of land subsidence play a more important role in the relative change in sea level: recent estimates suggest an average sink rate of 40 mm per year in Jakarta and in some places of the north from Jakarta up to 20 cm of subsidence per year. This is probably due to the high volume of groundwater extraction from the middle and lower aquifers, with secondary contributions to the load of buildings and constructions and the natural consolidation of the sedimentary layers. The high population growth is likely to further intensify the already severe land use pressures that play a role in the floods. Jakarta faces conflicting interests in land use and other problems that cause land invasion, such as informal settlement, where protection areas are needed for flood protection. The priorities of the city are the adaptation to climate change and the increase of social inclusion. Through the 2030 Space Plan, the 2030 Water Management Strategy of Jakarta and the 2030 Climate Adaptation Roadmap, Jakarta aims to promote a safe and sustainable city. A key element is the prevention or reduction of annual floods, caused by rising sea levels, storm surges and subsidence, but also by insufficient flow and infiltra-

tion capacity of Jakartaâ&#x20AC;&#x2122;s waterways (due to the illegal garbage obstruction and insufficient blue-green networks). This is the reason why Jakarta launched the Social Rehabilitation Project for Urban Rehabilitation, which aims to relocate almost 400,000 illegal abusers from the banks of the river and reservoirs close, within â&#x20AC;&#x153;a humanized and participatory processâ&#x20AC;?. As part of the pilot project, the Jakarta government has already built 14,201 units of new apartments for the goal of 52,656 units by 2017 and has transferred some 50,000 people to low-cost housing subsidized by the government. This allowed Jakarta to expand and deepen the Pluit reservoir to increase water storage capacity and develop surrounding green spaces to improve water infiltration. The project also offers multiple collateral benefits, including the improvement of livelihoods and health conditions for transferred citizens, carbon sequestration and the reduction of urban pollution.

with the leadership of the Governor, officials, the private sector and community leaders, as well as the Communication campaigns and intensive public information. These campaigns should address, in particular, the problem of residents who were not accustomed to living in rental housing and the reluctance to move without compensation fueled by a lack of knowledge about the

benefits of new housing. Another reason for success was the public-private system, in which private companies with real estate development permits in the area in question were obliged to participate in the project under a cross-subsidy scheme.

Finally, the reduction in the frequency and duration of floods, combined with a smaller number of people living in flood prone areas, helps to prevent epidemics, such as malaria and typhoid fever. The success of the government in addressing the opposition of the initial residents to the project is largely based on the multi-stakeholder approach of the community,

Building Resilience through Green-blue infrastructures

Flooding in the coastal sea wall in Kali Baru, North Jakarta. (www.straitstimes.com/asia)

Water managment and green blue networks as resilient tools

Green and Blue Space Conceptual Framework Country: Cina City: Hong Kong Year: 2016 Copenhagen, aerial view (www.flickr.com/photos)

Hong Kong is a city well equipped with green spaces and blue water resources, such as rural parks, public parks, ports, beaches, rivers and streams, wetlands, reservoirs, etc. These green and blue assets gradually increased through deliberate government initiatives. Green and blue resources are considered vital and multifunctional components for sustainable urban development. They perform various tangible and intangible functions. In a compact city like Hong Kong, green and blue resources should be exploited to promote a high-density, livable city. Habitability refers to elements of a city that contribute to the quality of life and well-being of its inhabitants. The high-density compact development mo-

del has made Hong Kong an extremely convenient, efficient, vibrant and diverse place with large green and blue spaces. A high-density setting could although have various side effects. Therefore, it is important to establish a coherent conceptual framework to guide the planning of green and blue spaces. The green and blue spaces have played a key role in shaping the fundamental character and identity of our city: from the precolonial era of fishing and rural villages to the metropolitan city of the time.

the valleys of the estuary define the shell of the first settlements.

sources and to improve them and create a synergy with open spaces at various levels.

The current development is concentrated along the reclaimed coastal lands and the new cities are also defined by the green waters, the river valleys, the waterways and the port. The green and blue spaces are integral parts of a compact habitable city. Green spaces are and must remain the “lungs” of cities. It is well known that these “lungs” play an indispensable role in carbon sequestration, pollution improvement, noise reduction, rainwater management and also to alleviate the urban heat island effect, improve the microclimate , improve biodiversity and provide visual relief

The plan requires to enrich even more the landscape values of the urban fabric by enhancing green spaces in built-up areas, particularly areas with a relatively small vegetation cover. Efforts should be intensified to provide a softer and greener landscape in densely populated areas, which are generally affected by the effect of urban heat island, air pollution and noise and limited public facilities.

Hong Kong has abundant green and blue resources and an integrated approach to planning must be adopted for greater benefits and synergies. There are opportunities to make the best use of the existing re-

Having considered the intrinsic quality of green and blue spaces in Hong Kong and in view of the city’s challenges, namely the change in the demographic composition, the exponential growth of the demand for medical care, the growing aspiration to improve the quality of the environment of life , competition for land and other resources and climate change, the fundamental principles of planning for green and blue spa-

The green hills and undulating topography form the backbone, and the harbor and watercourse form the supporting structure. The coast, the hills, the alluvial plains and

Building Resilience through Green-blue infrastructures

Water managment and green blue networks as resilient tools

ces are: 1) improve and manage valuable green and blue resources; 2) connect and reinvent spaces to promote the public use of synergy and imagination; 3) connect people with nature and cultivate the communityâ&#x20AC;&#x2122;s green resource system; is 4) participate in sustainable and sustainable use of resources in city infrastructure planning.

Under the principles, five strategic directions are recommended by the plan: 1) enriching existing green-blue assets; 2) reinventing the â&#x20AC;&#x153;green and blue systemâ&#x20AC;? networks; 3) cultivating the community greenery grid; 4) developing an urban forestry strategy; 5) promoting a sustainable built environment.

Bangalore Urban Metabolism Project Country: India City: Bangalore Year: 2011 Bangalore, aerial view (www.asiagreenbuildings.com/13478)

Bangalore, in southern India, has grown rapidly in recent decades, going from a population of 1.65 million in 1971 to around 8.5 million in 2011. Despite the numerous economic developments in Bangalore, the city suffers from chronic shortages of basic services, such as energy and water and has serious problems related to traffic. In addition, the natural environment in Bangalore and its surroundings has degraded, reducing ecological sustainability and the basis for resilience in the city.

Existing Green and Blue Assets in Hong Kong (Green and Blue Space Conceptual Framework)

Building Resilience through Green-blue infrastructures

Water resources are a major concern for the ever-expanding city of Bangalore. Limiting the ability to correctly plan water services was limited by the lack of knowledge of the amount of water that was used in the city. There has been a data gap for both the

demand side, in terms of what urban residents use and what they need. Information on marginal prices is not available to residents of Bangalore and, therefore, price signals do not alter the behavior of water consumption. Detailed assessments were also lacking regarding the water supply. Although it is known that the public water supply comes from the Cauvery River, which is 100 km from Bangalore, the city is already withdrawing its full legal limit. This public water supply currently covers less than 50% of demand, so groundwater is also used and groundwater levels, recharge-discharge dynamics or safe yields have not been studied in detail. The lack of evaluation of groundwater has

Water managment and green blue networks as resilient tools

also meant that groundwater policies do not exist or are poorly informed. The Bangalore Urban Metabolism Project is an innovative project, supported by the Cities Alliance and implemented by the Stockholm Institute for the Environment, to use metabolic structures to understand cities and design more sustainable futures. Specifically, this framework was designed to improve the integrated management of water resources in Bangalore based on multidisciplinary perspectives and skills, from hydrology, social sciences, economics, engineering and computer science.

rent perspectives of the interested parties, which is why it has been integrated into the project. The culmination of this work will be an integrated model of water resources that will support more sustainable planning and management of water resources that can meet the needs of the urban poor and support the conservation of critical freshwater ecosystems.

The project worked to address the challenges related to improving access to water and building resilience highlighted in the previous section. In order to increase data and understanding of the demand side of water resources, the project analyzed domestic water demand through surveys that showed that the urban poor pay much more for water of lower quality.

Water crisis (www.technologyreview.com/s/613344)

Using a network-based sampling project, the project mapped groundwater and used the 1-D and 2-D models to better understand the availability of groundwater in Bangalore. The consultations of the neighborhood at national level have been fundamental to raise awareness and understand the diffe-

Building Resilience through Green-blue infrastructures

Water managment and green blue networks as resilient tools

The city has set the goal of achieving 0.8 hectares of green space per 1,000 people by 2030. Many of the reservoirs and waterways will have a more natural design and will be open to the public. As of 2008, all new buildings must comply with the “Green Mark” standard.

New Water Project Country: Republic of Singapore City: Singapore Year: 2006

The objectives in terms of the city’s water system have been translated into several programs, including ABC’s Water Design Guidelines (“active, beautiful and clean”), which define a vision of green-blue networks to be developed and strengthened in the city.

Most systems involve ecological forms of water retention and treatment and solutions that have been correctly integrated into the environment. The design is a chain of structures that we would describe as ditches, biospheres, retention ponds and wetlands, as well as containment structures below and along the roads connected to the larger rivers. The integration of structures in the urban system means that the program depends on the participation of residents. This is an aspect that is actively promoted.

Copenhagen, aerial view (www.flickr.com/photos)

Singapore is a city with one of the highest population densities in the world. Singapore is a country with an area of more than 680 km2 and a population of almost 5 million people. This state of densely populated city has set itself the goal of creating an ambitious and comprehensive program to increase sustainability and quality of life. Although the approach adopted is specific to the situation in Singapore, it is also interesting for other urban conglomerates. The problems related to the nature in Singapore are various: 1) Its sources of drinking water are scarce. 2) Singapore has virtually no raw materials on its land. This is more of a problem at this time when raw materials are scarce all over the world

and prices rise accordingly. 3) Singapore is in a delta and is continually threatened by fluctuations in water levels. 4) The population is relatively well educated compared to other Asian countries and has high demands in terms of living environment. The objective of Singapore is to ensure that the measures taken to solve these problems translate into the highest quality of life for each Asian city. This refers to a sustainable and thoroughly used city that is green, clean and offers an excellent infrastructure. By increasing the level of sustainability of the city, Singapore will also achieve high quality in spatial terms, which will allow continued prosperity and growth in the future.

Building Resilience through Green-blue infrastructures

The canals of the city will be transformed into green-blue grids. In Singapore’s tropical climate, rainwater falls in a short period of time and drains into concrete canals. These canals form barriers in the city and are inefficient. The green-blue grids include the city’s water tanks, canals and rivers, and connect to the grids and green parks of the city to buffer and treat rainwater. Green grills offer opportunities for recreation, reduce heat stress, transport slow traffic and, of course, create a more attractive city. A recent publication, Design Guidelines, describes the design principles of ABC’s water design guidelines and presents the details of the various subprojects. The design elements are divided into retention structures, treatment systems and retention systems.

The ABC plan includes 100 subprojects, of which 20 will be completed by the end of 2012. One of the main pilots is the Marina Barrage: this project performs important functions, such as a reserve of clean water, recreational area and flood protection for the city. The visitor center of Marina Barrage houses an exhibition that offers information to visitors about water projects. The building also houses a restaurant and has a green roof to keep the building cool and reduce air conditioning costs. The vision is to transform Singapore into a city of water, parks and gardens and create possibilities for outdoor activities and sports. Another important project concerns the improvement of the connection between the Kallang River and the city and the parks

Water managment and green blue networks as resilient tools

Bishan Park and Kallang River restoration (anyflip.com/amtj/ugqe/basic)

Marina Barrage (www.pub.gov.sg/marinabarrage)

adjacent to the river. For example, the river, which flows through a concrete bed, has returned to a more natural appearance, given the green banks and facilitated access and access for the inhabitants of the city. The aim of the New Water project is to eliminate Singaporeâ&#x20AC;&#x2122;s dependence on Malaysiaâ&#x20AC;&#x2122;s drinking water supply. To achieve this, all wastewater in the city is treated with membrane filtration. The treated wastewater is used mainly for industrial purposes and

replaces 30% of the drinking water. Captured rainwater is another important source for the production of drinking water. A large seawater desalination plant is the final element in the drinking water production system. In addition to the ABC program, Singapore has also defined a strategy for climate change, which deals with mitigation, heat stress and biodiversity. [Climate change strategy, 2008]

Building Resilience through Green-blue infrastructures

As part of the process of increasing the amount of vegetation in the city, Singapore supports private initiatives for the construction of traditional gardens and hanging gardens. For example, the city already hosts more than 300 shared gardens. There are incentives for building green roofs to keep buildings underground and help reduce the amount of energy used for air conditioning. The large amount of vegetation in the city also serves to keep the city cool as water-borne diseases, such as dengue, are more common in regions with high temperatures. Biodiversity is another issue to which the city is dedicating attention, researching and protecting corals and mangrove forests, which are at risk due to sea level rise.

Singapore treats and recycles all its wastewater. The heat is extracted from wastewater and organic material and recycled. The city has strict policies to prevent pollution and a regime for the separation and recycling of waste. Singapore is showing what can be achieved in a densely populated area and is showing possible solutions for the times when not only fossil energy sources will be scarce, but also fresh water supplies. The deliberate decision to combine greater sustainability with a better quality of life demonstrates a reasonable approach to managing climate change.

Water managment and green blue networks as resilient tools

2.2 is it possible to define a common ground?

Building Resilience through Green-blue infrastructures

The projects analyzed above offered a broad view of the possibilities and choices that could be made regarding the issue of water management. Depending on the geographical areas, different climatic and environmental problems have been identified and consequently it has been possible to observe how the undertaken solutions were among the most disparate. However, all the projects started with the common goal of finding a solution to the problems generated by climate change and the objective of adapting a city to the future. Urban resilience is the main theme shared by the analyzed projects. Climate change has affected cities in many ways due to increasingly frequent rains, sea level rise, rising temperatures and extreme heat waves. In all the examples it has been recognized how green networks (eg gardens, parks, roofs and green walls) and blue networks (eg water bodies, drainage systems, rivers, streams) help to constitute a sustainable and cost-effective strategy to strengthen urban resilience through moderating urban temperatures, regulating water flow, controlling floods, improving environmental capacities and resilience, mitigating and adapting to climate change and dangers arising therefrom. It is unanimously recognized that blue spaces contribute significantly to the

environment and play an ecological, aesthetic and functional role. Both green spaces and blue spaces have an important aspect in improving the quality of life and well-being of people. They have also been outlined as crucial elements to improve the attractiveness of cities in a world where tourism is increasingly competitive. Almost all the projects have among their main objectives the transition from gray to green-blue infrastructures, to guarantee environmental, social and economic benefits. The blue-green nets could complement the current drainage systems, trying to prevent their enhancement or at least trying to delay their construction. All the analyzed cities underline the importance of undertaking an integrated approach during the planning phase, to have more benefits and cooperation. Opportunities are sought for making the best use of existing resources and improving synergy with open spaces on multiple levels. Among the common objectives, a significant importance is given to the enrichment of the landscape value of the urban fabric, highlighting the green spaces in the built areas and in particular in the areas where these are meager. In the case of Asian cities, efforts are often

Water managment and green blue networks as resilient tools

channeled to obtain greener and softer landscapes, within densely populated urban contexts. These areas are also particularly affected by the heat island effect, air and sound pollution effects and have insufficient public services. All plans are to undertake a holistic approach in re-introducing water as a resource in the urban context, integrating and correlating waterways, canals, green spaces, parks and urban areas. Both the green and blue spaces are therefore important landscape resources and urban planning elements that provide the characteristics of the landscape that can offer breath and visual relief in a compact urban environment. It is rare nowadays that in a city there are rich green-blue resources in proximity of the urban core, which can allow an urban life that is simultaneous with a harmonious coexistence with nature. A common line has also been identified for the enhancement of the natural elements within the landscape, making it prevail over purely artificial interventions. At the base of this idea there is the recognition of natural elements such as vegetation, bodies of water and natural landscapes as territorial heritages. The decrease of natural elements leads to a decrease in the ecological sustainability of the city and consequently of its resilience.

With regard to urban green and blue spaces, nature-based solutions can foster and simplify implementation actions in urban landscapes by taking into account the services provided by nature (Secretariat of the Convention on Biological Diversity 2009). IUCN (International Union for Conservation of Nature) defines nature-based solutions as: “ [… ] actions to protect, sustainably manage and restore natural or modified ecosystems, which address societal challenges (e.g., climate change, food and water security or natural disasters) effectively and adaptively, while simultaneously providing human wellbeing and biodiversity benefits” (CohenShacham et al. 2016). What the European Commission has stated on this topic is that: “ […] nature-based solutions to societal challenges as solutions that are inspired and supported by nature, which are cost-effective, simultaneously provide environmental, social and economic benefits and help build resilience. Such solutions bring more, and more diverse, nature and natural features and processes into cities, landscapes and seascapes, through locally adapted, resource-efficient and systemic interventions” (European Commission 2016). The natural layout of the territories can be restored by including bodies of aquatic elements, reintroducing groundwater and planting adequate vegetation.

Building Resilience through Green-blue infrastructures

Examples of nature based solutions include provision of urban green such as parks and street trees that may ameliorate high temperature in cities (Gill et al. 2007; Bowler et al. 2010) or regulate air and water flows. Allocation of natural habitat space in floodplains may buffer impacts of flood events. Furthermore, architectural solutions for buildings, such as green roofs and wall installations for temperature reduction and related energy savings through reduced cooling loads (Castleton et al. 2010), The suggested design approach prefers to restore a more natural and organic aspect of the landscape, which can protect and enhance plant and animal biodiversity. A coherent and interconnected system of green and blue spaces contributes to improving biodiversity and essential ecological services because they act as ecological habitats and corridors that connect wildlife habitats, preserve the natural environment and increase carbon storage.

of the surrounding air. Green-blue spaces have been identified as opportunities to provide recreation areas for residents and visitors, becoming important attributes of the public sphere. They can also cover the role of promoters of a healthy lifestyle and raise awareness of environmental issues. Parks can offer a space for interaction and socialization for the inhabitants. In many projects it has emerged as with better water quality and proper planning and management, urban spaces, such as rivers and streams, drainage canals and coastal areas, can also be used for recreational, sporting and recreational purposes.

The vegetation can also influence the temperature of the surrounding air, pedestrian sun exposure and the wind speed in the streets. It increases the dynamic potential and helps to mitigate the thermal load and the effect of the urban heat island. The evapotranspiration process in plants absorbs large amounts of heat from the air that cools the temperature

Water managment and green blue networks as resilient tools

Building Resilience through Green-blue infrastructures

Water managment and green blue networks as resilient tools

03| |ABSTRACT ANALYSIS

3.1 current threats to a resilient dhaka

The major problem that endanger Dhaka and obstacle its path towards resilience are linked to two main fields: environment and density. In fact Dhaka presents many environmental issues due to its geographical location and to the effects of its rapid and unplanned urban growth. The high population density creates itself urban issues but also exacerbates the environmental problem already existing. The two categories of environmental and density issue will be investigated separately to provide a clearer and easy-to-follow analysis but they are interrelated and problems from each one influence and boost the issues from the other. 3.1.1 Environmental issues Dhaka is located in the Ganges-Brahmaputra Delta, the biggest delta system of the world, consisting of Bangladesh and the Indian state of West Bengal. where rivers from Bhutan, Tibet, India, and Nepal flow from the north on their way to the Indian ocean. Dha-

ka is in fact bounded by 4 rivers: the Bulgarian River, Turag River, Dhaleshwari River and Shitalakshya River. Dhaka has a subtropical monsoon climate characterized by wide seasonal variations in rainfall, high temperatures and humidity. There are three distinct seasons in Bangladesh: a hot, humid summer from March to June; a cool, rainy monsoon season from June to October; and a cool, dry winter from October to March. Heavy rainfall is characteristic of Bangladesh especially during the rainy monsoon season, when 80 percent of rain falls. Bangladesh has also a typhoon season that begins in August and lasts to end November. Typhoons have often catastrofal effects, and can cause floodings that can sometimes last for several weeks. Because of its geographical location and its climate Dhaka is required to manage outstanding amount of water that can reach the city in the form of overflow from the

Analysis

precipitations will be more concentrated from May to July, and after this peak, a slight decrease will be registered for July, August and September. Also the temperature will rise in the urban area, putting the city in a more stressful condition. In fact examining the projection for the maximum temperature in Dhaka until 2099, it is clear that city will be significantly hotter. A slight fluctuation and decrease will be registered in the first two month of the years, while they will remarkably increase from March to December. In summer the growth will reach over 5 degrees Celsius and there will be a shift of the hottest period of the year. In fact nowadays April is hottest month of the year, but in future its temperatures will be overcome in June, August. Dhakaâ&#x20AC;&#x2122;s geographical location, climate characteristics and rapid urban growth rate have led to significant environmental issues. In addiction the projections for the future suggest that some of the problems will be further worsen by the changing climate, that will also create new dangers. surrounding rivers and of rainfall. If the average yearly rainfall of Dhaka is compared with the ones of different big urban areas from Europe, America, Asia and Oceania, it can be clearly understood how considerable is the amount of stormwater with whom Dhaka has to deal. In fact registering around 2000mm of rainfall per year it is the 74

city with the biggest average yearly rainfall in comparison to Paris, Rome, Cairo, Tokyo, Sydney, New York. According to projections until 2099, the amount of rainfall is expected to increase. In particular it will rise in each month of the year except from July to September, In fact

Building Resilience through Green-blue infrastructures

The most relevant environmental issues that the city is already facing is waterlogging. Urban waterlogging is a condition in which stormwater falling in the form of rain on the urban surfaces can not be drained in a proper period of time. Under this condition stormwater get stagnant and streets and other open spaces get flooded. This hap-

pens when the amount of stormwater that the city receive as rain is bigger than the capacity of its drainage system. Dhaka has been experiencing a gradual increase in water-logging over the last decade. Moderate to heavy rain causes serious drainage Problems in many parts of the city with knee-deep water on the streets. During heavy rain periods Dhaka gets rapidly flooded with detrimental effects on traffic, economy and daily life. Water logging and temporary inundation in parts of Dhaka last for several days during monsoon. This phenomenon will be analyzed in details in the following paragraphs. A significant danger that the city will face in the coming years is the rise of temperature caused by climate change and by the enhancement of the urban heat island effect due to additional urban growth. This phenomenon will act as a chronic pressure to the city, but will also lead to acute shocks in the form of heat waves. In both forms this termite stress will increase the energy demand, make fires more likely to happen, worsen the air-quality and reduce the biodiversity. In addiction it will make daily activities harder for the underprivileged groups. For examples groups who work on the streets such as rickshaw pullers or vendors will face a tougher work environment while people who live in informal settlements or that do not have access to air conditioned spaces will live in a condition of discomfort. Extremely acute events can even put at risk

Analysis

the life of the most vulnerable such as the elderlies and young children. Currently, groundwater is the main source of water supply in urban Dhaka, with about 80% of water produced by Dhaka Water And Sewerage Authority (DWASA) is currently sourced from aquifers. According to a resources assessment study conducted in 2006 the overexploitation of groundwater induce a draw-down of 15m per year. From this figure it is clear that Dhaka is extracting groundwater at a higher pace than the recharge process, clearly exploiting this resource in an unsustainable way. The availability of groundwater for drinking purposes, however, has become a problem also for the excessive dissolved Ammonia, excessive amount of iron and manganese in the ground water. Thus the deeper aquifer is no longer dependable as a long term sustainable water source and anyway this excessive exploitation of groundwater needs to be reduced to stop the continuous decline of the water table. On the other hand the current pollution of surface water imped its exploitation as clean water source. In fact surface water receives pollutants from agricultural, industrial and domestic sources. Insanitary practices of people have greatly contributed to the deterioration of quality of surface water. The fecal coliform concentration in most surface water sources in the surrounding peripheral rivers is very high. Thus the use of surface

Building Resilience through Green-blue infrastructures

water for drinking purpose requires purification and disinfection by elaborate treatment processes but the scarce availability of surface water in the dry season is also a constraint for the development of dependable Small and large scale surface water treatment plants for safe water supply. Dhakaâ&#x20AC;&#x2122;s fast growing population and concentration of services and industries and higher consumption of natural assets and resources are the key factors responsible for degradation of ecosystems and biodiversity. This situation is compounded by the effects of climate change. Another serious issue is the lack of green space, that affects negatively the life quality of city dwellers and compounds the already severe environmental problems. The lack of green spaces means that most of the city is built up and little space is left to natural ab-

sorption of excess water by the soil and plants, thus it exacerbates waterlogging. Furthermore it means that most of the city consist of thermally absorbent artificial materials, which boost the Urban Heat Island Effect and that no shade is provided to the inhabitants. A reduced amount of green spaces also involves difficulties in maintaining biodiversity and ecosystems.

Analysis

3.1.2 density related issues Dhaka is the world’s 19th largest metropolitan area and with a density of 47,400 people per square kilometer, in 2018 has ranked the most densely populated city on earth in the 14th annual edition of “Demographia World Urban Areas”. The population of Dhaka is increasing every day as people move into the city from different areas across the country to avail facilities. Government estimates say that at least 1,418 people are adding to the population of Dhaka every day, with the current population at over 17 million marking the city as the densest city on the globe. Dhaka has ranked first place for three consecutive years and a rise in density of 4,2% up has been registered from 2017. Experts consider the rising trend in Dhaka’s population alarming. They have pointed out migration and lack of policy for effective land use, poor coordination between ministries and divisions, and initiatives to make Dhaka more attractive, as some of the reasons behind the rising population density. The historical process of urban development in Dhaka City presents different trends based on its political development. Dhaka developed as a politico-administrative city and subsequently economic and commercial activities have also concentrated in the city making it the prominent city of the country. The urbanization activities in Dhaka City

have been achieving tremendous growth for the needs of the newly independent country’s capital. Overall, Dhaka City has experienced its highest rate of physical and population growth in recent decades that transformed it into a megacity. In fact Dhaka today host 1/3 of the urban population of the country, and produces 1/3 of the national Gross Domestic Product. As claimed by different demographic experts, people tend to move to Dhaka because it offers better schools, universities, hospitals, and other facilities that are absent in the rural areas. The city is also considered the industrial and commercial center of Bangladesh with its trade in such goods as jute, rice, sugar, and tea, as well as for its thriving textile industry. The vibrant economic life of the city allows almost everyone to have discreet earning possibilities. The poorest coming from the rural areas can become rickshaw pullers, vendors and maids, while educated people move to the capital looking for professional opportunities. A large number of Dhakaites work in the household or unorganized labor, while a substantial portion (approximately 800,000) work in the textile industry, as Dhaka’s garments exporting topped over 19 billion dollars in 2013.

Building Resilience through Green-blue infrastructures

Analysis

Despite the apparent availability of jobs in the city, approximately 23% of the population was unemployed according to data from 2013, with an estimated 34% of households living below the poverty line. Migration from rural areas of the country to urban Dhaka is an active contributor to the population growth. This rural migration accounted for 60% population growth throughout the 1960s and 1970s. While this growth has slowed since that time, Dhaka continues to show steady growth, with estimates placing the 2020 population at almost 20 million, while 2030 may see as many as 24.5 million residents. In the projection in the Dhaka Structure Plan 2016â&#x20AC;&#x201C;2035 (RAJUK 2015), the cityâ&#x20AC;&#x2122;s total population is supposed to reach 26.3 million in 2035, the equivalent of 2.3 % growth a year from 2011. The fast-growing population has already put tremendous stress on the city, as evidenced by its high rates of poverty, and future concerns include increasing congestion, a higher percentage of unemployment and inadequate infrastructure. High population growth in the urban centers, especially in the capital city Dhaka, is in one hand generating increasing demands of infrastructures and in the other hand exacerbating hazard induced risks. Lack of law enforcement and monitoring resulting in poor construction standards, construction

on filled up canals and water bodies, unplanned-uncontrolled growth in hazard prone areas, increasing slum settlementsall of these are turning the whole city into a source of potential hazards. Faster growth of cities with insensitive or noninclusive urban land use planning, urban development and management lead to higher disaster risks (Sharma 2011). As a result, incidences like fire, water logging, and collapse of structures are evident in the built up areas; and the persisting uncontrolled growth is posing threat of higher mortality due to collapse, fire and earthquake as well. Besides, the unplanned development is delaying post disaster response activities. According to the 2011 Census, the population of Dhaka is living in an area of 316 sq km and the number of households is 2 034 146. During the last three decades Dhaka city expanded both horizontally and vertically (Ahsan, 2013). The city developed spontaneously without observing any rigid planning guidelines or regulations, has exhibited a series of informal and organic spatial patterns (Nilufar, 2016). The intervening ditches, swamps and marshes were filled in, not in any planned manner, but as the demand arose and private initiatives dominated the process (Haque, 2003). The central part of Dhaka city is already built up and its expansion is restricted by

Building Resilience through Green-blue infrastructures

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tium faccatem ea poribuscius essint. Omnia et lam dolupta il il iuscia que estiisqui doloreped quosto volupti untur, optatiat quodit ium sant. On natem diatquiae. Abo. Nam recum aut andelent aut earum intotae commo ommos nost, ullab ipidit, quis simaio ipsa quiscim sit iunt dempori buscillaces sitio quatiorro et estrum re, sequaese ex et officat. Tem facienit as si archil mos ex et por alitaestem ius et aliqui volupicatur sit, numqui doluptatium ex endipienest, sam fugiatemque velendio torehenda sam none de niae sapel mod quo officiunt, quame ommolum quident. Usda vidus. Abo. Itatis molupta quid utatem ne nusa dolutem esti tectem qui odi di ut facerio nemquat ea et maio veria nonet aceaquibus con conseni rem ra voluptate alignim voloriti rerovitia perum re plate omnis dit quam recte num sit occate maximus et laborio esed mint prorerrovid quo tenimus que et offic to tem nihitatur? Peliae num ideliqui optatur aut as conseni mperibus. Ebiti quam fugit voles quam aut rectur ma sinctem nime nisquae. Tur molum doluptia cus. Tionsequo intinus, ius nos perumque rem inimaximusae num ea sinciumque niet diaes is doluptatur? Qui volumqui nusam corio blam re min parchilis quiaturis pro te sam, tesequibea con nate nonem non evelecu lluptati rempor aut aut quunt molupta tusant quid quis atur at et eumqui non

Analysis

rivers, canals and low lying flood prone areas around the city; however ignoring such barriers Dhaka is expanding towards all direction through rapid development of housing estates (Parvin, 2013). In Dhaka, a critical imbalance has been observed between usersâ&#x20AC;&#x2122; need and aspiration of urban public green space use and the available quantity they benefit from. The city possesses only 5 sq m of public green every 10 people, while it needs to devote a range between 0,025 sq km and 0,043 sq km evry thousand people,

according to NRPA (National Recreation and Park Association recommendation). With the phenomenal rise in the level of urbanization and urban growth, the city suffers the loss of its open space for urban infill. The gap between the amount of open space available continues to widen and as the city keeps on developing, it leaves little scope to have more open space on its inside. The scarcity of buildable land and the demand for other land use, places an immense pressure on land for greeneries

and open areas (Lau, 2014). High building and population densities and incompatible mixing of land use creates crowding, lack of privacy and poor environmental quality (Coorey. 20017). Existing parks and other public green spaces in higher density areas have become so congested with users and have attracted new undesirable and incompatible uses. Because of the limited space, the siting and construction of a new solid waste management facility is a big challenge in Dhaka. A solid waste management

facility should be socially accepted as well as environmentally and economically, so it is considered one of the most serious problems of the city. Almost no sorting is done while dealing with the wastes, that bounds the solid waste management system to cripple and to be unproductive and makes any kind of recycling impossible. Age-old waste transportation system running with inadequate number of vehicles, among which most of these are completely open to the outdoors, cause serious environmental pollution. Moreover,

Density of Dhaka (www.dhakatribune.com)

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Analysis

the absence of composting system causes untreated organic waste to generate serious pollution. The amount of municipal waste that is produced daily in Dhaka city is easily imaginable. However, the matter of concern is that the age-old waste management system followed by Dhaka city corporation and the amount of equipment and workforce are totally in adequate to support this huge population. Furthermore, the illiteracy and unawareness of people is making the condition much more severe. As residential land use involves 36.47% of the Dhaka Metropolitan Region area, roads and railways, that are considered as the most important infrastructure in a modern city, constitute only 2.3% of the total area. Horrendous congestion and delays, inadequate traffic management, poor coordination among agencies, and lack of integration between different transpiration modes characterize the transport sector of Dhaka city. Dhaka is perhaps the only city of the world of this size without having a well-organized and scheduled mass transit system. The traffic condition of the city has presently reached a crisis situation. The everincreasing chaos and congestions, high rate of accidents and rapidly deteriorating environmental conditions calls for immediate considerations of an alternative transport

option that could efficiently reduce the loads on road transport. Following, there is a categorization of transport systems in the city of Dhaka, public and private, responsible for the large congestion within the city. Bus Service The current bus network serves a population of 5.5 million everyday (considering an influence zone of 400m of the transport network) through a road network of 3,800 km, which represents a road density of 3.65 km per sq km. However, several local streets in the old part of city and some new unplanned neighborhoods are too narrow (where rickshaw movement dominates) for bus operation, resulting in only 12.5 % of the entire road network suitable for bus movement. In the study area most of the high capacity roads run north south. Out of 152 bus routes, only 5 bus routes operate east-west. The existing public transport culture creates a low quality service, adding to road congestion and having negative social impacts. Congestion increases the average trip times, which results in higher fuel consumption. The current bus fleet is not environment friendly; about 82% of the buses are diesel fueled due to which air pollution is five times the acceptable limit. Taxi Service Taxi is an important element of urban public transport system, offering a convenient form of alternative transport particularly during off peak hour time. Dhaka is probably the only

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capital city in the world having extremely limited provision of taxis. Taxi service started in Dhaka in 2004 with 2000 taxis, but due to lack of incentive by the government, most of the taxis went out of service within a very short time. Last year two companies have put about six hundred new taxis in the Dhaka streets. However, the fair is not within affordable limit of the majority of the city dwellers. Auto Rickshaw and Tempo There are about 13,000 registered auto rickshaws and tempos in the city. Currently, there is a ban on new registration, which caused plying of illegal auto rickshaws on the streets; as a result, the actual number of this category of vehicle is much higher (2000-3000). These vehicles use CNG as fuel, which is environment friendly. Though there are meters in the vehicles, the fare is actually determined on bargain. However, the fare is not affordable by low-income groups. Peopleâ&#x20AC;&#x2122;s dependence on auto rickshaw will continue until an efficient public transport system is introduced. Railway Within the main city, the railway operates from two major stations, Kamlapur Railway Station (Central Station) and Airport Railway Station (North of Central Station). The railway network of Dhaka passes from central railway station to Narayanganj in south-eastern part and in the northern part up to Tongi junction. From Tongi

junction, one section goes through Narsingdi towards Chittagong and Sylhet other section goes up to Joydebpur and from there, one line goes to north Bengal via Jamuna Multipurpose Bridge through Tangail and another line goes to Jamlapur via Mymensing. Through these three directional lines Dhaka is connected with the entire railway system of the country. Waterway The Sadarghat terminal is the only major river terminal on Buriganga River that connects river traffic of the south-western Bangladesh to Dhaka city. The major inter-district passenger routes connect Dhaka to Khulna, Barisal,Bagerhat, Pirojpur, Patuakhali, Chandpur, Bhola mainly the southwestern region of Bangladesh. There are several on-going projects to improve the river transport system in Dhaka city, but they have been facing several problems such as the absence of feasibility studies before the launch of the projects and the lack of operational plans. Landing station facilities are not good enough and no feeder bus services are provided for waterbus network. Moreover, the traffic jam that could be encountered en route to reach the terminals is Sadarghat and Gabtoli is huge. Private car As ascertained from the Bangladesh Road Transport Authority, the number of registered car (including jeeps and microbusses) in Dhaka is 306,000 with

Analysis

average annual growth during the last five years that varied between 5% to 10%. The growth is very much dependent on import duty. The current contribution of trip by private car is about 5%, even with higher economic growth this ratio is expected not to exceed beyond 8% by the year 2035 due to the introduction of the metro rail line and improved bus systems. Motorcycle Motorcycle population is increasing more than 10% annually. The registered motorcycles in Dhaka till 2013 are 304 000 out of which 50% may not be in use due to old age. The motorcycles are usually on the street during morning and evening peak hours. As observed in other developing countries, their number may increase rapidly in the next few years increasing the risk of air and noise pollution, and the risk of road accident. Rickshaw Manually operated rickshaw is a prominent mode of transport for Dhaka city. There are about 500 000 rickshaws in Dhaka City contributing to 37% of the total trips, and providing jobs to about a million people (in two working shifts). Due to their presence in arterial and main roads, the speed of motorized vehicles reduces to only 8 km/ hour during peak hours, contributing to severe traffic congestion. Large numbers of unaccounted rickshaws are also available in outer urban areas.

Pedestrians Presently, about twenty percent of daily trips (especially short length trips) are walking trips. Most of the CBD area and public utility (education and health) areas are provided with sidewalk of varying width (1m-4m) covering 600 km in length. However, most of the sidewalks in the Central Business District area are occupied by vendors, forcing the pedestrians to walk on the carriageway, thereby creating traffic congestion and safety hazard. Some of the residential areas are provided with sidewalks but newly built areas lack this facility Freight Transport The impacts of freight traffic on urban roadway are a major concern: the movement of the goods or the freight traffic is necessary for keeping business going on and transportation of consumer goods at economical cost. It is estimated that about 70% of containers passing through the Chittagong port are known to originate from or are destined to Dhaka and Narayanganj areas. The Chittagong port handled about 16 million tons of cargo in 2013. About 11 million tons of cargo passes through Dhaka and Narayanganj mostly by roadway (85%). All of this traffic has to use the only DhakaChittagong highway to pass through capital city by trucks and trailers.

Building Resilience through Green-blue infrastructures

Analysis

3.2 a hystory of urban water

Water has always had a fundamental role in the development of the city. In fact being located in the biggest delta of the world and characterized by a rainy monsoon climate, Dhaka has always had to deal with significant amounts of water. The city developed settlements patterns capable of protect the city by excessive water event and of exploiting it as a source of service and communication line. Thus water had a remarkable impact on the spatial development, life and livability of Dhaka. In fact water has been not only a structuring element of the city, but also one of the peculiar aspects of the urban landscape. This strong relationship between water and the city has got almost completely lost during the development of the city in the last two centuries. 3.2.1 Development of the city The first settlements of the city dated around 300, rose on the banks of Buriganga river, on the area that today is occupied by the district of “Old Dhaka”, in the south-east of the metropolitan area. From this little core the city started to slowly grow along the river. The region was part of the Sena Empire, a Hindu dynasty during the Late Classical period on the Indian subcontinent, that ruled Bengal through the 11th and 12th centuries. After its early Hindu period it got under Islamic rule, in particular by the Delhi Sultanate and by the Bengal sultanate. In this first phase of its development which is usually named “Pre Mogul Period”, Dha-

ka used to be a small town compounded by Buriganga river on the south and by the Dolai Kahl that enclosed it on the other sides. This canal is still partially present on the east edge of old Dhaka, while the other parts has been recently substituted by box culverts to transform the canal in a main urban road. The Mogul Empire governed the region from around 1500 to 1750. Under Mogul rule, the Old City of Dhaka grew on the banks of the Buriganga River towards west. Dhaka was proclaimed the capital of Mogul Bengal in 1608 and at that time the city measured 19 by 13 kilometers, with a population of nearly one million. Dhaka was one of the largest and most prosperous cities in South Asia. It grew into a regional economic center during the 17th and 18th centuries, serving as a hub for Eurasian traders and as a center of the worldwide muslin, cotton and jute industries. Dhaka was the commercial capital of the Mogul empire and the Bengal region generated 29% of world GDP at the time. Bengal was an affluent region with a Bengali Muslim majority and Bengali Hindu minority. The city had well-laid out gardens, monuments, mosques, temples, bazaars, churches and caravansaries. The riverbanks were dotted with tea houses and numerous stately mansions. Eurasian traders built neighborhoods in Farashganj (French Bazaar), Armanitola (Armenian Quarter) and Postogola (Portuguese Quarter).

Analysis

With the defeat of the Nawab of Bengal at the Battle of Buxar in 1764, the British East India Company gained the right to collect taxes from the principality of Bengal. The city formally passed to the control of the British East India Company in 1793 and Dhaka got plugged into the imperial mercantile networks of the British Empire. With the dawn of the Industrial Revolution in Great Britain, Dhaka became a leading center of the jute trade, as Bengal accounted for the largest share of the world’s jute production. Dhaka suffered stagnation and decline began during the mid 19th-century. Its industry was destroyed by high colonial taxation, restriction of trade and forced imports of British manufactured textiles. In addition the rise of the colonial capital Calcutta caused a sharp decline in the city’s population and Dhaka became heavily impoverished. Following the Indian Rebellion of 1857-58, the British Indian Rule was established and

the Dhaka Cantonment was created as a base for the British Indian Army. The British developed the modern city around Ramna, Shahbag Garden and Victoria Park, a modern civic water system was introduced in 1874, the Dhaka State Railway was opened with a 144 km rail line in 1885, and some of the early educational institutions were established and Automobiles began appearing after the turn of the century.. At the end of the colonization in 1947, with the so called Partition of India the British domain was divided in two countries on a religious basis: India was predominantly Hindu, while Pakistan was created as a predominantly Muslim country. The Dominion of India is today the Republic of India and Dominion of Pakistan, is today the Islamic Republic of Pakistan (west of India) and the People’s Republic of Bangladesh (east of India). Pakistan was funded as one state

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with two separated territories. The partition displaced between 10 and 12 million people along religious lines, creating overwhelming refugee crises in the newly constituted dominions. Dhaka became the capital of East Pakistan (1955-1971). Dhaka’s urban population increased dramatically because of Muslim migration from across Bengal and other parts of the subcontinent so the city began to see rapid urban expansion from the 1950s and the first masterplan for the city was drawn up in 1959. Dhaka in 1962 was declared as the country’s legislative capital due to the region’s large population. In 1962, President Ayub Khan designated Dhaka as the seat of the proposed National Assembly outlined in the 1962 Constitution. The government appointed Louis Kahn and Muzharul Islam to design a capitol complex in Dhaka. During this “East Pakistan” Period the city started to expand itself toward north.

Growing political, cultural and economic rifts emerged between the two wings of the country. Dhaka appeared to be a center of revolutionary and political activity, as student activism and demands for autonomy increased. This lead to the political and constitutional crisis in 1971 followed by military operations from The Pakistani Army against the population of East Pakistan. Dhaka bore the brunt of the army’s atrocities, witnessing a genocide and a campaign of wide-scale repression, with the arrest, torture and murder of the city’s civilians, students, intelligentsia, political activists and religious minorities. Large parts of the city were burnt and destroyed, while much of the city’s population was either displaced or forced to flee to the countryside. Dhaka witnessed the surrender of the west Pakistan forces in front of the Bangladesh-India Allied Forces on 16 December 1971 and Bangladesh gained

Analysis

independence. Dhaka was declared the national capital by the Constituent Assembly of Bangladesh in 1972. During the post-independence period Dhaka witnessed rapid growth as Dhaka attracted migrant workers from across rural Bangladesh, 60% of population growth has been due to rural migration. Thus the city keep started again its expansion towards north. From the end of the 19th century Dhaka experienced improved economic growth and the emergence of affluent business districts and satellite towns,.Around the turn of the century the cityâ&#x20AC;&#x2122;s population doubled from 6 million to 12 million. Today Dhaka is one of the fastest growing megacities in the world and its population reached over 17 millions. This outstanding demographic growth has lead to a massive and mostly unplanned expansion of the city in each direction. This city sprawl is not expected to stop in the near future. In fact Dhaka population will reach over 30milions by 2025, so the city is expected to further expand.

provided a pleasant asset for livability and recreation. During the British Period a shift in this tendency started to appear: the city kept growing along the river bank but it started also to sprawl on the opposite side of the river towards north. In fact British introduced cars and railways and new settlements patterns based on these mode of transport spread. Consequently the river lost its fundamental role in the daily city life and Dhaka started to expand itself towards north, independently from the river, where free land was available. This trend started in the British Period but it is clearly observable in the East Pakistan and Post Independence periods and it is still present today. This process that lead to a change in the geographical direction of urban development, will be further investigate in the following paragraph.

It is important to notice that the city was born on the river and initially grow following the river bank. It is clear that during the Pre Mogul and Mogul periods the main direction for the expansion of the city was given by the river course. This is due to the fact the rivers had a prominent role in the life of the city. It constituted the main communication route to other cities and countries, offered resources and

Building Resilience through Green-blue infrastructures

Analysis

3.2.2 A changed relation between waterbodies and settlements Water is a peculiar element of the territory on which Dhaka lies. In fact being in a delta system whit a rainy monsoon climate the city lies on a humid territory, that was originally characterized by rivers and other water bodies, low lying soakable areas and a general flat orography with sporadic highgrounds. The inhabitant of the region dealt traditionally with water considering as a resource, being the main transport routes, and as a risk, because of floodings. They developed settlements pattern base on water considerations, that were therefore capable of withstand the most detrimental effect of water and at the same time of exploiting the opportunities that this resource offered. The first villages were built on the few natural highlands available buta traditional system of dig-elevate-dwell was developed, whereby ensuring water retention during floods and reservoir for lean period. The system

protecting the homesteads above flood levels with crop fields around was a time tested approach of the settlement pattern for sustainability in the area. (Mowla 2005 & 2009). The water bodies were the main transport corridors, streets being secondary to it. The rivers flowing through the flood plains, canals (locally known as khals), lakes and inland depressions provided a hierarchy and network of water bodies and navigation routes, with risen settlements alongside. There were flights of steps, locally known as ghats at intervals rising up to the lanes or community spaces. The ghats on the bigger water bodies or rivers were major community spaces where the daily activities took place such as bathing, washing or religious and commercial activities. Historic pattern reveal that the relationship of urbanization and water bodies was positive for the people and for the environment. In Dhaka traditionally the settlement structure evolved in consonance with water bodies. The city was crisscrossed by numerous

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water channels that drained the city as well as served as a main source of service and communication lines. Water bodies also offered highly valuable environmental and recreational asset for the area. With the British colonization, trains and cars were introduced, so roads and railways became prevalent and waterways started to loose their importance at an economical level and in the daily life of the city. Traditional urban patterns based on waterway started to be progressively replaced by wester models, developed in consonance with the new mechanical means of transportation. The existing water networks started to be destroyed: most of the water bodies and low-lying areas have been filled up and occupied by high-rise dwelling and roads. While the still existing ones are encroached by informal settlements and used as landfills. The city progressively dismantled its water-control infrastructure and consequently catastrophic and non-catastrophic floods have occurred since the late 1980s..

Overall historically Dhakaâ&#x20AC;&#x2122;s development responded well with the hydro-geological realities of the place. Traditional Architecture, Urban Design and planning in this region offered the best and integrated solutions towards human needs, in their relation with the nature, ecosystems and the community but contemporary development ignored living with nature. Due to the urban development pressure in Dhaka there is a tendency of filling of water bodies and flood plains resulting in the reduction of water retention capacity, diminishing public spaces and increasing water logging or flooding. Manmade drainage systems are not sufficient enough for this growing metropolis (Mowla 2013).

Analysis

3.2.3 Dhaka’s water bodies in Patrick Geddes view Sir Patrick Geddes (1854 – 1932) was a Scottish biologist, sociologist, geographer, philanthropist and pioneering town planner. He is known for his innovative thinking in the fields of urban planning and sociology. Geddes is famous for its “Conservative surgery” planning approach that seeks to consider “primary human needs” in every intervention. He worked with projects based on little but effective intervention to improve the urban quality of existing built environment, in opposition to the gridiron plan made as “heroic, all of a piece schemes” that were popular in the nineteenth and early twentieth centuries. Geddes has been a pioneer of civic survey, that he indicated as indispensable to urban planning: his motto was “diagnosis before treatment”. Such a survey should include, , the geology, the geography, the climate, the

economic life, and the social institutions of the city and region. His early work surveying the city of Edinburgh became a model for later surveys. In addiction he produce the first regional plan, that was intended to make clear the complex and interrelated relationships between humans and their environment.

create a “working system in India”, righting the wrongs of the past by making interventions in and plans for the urban fabric that were both considerate of local context and tradition and awake to the need for development. He revealed a particular sympathy with the religious and social practice of the region.

Geddes’ work in improving the slums of Edinburgh led to an invitation from Lord Pentland (then Governor of Madras) to travel to India to advise on emerging urban planning issues, in particular, how to mediate “between the need for public improvement and respect for existing social standards”. Geddes lectured and worked with Indian surveyors and traveled to Bombay and Bengal. Between 1915 and 1919 Geddes wrote a series of “exhaustive town planning reports” on at least eighteen Indian cities. Through these reports, Geddes was concerned to

Also Dhaka was included among the cities analyzed by Geddes. In fact its book Report on town planning Dacca was published in 1917 by the Bengal Secretariat Book Depot in Kolkata. He came to Dhaka after that the railway was already constructed along what at that time were the outskirts of the city. So the city had already started to turn its face towards land, and the river and canals had already begun to lose their economic importance and social status. Geddes was particularly keen on preserving Dhaka’s natural canal network,

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which he estimated to be about 25 miles in length. He argued that Dhaka’s commercial and industrial decline was linked to the decline of its internal water bodies. He also suggested that the canals could be a site for horticultural development, water parks and public amenities. In all the historical plans and recent survey that he re-elaborated both on a regional and urban scale he put particular attention in the representation of waterbodies. Its maps are therefore an accurate report of their presence in the city from the Mogul Period to its days. The planned development of Dhaka was remarkable. In particular for its attention in the conservation of water bodies and for the creation of big green public spaces that correspond to today Ramna Park and Suhrawardy Park.

Analysis

3.2.4 Disappearance of water from the urban landscape A comparison of historical pictures of the main buildings of the old city taken at the time of British colonization with the imag-

es of the same monuments taken in 2019, reveals that water as almost completely disappeared from the urban landscape. In all the historical images, the important buildings of the city appear to be on a water-

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front. All the important buildings such as Mosques, Palaces, Hospitals, Market and public buildings used to lay on the banks of the river or canals. In fact they needed to be easy reachable by people and goods and

as stated above the water network constituted the main communication lines in the city, with the system of streets being secondary to it. In addiction the presence of water gave to the building a positive envi-

Analysis

ronmental and recreational asset. For examples all the richest merchants of the city and the most eminent representative of the British rule, used to have their lavish houses on the river and canals banks, because it was

100

considered a prestigious and pleasant location. In all the photographs taken in 2019 water is not present at all. Except for the Hossaini Dalan which has preserved a water basin on its front, but it is no more connect-

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ed with any canal or other waterbody. All the buildings appear to have lost any relation to water. In general throughout all the city it is difficult to perceive this natural elements that on the contrary used to char-

acterize the urban landscape of Dhaka until the last century.

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3.2.5 Recent shrinkage of water bodies An analysis of the spatio-temporal change in waterbodies of Dhaka city, based on remote sensing and GIS revels a drastic shrinkage of them in the last fourty year. The study conducted by professor Ms Mahmud and published on the Journal of Water Re-

source and Protection in November 2011, analyze two categories: the first is made up by rivers, lake and other permanent waterbodies while the second correspond to the low lying soakable area, which contain water only during the wet season and not during the dry season. The data have been studied each 10 year giving respec-

Example of land grabbing and destruction of waterbodies in Dhaka: Rupnagar Lake 2006-2016

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tively an image of the waterbodies in the city in 1978, 1988, 1998 and 2008. Comparing the 4 images, it is clear how massive has been the phenomenon of filling low-lying areas and waterbodies to buil new streets and high-rise dwelling. In fact the city has almost completely lost its water bodies except for the rivers sorrounding the city and

some lowlying areas in the fringes of the city that have not been urbanized yet. Most of the canals and lake within the city have been lost. The study notes that about 52 percent of the lowlands and 33 percent of the water bodies, rivers, lakes, etc. in Dhaka have been lost to urbanization.

(from â&#x20AC;&#x153;The sorry state of Dhaka city canalsâ&#x20AC;?, 2017, www.dhakatribune.com)

Analysis

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3.3 Waterlogging: greatest threat for the city

As already mentioned in the previous paragraphs Dhaka has been experiencing a gradual increase in water-logging over the last decade. Moderate to heavy rain causes serious drainage problems in many parts of the city with knee-deep water on the streets. In fact stormwater get stagnant and streets and other open spaces get flooded because the amount of stormwater that the city receive as rain is bigger than the capacity of its drainage system. Dhaka is known as a water logging and drainage congestion cityâ&#x20AC;&#x201C; losing its past glory for numerous natural khals and wetlands of fresh water. The surface water area of Dhaka Central Region is about 13% of total land area. 3.3.1 Embankment: from floods to waterlogging After the almost complete destruction of the water-bodies that served as water control infrastructure, Dhaka started to experience severe floodings. Three floods in the recent past, in 1988, 1998 and 2004 were catastrophic. In 1988, 85% of the city area was submerged with a water depth of 0.3m to 4.5 m from the ground level and inundation continuous for 20 days. 60% of the city habitant was affected. The 1998 flood was due to heavy rain and spring tide, during this even 56% of the city area were submerged and inundated continuously for 2 months. During the 2004 flood that was caused by heavy rain and spring tide, flooding was

continuous for 2 months. Commerce and industry area of the northeast Dhaka city was damaged for inundation. After the devastating flood of 1988, an extensive study in the name of Flood Action Plan (FAP) was launched. The FAP had several components, of which Dhaka Integrated Flood Protection Project (DIFPP), namely FAP 8, was designed to look into the cause of and remedial measures against flooding of the capital. Under this plan, an embankment all around the western part of the city was built to protect the city from overflowing water from rivers. Pumpstations were added to the embankment to drain out stormwater from the city the to the rivers. After the first implementation, improvements of the western area against both flood protection and landslide were nearly completed by 2009. Before the construction surface water by rainfall used to drain to the river by natural gravity drainage when the river water level was low. And the city area used to be inundated when the river is flooding because of non existence of flood protection measures between city and the river. With the completion of the embankment around the city, Dhaka west started to be protected from floodings from the rivers but this infrastructure generates drainage problems during rainy periods. In fact surface water drains into the river thorough regulator structures along the dyke when the river water level is

Analysis

105

low. Surface water is drained into the river by pumping drainage when the river water level is high. However, as capacity of the pumping drainage is insufficient to drain waterlogging takes place, city area is inundated by rainfall not for flooding by the river. The situation is usually dramatic because during the monsoon season the huge amount of runoff generated by continuous rainfall coincides with high water level in the river systems. When water level in the rivers remains higher than the terrain inside the city area the city drainage depends very much on the pump stationsâ&#x20AC;&#x2122; capacity, that has been proved to be insufficient. The embankment is built as a raised road encircling the city on a earthen slope which is around 4 meters higher. Pump stations have been built on the intersection between the major canals of the city and the rivers, where the canals come across the embankment. Today during moderate to heavy rain events, most of the southern part of Dhaka gets waterlogged. Daily activities in these parts of the city are nearly paralyzed and heavy traffic jams occurs due to stagnant water on the streets. Normal traffic movement is hampered buring rainfall over 25mm, creating traffic jams that make people waste their time. In some areas that are considered as affected by severe waterlogging, the water depth becomes as high as 50 to 70cm. The city drainage system as the capacity to drain out 10 to 15 mm of rain water per

106

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Enbankment

Pumpstation Analysis

107

hour, while the rain intensity can reach up to 105mm per hour. Waterlogging has deteriorated to the point that a mere hour of rain is enough to flood a considerable part of the city. Roads in various places including Mirpur Kazipara, Shewrapara. Torahimpur, Azimpur, Kalabagan Matuail Jatrabari Jurain Denira, ShanirAkhra, Dania, Shyampur Motifheel. Rampura Dhanmondi, Karwan Bazar, and Sher-e-Bangla Nagar get crlogged during any small storm or medium rain fall. Trafc in these areas get stalled for hours, causing immense inconvenience to commuters. The encroachment on Katasur canal causes waterlogging in Rayerbazar and Mohammadpur areas. Filling up Ramchandrapur canal is responsible for waterlogging in Islambagh, Nawabgonj and Hazaribagh. A more than 30 meter wide open canal in the Southern part of Dhaka, Dholaikhal,was filled up and a 2.5 meter by 2.5 meter box culvert was installed in its place. Narrowing the canal has led to waterlogging in BUET, 41 Bakhsibazar, Hosnidalan, Nimtali, Nazimuddin Road, Bangshal, Aga Sadek Road, Gandaria, Postogola and raridabad areas. Encroachment on Segunbagichakhal Waterlogging in Shantinagar, Inner Circular and Middle Circular &oads Arambagh Fakirapul, Gulisthan Zero Point Motijheel, Dilkusha and Saidabad areas. Shrinking of the Jiranikhal and choking shrinking of the Jiranikhal and choking up of the Shajahanpurkhal are responsible for waterlogging in Malibagh. Mouchak and Shantibagh areas.

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Infringement on Shahjadpurkhal at Maniknagar and Manda causes waterlogging in Shantinagar, Inner Circular and Middle Circular Roads Arambagh, Fakirapul, Gulisthan Zero Point Motiihee Dilkusha and Saidabad areas. Shrinking of the Jiranikhal and choking shrinking of the Jiranikhal and choking up of the Shajahanpurkhal are responsible for waterlogging in Malibagh, Mouchak and Shantibagh areas. Infringement on Shahjadpurkhal. prevents flushing out of rainwater and waste water from Kuril Pragati Sarani and adjacent Begunbari khal has resulted in waterlogging in Tejgaon, Gulshan 1 and Mo-

hakhali areas. Encroachment on Mohakhali khal is causing waterlogging in Nakhalpara, Arjatpara, Shahinbagh The Kalyanpur pump regulating pond of the water supply agency has been filled up, causing waterlogging in Taltala Agargaon, Kazipara, Shewrapara, Barabagh, Mirpur Section and adjacent areas. Encroachment on up of Diabarikhal by the developers are responsible for creating waterlogging in Uttara and Banani Rasulbagh and Ibrahimpurkhal and fillingu up of DiabariKahl by the developers is responsible for creating waterlogging in Uttara and Banani (Salam et al. 2018)..

Waterlogging (www. lessdifficultdhaka.com)

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3.3.2 Causes of waterlogging The source of the waterlogging problem is, as previously stated, the encircling embankment. But this flood protection infrastructure alone would not cause a so serious urban issue. In fact some phenomena and condition reveal to be concurrent causes of waterlogging. Improper solid waste management Dhaka city produces an average of 3500 tons of waste every day. Due to the limitation of resources and proper waste management system, around 400 tons of it remains on the road surface and in drains, Rainwater washes away the wastes and creates gridlock situation in the inlets of surface drains. Small drainage sections in inlets and outlets without appropriate lining of slopes in storm sewer network make the drainage system really easy to get obstructed by solid waste. Both in pipes and canals solid waste reduce considerably the capacity of drainage. Unplanned development Ever increasing population has led to unplanned urban land development and unauthorized land filling that results the disappearance of natural drainage pattern. It is a common scene along the Dhaka city urban periphery. This phenomenon interrupts the drainage network and reduces detention basins which have aggravated the waterlogging problem. About 18.72 km2 of rivers an canals, and about 76.67 km2 of wetland went lost from 1978 to 2009. That

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means, about 60% of existing wetlands and about 65% of rivers and canals are lost during this time in Dhaka Metropolitan Area (DMA). In addiction unplanned development and encroachment are making Dhaka a concrete jungle with very little green space and soil. As a consequence, rainwater remains on the surface and takes a long time to penetrate into the ground Destruction of natural drainage system Dhaka had a natural drainage system consisting of canals, ponds, lakes and reservoirs. Unplanned development and encroachment of natural water bodies make also the remaining canals and ponds to quickly transform into black and smelly waters. To improve the environmental and traffic condition, many of these canals were transformed into box culverts and connected to underground drainage network during 1990s. Main highways were also built upon them. According to Dhaka Water And Sewerage Authority, out of 43 canals in Dhaka, 17 have completely disappeared and the remaining 26 are in bad condition. Eight disappeared canals have been revived by box culverts. Unplanned land filling and development had made the rest of canals unseen. Limited capacity of drainage system and pumpstations The drainage system of Dhaka city has clearly proved to be ineffective. Itâ&#x20AC;&#x2122;s reduce capacity, especially in comparison with the

Building Resilience through Green-blue infrastructures

outstanding needs of the city are due to different causes. The drainage network is not properly widespread and some areas are poorly serviced. The system mix storm water and sewerage, causing not only inefficiency but also problems to treat such big amount of water to maintain a decent water quality. The small section of pipes, inlets and outlets gave to the system a scarce capacity and furthermore make it particularly prone to obstruction by solid waste. In relation to this the system lack a proper and continuous cleaning and maintenance, which is particularly difficult to implement because the drainage system is run by different organizations and not controlled by only one agency. This organizational structure lead to a system which is really difficult to be organized, managed and coordinated. Flat orography Due to the topographic condition, under gravitational force the rainwater cannot discharge to the lakes, canals, retention areas and surrounding rivers smoothly and remains stagnant in low lying areas. Moreover, people have a tendency to develop comparatively in higher ground through raising the ground level. This keeps the existing road networks in lower level which receive the rain water from the surrounding areas.

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3.3.3 Consequences of waterlogging The inundation of the city by rainwater results in inconvenience to the inhabitant. Impacts of waterlogging range from interruption of day-to-day life to the extent of severe damage to resources. Life quality hazards Paralyzed traffic Rapid urbanization causes unbearable traffic congestion in Dhaka even in the dry season. The situation becomes worst when it rains over 25 mm. The victims of this phenomenon are pedestrian users but also people with cars. The sufferings include risk of falling down in open drain and manhole, malfunctioning of the motorized vehicles, raised fare of the transports etc Disrupted of daily activities In such situation people try to avoid movement without emergency situation. So they are practically obliged to stay at home, avoiding any personal, professional or leisure activity. Closed schools. Because of the unbearable traffic condition and the actual danger of moving around the city during waterlogging, school must be shut down, until the rainy days are not over. WATERBORNE DISEASE In addiction to this obstacle to daily activi-

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ties, waterlogging lead to even more serious and dangerous problem such as the contamination of water bodies and the transmission of water borne diseases. Strom water is often contaminated by mixing with the wastes from hospitals, industries and overflowing latrines as well as garbage in the streets and drains. This polluted storm water runoff contaminates ground water and the receiving water bodies, like the canals, rivers and detention areas. This stagnant polluted water results in inconvenience, odor, breeding sites for disease vectors, water borne diseases, skin diseases and therefore triggers health hazards and miseries. Economical Losses Loss of potential income The deleterious effects of waterlogging include direct financial costs, loss of income potential in various ways. During the waterlogging disaster commercial activities nearly come to a standstill in Dhaka. Shopping malls, restaurants even the banks have least customers and witness unusually low transaction. As a result, production reduces, delay of shipment occurred price of raw material increase. As contaminated storm water overflows to water bodies, it causes a mass death of fishes which turns into huge loss for the owners DAMAGE TO STRUCTURE AND INFRASTRUCTURE Prolonged waterlogging and water infiltration decreases the longevity of the floor and

Building Resilience through Green-blue infrastructures

walls, brick foundations and substructures of the buildings in low lying areas. It also causes the problem of subsidence, dampness and other damage of infrastructure and impairs underground utility services, such as water, gas, sewerage and pipelines Moreover, roads are damaged which lead to movement problem even after the water has subsided. In addiction damage of infrastructure, such as road, service utilities not only hamper the regular life of citizen, but also demand an enormous amount of source for the replacement and maintenance of the damaged amenities. Owner of the households faces huge financial losses due to the damage of substructure, brick foundations, kanchha (temporary or semi permanent) houses during the waterlogging.

ly depends on the weather condition since people avoid moving in knee-deep water level without emergency. They live in shacks that get flooded and damaged during waterlogging periods. Their clean water sources are usually precarious and easily get contaminated by stormwater with the spreading of water borne diseases.

Environmental problems Prolonged stagnant water and continuous release of wastewater causes harm to the habitat of flora and faunas. Contaminated storm water imbalances the ecology of the habitat by polluting the soil and water bodies. This causes depletion in the quantities of trees, aquatic plants and animals. Low income groups: most vulnerable to waterlogging Poor people are the worst sufferers as inundated roads directly disrupt livelihood of the poor people. The income of rickshaw pullers, street vendors and daily labor great-

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3.3.4 The drainage system The sewer system of Dhaka was originally designed as a separated sewer system. Meaning that is was planned to be composed by two parallel sewer systems: a sanitary sewer, collecting domestic, industrial and commercial wastewater (that need to be led to a treatment plant) and a storm sewer, collecting stormwater. But eventually the system turned to be a combined sewer due to illegal connection of sanitary waste waters into the storm sewer. So today sanitary wastewater and stormwater are collected in the same pipes. The drainage system of Dhaka is divided in secondary drains, that collect stormwater from the streets and sanitary- and storm-water from the buildings, and primary drain which receive water from the secondary drains and conduct it to pumpstations, and consequently to rivers.

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There are 6 river pumpstations on the embankment, which let water overpass it and reach the rivers. During riversâ&#x20AC;&#x2122; high water levels in the monsoon season, they pump the water from the drainage system, up to the rivers. Their pumping capacity varies from 9.6m3/s to 22m3/s . In addiction there are 65 small network pumps disseminated in the city, that pump water from low-lying areas to higher ducts. The secondary drain can be small open drain or under-sidewalks pipes. Open drains at the sides of the road, receive directly stormwater from the street and sanitary and stormwater from the buildings in conducted to them. There is almost 1milion kilometers of open drains in the city but this type is mostly diffused in the oldest part of the city and in the underdeveloped areas, Under-sidewalks pipes constitute the

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most moder type of secondary drains in the city. It has been calculated that under-sidewalks pipes run through the city for more than 1 millions kilometers. They have inlets for stormwater from the street, and they also receive stormwater and sanitary water from the buildings. There are different types of primary drains 22 open canals are present with a width of 10 to 30m and a total length of 65km. It has been estimated that these infrastructures drains more than 80% of stormwater of Dhaka. The most widespread primary drains are the more than 300km of underground concrete pipes having a diameter ranging between 1 and 3meters. Box culverts and brickmansory drains have been introduced in the drainage system of the city to replace some of the open canals. This substitution let the surface free for new

urban high-ways and building but also significantly reduce the capacity of these sewer lines. 10km of Box culverts are accounted today in Dhaka with dimensions ranging between 2.5m by 3.4m to 6m by 4.1m. The current drainage system of Dhaka is able to carry only 35 to 40 percent of stormwater to the pumping station in a reasonable period of time. In addiction pumping can not be made continuously due to electricity failures and mechanicals faults. Waterlogging management with this drainage system based on pumping has revealed to be costly, energy demanding and unreliable due to sudden mechanical and power failures.

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3.3.5 Organizations and plans A major obstacle in the waterlogging management is given by the fact that there is not only a single organization in charge for the problem. A lot of different organization both on a government and local level are responsible for storm-water management and the consequent problem of waterlogging. At a government level, four Ministries of the Peopleâ&#x20AC;&#x2122;s Republic of Bangladesh are intimately associated to waterlogging: Water Resources, Land, Disaster Management & Relief, Environment and Forest. Examining their plans and acts resulted general inadequacies and failures in their policies and strategies to tackle the problem.

drives against canal grabbers. Rajdhani Unnayan Katripakha RAJUK (Capital Development Corporation) maintenance the rehabilitated water bodies (Hatirjheel, Gulshan, Banani, Baridhara and Dhanmondi lakes). Dhaka South City Corporation maintains 466km open and 495km covered drains. Dhaka North City Corporation runs over 1200km of drains. The Bangladesh Water Development Board has constructed and runs two pumpstations. Bangladesh Inland Water Transport Authority and Dhaka District Administration conduct drives against canal grabbers in cooperation with DWASA.

On a national level important measures have been adopted to address the environmental issues of coastal area, so that significant steps towards coastal resilience has been made. But on the urban field, environmental problems have not been properly addressed and the country policies are not creating resilient cities. As the other issues, also waterlogging remain unsolved by government policies.

There is an evident lack of coordination among these authorities, they do not share common plans and do not have conference to tackle the situation together.

On a local level over 50 organizations are involved in the stormwater management and therefore responsible for waterlogging. Among these 7 authorities can be identified as the main ones. Dhaka Water and Sewerage is responsible for the maintenance of 10km box culverts, 65km canals, 346km drains, 4 pump stations and it conducts

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There are different plans, urban regulatory codes and other planning tools that are involved with water logging, but none of them have yet solved the problem or seem to be capable of moving effective steps towards the solution of waterlogging. In particular Stormwater Drainage Masterplan for Dhaka City by Dhaka Water And Sewerage Authority (DWASA) is focused on building new infrastructures in the suburbs, to avoid that the same problem of waterlogging will be produce in the new development sectors. For the core part of the city it is most focused on cov-

Building Resilience through Green-blue infrastructures

ered drains. These two are surely important aspects but the plan lacks further actions to protect and enhance the existing canals and waterbodies. Anyway it is important to remark that DWASA had conducted some important intervention for the preservation of some of the canal, but these have not been extensive. The Dhaka Structure Plan 2016-2035 by RAJUK highlight waterlogging and need for preservation of water bodies but does not provide any structural action for water management and for rehabilitation of

waterbodies. In addiction the building construction rules, or building code or any planning regulation nor wetland act calls for integrating natural water bodies or channels into the urban planning and design frame work.

Waterlogging (www.dhakatribune.com)

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3.3.6 Effects of climate change The already alarming situation of stormwater management and the problem of waterlogging will be further exacerbated by the effect of Climate change. Climate science predicts that extreme rainfall events will become more frequent overtime. Thus, Dhaka may experience a number of intense rainfall events between now and 2050, meaning that the return-period of the September 2004 baseline event (341 mm per day) may be less than 100 years in the future. The effects of climate change in the South Asia region, including greater rainfall intensity and increased frequency of extreme weather events, are expected to aggravate Dhaka’s vulnerability. The Intergovernmental Panel on Climate Change (IPCC) predicts that South Asia will experience an increase in both average and extreme rainfall during summer monsoon seasons of longer duration. It is expected that extreme rainfall events in Greater Dhaka could increase by 16 percent by 2050. In the rivers around Dhaka, monsoon-season water levels may increase by about 30 cm. Traditionally, in Dhaka region, the rainy season starts in mid-June and continues for two months, but now it is getting shorter but more intense. The change throws Dhaka’s drainage system ineffective, while the wetlands that form the essential part of the drainage system are being gradually reduced. Uncertainty analyses conducted by the Institute of Water Management on the mag-

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nitude and timing of climate change risk highlight the need to make required investments in structural measures that adapt the drainage system to more frequent extreme rainfall events. One study (BCAS)indicates increase in maximum and minimum temperatures in Dhaka city, leading to hotter summers and cooler winters. In the last 100 years the average temperature in Dhaka has increased by 0.50 degrees Celsius, and in the next 50 years it is expected to increase by another 1.5 or 2 degrees. The study also reveals that the average temperature in the metropolitan area is 2 degrees Celsius hotter than in the peri-urban zones surrounding it, the existence of ‘’heat island’ effect’ in Dhaka city. In this context, the expected loss of urban open space and the densification of builtzones will make the city retain more heat. Asa result, Dhaka will gradually get hotter every year. The changing climate will affect the city both through the consequences of the increase of average rainfall and temperature but also from extreme weather events linked to these changes. The average rainfall increase will lead to increase risk of flooding, increase risk of water logging and increase risk of immigration due to river bank erosion. The average increase in temperature will produce an increased energy demand for cooling, will further degrade air quality and

Building Resilience through Green-blue infrastructures

will create a scarcity of clean water during dry periods. Extreme waterlogging events will damage households in slum and squatter areas, roads and other infrastructures, utility services and spread out of water borne diseases. Extreme drought will cause severe ground water scarcity, while heat or cold

waves will produce short term changes in energy demand and health stress due to extra heat or cold. Furthermore, climate change has compounded problems of environmental degradation and has led to deterioration of ecosystems, adding yet another dimension to poverty.

Vulnerability to climate change (www.ejfoundation.org/reports/climate-displacement-in-bangladesh)

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3.4 DHAKA'S WATERBODIES

The metropolis is surrounded by a circular system of rivers and has lakes, ponds, canals (locally known as khals), and low-lying areas within this riversâ&#x20AC;&#x2122; system. In fact the surface water area of Dhaka Central Region is about 13% of total land area. The low-lying areas, canals, lakes and ponds act as retention basins and perform the drainage function. The storm water is accumulated in the low-lying areas and lakes; flows through the storm channel i.e khals and discharged to the surrounding rivers. The functioning of the drainage system depends on the water level of surrounding rivers. Generally, during monsoon the surrounding river water remains high. Thus, water cannot be naturally discharged and need to pumped out at the pumpstations, which, as already stated previously, have an insufficient capacity. The Dhaka Region used to have more than 50 khals that drain 80% storm water of the city to the surrounding rivers. But the illegal encroachment, lands grabbing and filling, the indiscriminate dumping of domestic and industrial waste into rivers and canals are gradually destroying this system of waterbodies and accelerating the drainage congestion. Concerns over the shrinking drainage canals have been acted upon before. In 2008, Dhaka Wasa took initiatives to reclaim the 26 canals from illegal occupation by building walkways and channels and by planting trees along the canal embankments. A Wasa official told the Dhaka Tribune that

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the project was not implemented properly: â&#x20AC;&#x153;A Wasa report published in 2010 shows that the vanished canals were filled up and grabbed by 10,500 grabbers with political power,â&#x20AC;? he said. This section aims to investigate the condition of the existing waterbodies within the embankment, to clearly identify which are more endangered and which on the opposite are in a good status. The paragraphs will further examine by which issues the waterbodies are affected and by which reasons their are caused. On the other hand also waterbodies in good conditions will be studied to explore which positive characteristics they have and why they are well preserved, so that this could help the strategy and design process. In this study the waterbodies have been categorized in three different typologies because of their status and processes that they have undergone to reach their current condition: renovated urban waterbodies, suburban area waterbodies, undeveloped urban canals. Renovated urban waterbodies are located in the most central neighborhoods of Dhaka in the souther part and at the eastern edge of the central area of the city. Suburban area waterbodies are mostly present in the northern part of central Dhaka that has been developed more recently. In particular they are located at the western side of the new Hazrat Shahjalal Internation-

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al Airport. The undeveloped urban canals are located in the most densely residential districts of the city in the south-western part of the city. In addiction canals that have disappeared and those who have been substituted by box culverts can be seen on the map. 3.4.1 FADING OF CANALS IN DHAKA In the past the City was regarded as the Venice of the East or the City of Channels. In fact historical references from the Mogul Period indicate that the area currently covered by central Dhaka was criss-crossed by a widespread network of canals. Even some decades ago, there were numerous lowlands, canals and channels within and around Dhaka that used to drain the City efficiently, in fact a survey conducted in 1960 reveals that at the time 65 canals were present within the city. Then urbanization started to occur very fast and with larger magnitude in Dhaka. This has caused extensive urban area expansion and as a result canals, wetland and other water bodies started to be shrunk by the new buildings and roads and are now quickly vanishing from the urban landscape. In fact in 2002 the number of existing canals was only 43 and with the further urban growth of the last century it has dropped at 26 in 2019.

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3.4.2 Renovated urban water bodies Renovated urban waterbodies are lakes and canals that have undergone urban and landscaping planning during the recent development of the city. They are surrounded by parks, equipped with public space facilities, such as benches, food stalls, toilets sport and entertainment areas. They are crucial spaces in the daily life of Dhaka citizens, they are visited frequently by different social groups and/or for different purposes at all times of the day. In addiction they get really crowded at weekends during the dry season. There young couples enjoy the sunset , families take their children for leisure, adults run and exercise after work, elderlies go for a walk in the early morning and the youngsters simply gather. They are located in the most wealthy neighborhoods of the city, in fact they are clean and well maintained. They have pedestrian footpath along their banks and some of them have public transportation lines of water buses. They also play a fundamental role in the environmental asset of the city. In fact these waterbodies are important tools in the water management system of the metropo-

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Hatirjheel

lis. They collect stormwater during heavy rainfall and store it until the level in the surrounding rivers gets lower, so that water can naturally be discharged outside of the city. without overloading the pumpstations. The water and vegetation are

less thermally absorbent than artificial material, so they keep the temperature lower while trees also improve air-quality, resulting in a mitigation of the urban heat island effect and reduction of the detrimental effects of the heat waves.

Analysis

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Ramna Park

Dhanmondi Lake

Hatirjheel

Dhanmondi Lake Analysis

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3.4.3 suburban area water bodies Suburban area canals are located in the outskirts of the city, that have been built recently. The urban planning of this new settlements, took place when the concerns related to waterlogging were already existing and a more water-sensitive design has been implemented. These canals have therefore been planned together with the new streets and buildings in an integrated manner. Consequently they appear to have big cross-sections (and consequently a considerable capacity) and defined banks with significant empty space. They have footpaths and sometimes small cafes and food stalls along their course. Only in some areas they are equipped with public space facilities. In addiction some of them lack trees and vegetation that would make them more pleasant for the visitors and more useful for the city for the mitigation of the Urban Heat Island Effect, the improvements of the air quality and the support of biodiversity. They are not visited as frequently as the most central ones, but offer a suitable option for a getaway from the hectic center. They are not used as waterlines for

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Diabari Canal

public transport, although their remarkable cross section would easily allow navigation. Some of theme have problems related to water plants, that in some point are so dense that they obstacle the

regular flow of the water. As it is also obstacled in some points due to the exploitation of the canal for piscicolture, often difficult to be stopped because it is by influent people of the area.

Analysis

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Uttara Lake

Pocka Lake

Uttara Lake

Pocka Lake Analysis

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3.4.4 undeveloped urban canals Undeveloped urban canals are located in the mostly dense neighborhoods and have been victims of the unplanned and rapid urban growth of the city. Thus they have been shrunk by the buildings, appearing today narrow and with no or little empty space on their banks. Their existence and dimensions are endangered by land grabbers who pour sand into them to create new land for buildings and by roads and box culverts that obstacle their flow. They are in poor condition due to littering, informal settlements and water plants. The water is therefore stagnant, polluted. and emits fool odors. Their banks are often not accessible and result into a neglected space that is subject to no cleaning and maintenance and is not equipped with public space facilities and greenery. Some of these urban canal, like Kallyanpur Main Canal still have a remarkable section and consistent space on their banks, even if their condition are poor and they are crossed only by few roads through big bridges . Some other like Ramchandrapur are remarkably shrunk by the dense urban fabric, having buildings

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Diabari Canal

on their banks and being crossed by numerous roads but they have a significant and constant cross-section. Few other, like branches of Kallyanpur canal have a restricted section that is

often interrupted by boxculverts. Most of them could likely disappear in the next future, as it has already happened to many other canals around the city, despite their fundamental drain function.

Analysis

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Kallyanpur main canal

Ramchandrapur Canal

Kallyanpur branch canal Analysis

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3.5 Public and green space

3.5.1 TYPOLOGIES AND USES OF PUBLIC SPACE Public and green space can be defined as un-built lands within the city which provides environmental, social and economic benefits for the communities that cover land and water bodies devoted to recreation, scenic beauty, conservation. In addition to their ecological and aesthetic value to urban dwellers, open spaces are used as recreational facilities either in active or in passive mode. Apart from open space, urban heritage also form an integral part of recreation for domestic and foreign tourists. During the British period, Dhaka experienced an expansion to the north, while the peripheral green areas were incorporated within the city limits. A green core remained open in the city center. Thus, in 1825, a green belt was developed by freeing water from Lake Ramna and from a huge plantation in the surrounding areas. Ramna Park was founded in that area in 1908. A racecourse was established in a vast open space near Ramna. This area became Sohrawardy

Uddayan in 1972 with a huge plantation. Also, there was a large lake, called Motijheel, towards the eastern end of the city. Then new areas of Dhaka like Paltan, Ramna, Shantinagar, Malibagh, Kakrile, Tejgaon had thousands of trees. Also in the west, Azimpur, Fulbaria, Bakshibazar and the University of Dhaka were very green and open. Likewise, several ponds and Khals were scattered all over Dhaka. During the 1970s, the vegetation of historic Dhaka was interrupted and the water bodies were filled. At the moment there are no trees in the center of the green shelter. These two green areas, which act like the thrusts of the city, are also being swallowed up by the different buildings and government projects. â&#x20AC;&#x153;The inter-linked central parks of Dhaka and the nearby Stadium Complex become increasingly precious legacies with each passing year. Sadly, with Dhakaâ&#x20AC;&#x2122;s rapidly growing population, unless they can be replicated, their value will be diminished by Analysis

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over-utilization and these valuable assets permanently impoverishedâ&#x20AC;? (Dhaka Structure Plan, 1995). In a dense and congested city like Dhaka, the inhabitants try to make the most of every square meter of available space, making the public space a multi-layered and multidimensional entity. Public space is almost always described as an inclusive space, open to all, formed by a network of streets, parks and squares. In Dhaka, due to the lack of private space, public space becomes an external extension of living and working spaces. The boundaries between public and private places become confused because of the way they are used. Public space becomes a necessary good for survival, a channel of flows and a place for recreation and social integration. The public spaces of the city of Dhaka are therefore characterized by their diversity and intensity of uses.

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STREETS For the poorest people of Dhaka, a public space such as the street is an emblematic element of daily life: it is a place of sustenance, one of the few resources available for most of the population. Public space is used as an extension of private space or as a place to trade, organize public or private events, play sports or meet friends, along with many other uses. Bargaining with sellers, eating at a high table on the street, replacing car tires and sipping a cup of tea at a stall are just some of the activities that can be done on the sidewalks of Dhaka city. This reflects the local street culture of the city, where the street is the stage on which the choreographies of daily daily activities form a comfortable rhythm that manifests the collective identity of the cityâ&#x20AC;&#x2122;s public. However, this local street culture is increasingly threatened by the influence of

globalization. Wide and wide streets with cars running are replacing the humanly resized and crowded streets that are emblematic of the local culture. Informal businesses in Dhaka are a huge part of the cityâ&#x20AC;&#x2122;s economy as around 5,000,000 street vendors work in public spaces. Most street vendors work on sidewalks, road junctions or even parks or fairs at any time of the day. They provide an essential service to all socio-economic segments of the population by offering low-cost goods and services in convenient locations. The lack of private and public interior spaces implies an important need for places to meet and organize events. The inhabitants have appropriated public spaces for private events, building bamboo installations to shade and privatize entire streets for private use. Roads therefore become an external extension of private space, a place for social interactions.

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Dhaka is considered one of the least livable cities, but some parts of the city can be more enjoyable than others. Some streets of Dhaka are very colorful, their walls taken by street art. This kind of art is a way for the inhabitants of the neighborhood to reclaim public space and to appropriate the place. Public space in Dhaka is a multidimensional entity: a space for appropriation, socialization, exchange and a subsistence good for the poor. All these uses of space show how the inhabitants of a megalopolis can be resilient and creative.

PARKS Parks are probably the most used and best-known open spaces in the urban environment. It has been found that middle income people, come here from distant places bearing the communication cost only to get relief from the exhaustion of busy urban life and therefore parks should be provided both at a community level and at an urban level. Within urbanized areas, parks are used purely for recreational purposes. They are of two categories mainly: city level parks (from 20-32 hectares) for all citizen and local parks (usually less than 0,4 hectares) for neighborhood people mainly. There are numerous activities that citizens do in parks, such as having a picnic, taking their children to play outdoors or go on a romantic date with their partner. Parks always host many people, especially on Fridays and Saturdays. In addition to the

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citizens who use the parks for recreational purposes, there are those who attend them to get physical benefits, by walking or doing exercises. The parks are also full of street vendors who use the space as a work space and therefore a source of income. At present, Dhaka city has 54 registered parks under Dhaka City Corporation as opposed to Dhaka structure planâ&#x20AC;&#x2122;s suggestion that, open space should be at least 20% of total city area. According to the planning standard, Community Parks should be provided within 1,6 km of all homes. Moreover, the existing parks are in need of maintenance and control. There is dirt and garbage everywhere in the large parks and no proper system or infrastructure in place. So, a system of proper maintenance is necessary to make sure that these open public spaces are kept clean, hygienic and environmentfriendly.

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MARKETS Markets in Dhaka are mostly open places in the city where negotiations take place for the sale or purchase of certain products. They can be placed in a street or in an open space that, every day of the week, become a commercial space characterized by a very high fruition in which citizens, in addition to buying and selling products, interact and “live” an urban space that otherwise would be perceived collectively in a different way. There are numerous types of market in the city of Dhaka, from the fruit and vegetable market specialized in “western” fruits to the fabric market, from the fish market to the imitation jewelery market. With the recent spread of consumerist culture in this part of the world, even markets that do not sell basic necessities are extremely frequented and experienced by the citizens of Dhaka.

small number of stalls or carts at the corner of the streets, or they are placed inside huge galleries. Unfortunately the majority of these spaces is are not protected by regular maintenance, ending up becoming places that are often neglected and with a poor level of cleanliness. The peculiarity of this way of selling and buying goods lies in the relationship that is established with the urban context in which the market is located, becoming an element able to characterize and distinguish, not always positively, specific neighborhoods and parts of the city. Precisely because of this ability to animate but above all to characterize urban space, the market should today be considered a strategic element for the promotion of urban and commercial policies for the city, capable of supporting processes of social and economic recovery of some particular contexts urban.

Markets are often located in open spaces, in a spontaneous context, consisting of a

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PLAYGROUNDS AND SPORTS FACILITIES These are open spaces are assigned for more or less organized out-door sports facilities both at metropolitan level (like stadiums, swimming pools and tennis complex at metropolitan scale), and at community level (like play fields in residential areas, usually 2-9 acres). Besides, the ‘Urban

Recreational Areas’, like small and medium sized parks and playgrounds, are frequently used by the local children and youth. With the unplanned urbanization taking place inside the city of Dhaka, most of the playgrounds of the main neighborhoods have been seized by influential political groups. There is also no specific policy in the country to improve the game and sports and the lack of open space and playgrounds is the main obstacle for which children cannot enjoy the right to play in Dhaka.

The detailed Area Plan for the Dhaka Metropolitan Development Plan (DAP 2010) does not present any reference regarding the minimum quantity or quality guidelines for playgrounds with reference, for example, to the number of people, density or geographical boundaries. In the “Dhaka South City Corporation” only 9 playgrounds were organized, while in the “Dhaka North City Corporation” has started a redevelopment project of 26 parks and playgrounds under its jurisdiction to make recreation centers more suitable for public use. The project aims to give children more opportunities for playing and doing safer sports for their development and protection, and the public and private sector will have priority and will invest more to create spaces for playgrounds and sports facilities for children.

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SHOPPING MALLS Shopping centers play a rather important role in the social interactions of the uppermiddle class of the city of Dhaka. In addition to hosting shops of various kinds, they also have commercial activities in the buildings that encourage socialization, particularly among the young: restaurants, bars and multiplexes are just some of the activities offered by these spaces. If an analysis of the architectural system of the shopping center is carried out, the social space is the element that performs the function of connecting all the elements of the shopping center. The structural elements of the shopping center can also be compared to the structural elements of the city, reproduced on a smaller scale: there are equivalents of streets, squares and enclosed spaces. The construction of the urban network takes place as a result of fixing the basic

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nodes of human activity. Depending on the activity of the nodes and the distance between them, the connection hierarchy is formed. The movement in the space of the shopping center occurs in a similar way. Inside the anchors of the shopping center structure the function of magnet for visitors is performed. The anchors are connected to the social space along which the other tenants are located. Depending on the degree of attractiveness of the anchor and its position within the structure of the shopping center, the distribution of human activity in the social space of the shopping center is verified. With the culture of consumerism, an approach to the western lifestyle and an improvement in the economic situation of the average social class, these spaces have begun to cover an increasingly fundamental connotation of the life of the citizens of Dhaka, despite the lack of inclusiveness.

Building Resilience through Green-blue infrastructures

PLACES OF WORSHIP With 90% of the population of Islamic religion and minor percentages of inhabitants with Hindu, Christian and Buddhist faith, Dhaka hosts a vast multitude of places of worship. These include countless mosques, Hindu and Buddhist temples and churches, traces of the Portuguese colonialism from the 16th century. Places of worship have been an important space of social interactions since the dawn of civilization, therefore play an important role in the life of the citizens of Dhaka. Mosques, which have always been considered as community centers as well, host thousands of worshippers every day and delete, during the times of prayer, every kind of social and economic gap between people. During the period of Ramadan, they host many people without economic possibilities, offering them food and drinks at the break of the fast. On Friday, the holy day for the Islamic belivers, the whole

community meets under the dome of the mosque for 5 moments of prayer during the day. Adults, children and the elderly attend this space on a daily basis and there are numerous activities offered for the community, such as Arabic language courses for children. Hindu and Buddhist temples are also important meeting places for the community, as they host, in addition to prayers, numerous cultural activities open to all. Free singing courses are offered to children and adults and people of all faiths visit them to observe the beautiful statues of which the temples are adorned. It can therefore be observed how much these spaces are lived by the citizens on a daily basis, as part of the culture and heritage of the place and thanks to its inclusive nature and community role.

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A General Public Survey was conducted to see if people visit the parks or not and, if not, the reason. It also asks what changes would encourage them to use them and why some people are willing to make longer trips to other more distant parks. The survey team managed the general public survey on 374 passers-by in the streets and public markets of the city of Dhaka. The goal was to find out whether the respondents visited their nearest park or not, their suggestions to encourage the use of the park and their reasons for visiting other parks in the city. The results were used to understand which measures could be effective to encourage people to start using the parks or to use them more frequently. The greatest concern was environmental problems, cited by 41% of respondents who did not visit the nearest park, followed by a lack of security and a lack of cleanliness. Out of a total of 374 respondents, 278 indicated what changes could make them use the park, make them use more often or make them stay for longer periods. The most common proposal was the furniture of the park, followed by protection against rain and sun.

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3.5.2 LACK OF PUBLIC GREEN SPACE In cities around the world, the provision of green space in urban settings varies by several orders of magnitude. Cities like Barcelona, Mexico City, and Tokyo have considerably less than the recommended nine square metres established by the World Health Organization. Conversely, cities like Chandigarh, New York, and Paris have more than double the World Health Organization recommendations. During 60â&#x20AC;&#x2122;s western planning standards recommend for 0,4 sq km of land per thousand of population for recreational purposes (Koppelman, 1969). Experts suggested that an ideal city needs to keep itâ&#x20AC;&#x2122;s 40%- 50% of land open, or free. In developed coun-tries of the Western World, 70% - 80% of land remains open. In these days the standard is revised and it is suggested to keep 25% land of an ideal city as open and green. However, the picture is different in case of Dhaka. In old Dhaka only 5% and in new Dhaka 12% of land is green and open, according to the Dhaka Metropolitan Development Plan (1995). It has been reported re-cently that

the total amount of open space including its roads, footpaths, parks, play fields, tracts, lakes, ponds etc. in Dhaka is about 17 -18% of city area. At present there is a dearth of open space, particularly Parks and Playgrounds, in Dhaka city. Whatev-er provisions were made in the original plans of the residential areas like Dhanmondi, Banani, Gulshan, were gradually en-croached, either by authorities themselves or by owners of adjacent lands. The same has been the fate of some of the lakes and canals of Dhaka. In Dhaka only 0.30% of the land is used for recreational activities, which is significantly low (280 square meters/1000 population) as compared to other major cities and falls far behind the standards set by the Detailed Area Plan of 2007. The primary threat to the stock of public open space comes from the encroachment both by public and private bodies. The government agencies themselves have completely or partly swallowed a number of parks and open spaces in Dhaka either by constructing community centers, government offices, etc. or by allotting plots for residential purposes. In this way, the small and intermediate sized open spaces/parks are in danger of encroachment. Even, the large scale parks or open spaces are also being threatened with encroachment. Large scale public projects are being placed in the available precious open spaces in Dhaka.

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To have a right picture of the present use and also to prepare future proposals it seems essential to have the facts and figures regarding the existing stock of open spaces. However, with multiplicity of controlling agencies, such figures are not readily available for Dhaka. Traditionally, the maintenance and control of open spaces of Dhaka have been shared by the authority of Public Works Department and RAJUK. Most of the open spaces and parks in local areas are handed over to the Dhaka City

Corporation authority as they collect tax from the citizens. The Arbory Culture Department of the Public Works Department only takes care of the large green areas of Dhaka. Beside these, other governmental agencies are responsible for their respective open areas like Zoo, Stadiums, Botanical Gardens etc., and several open spaces are under the authority of different institutions. As a result, in absence of any central control or legal binding such figures rarely determined and reported for Dhaka City.

3.5.3 PUBLIC SPACES: HABITS OF THE CITIZENS Following studies of the habits of the inhabitants of Dhaka on the use of public space, it has been revealed that regular users, coming for their own physical well-being, are the people with the highest income, are health-conscious and live nearby . They do not use public open spaces for recreational activities, as they can afford to enjoy in other places and at home. Moreover, they seem to keep their distance from ordinary citizens, arriving at exclusive times like early in the morning. Although the wealthy class of Dhaka represents a significant percentage of the total users of public green spaces, the majority is mainly the middle income group that comes for recreational purposes. It has been discovered that these middle-income people come from considerable distances, also facing transport costs, just to get relief from the exhaustion of hectic urban life. Sometimes they want in these open spaces more elements of active recreation such as exhibitions, cultural programs, entertainment facilities etc. The middle income group wants to use open public spaces for their total pleasure at a minimal cost. On the other hand, some low-income people come to these public open spaces to make a living or take shelter. Street vendors are at the service of other users and vagrants ask for alms. Some homeless and unemployed

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immigrants find themselves living in open spaces. The following diagram shows the basic nature of the use of large open spaces in Dhaka.

The diagram above shows that the three income groups use the same spaces for different purposes. Although they coexist in these spaces, it has been discovered that these three groups of people have different points of view to these spaces. The uppermiddle income group is often disturbed by the presence of low-income people. On the other hand, the low-income group turns to others for their need to earn. This situation is inevitable and the reality of our social system. However, many people in society consider this coexistence a cause of antisocial events. It has been commonly reported in the media that open spaces are places of antisocial activity. This idea is rooted in the minds of people who do not frequently visit these open areas. This survey notes that regular users rarely consider lack of security as a problem; and events of antisocial activity are reported in limited numbers. However, some people have

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reported being bothered by unauthorized people involved in antisocial events, such as prostitution, begging and drug addiction etc. And they ask for an additional security check. Therefore, it can be argued here that

the existence of the poor has no relation to anti-social events; rather this situation is linked to the maintenance and control system.

3.5.4 GOOD PRACTICE IN DHAKA: DHANMONDI LAKE AND HATIRJHEEL As the city is densely developed, it leaves little scope to have more open spaces on its inside. In this context, two existing urban projects have been studied for their great potential as public space, with the aim of improving the quality of urban life in Dhaka. The two analyzed projects are HATIRJHEEL as a prospective urban open space and its comparable intervention, DHANMONDI LAKE, both having the potential to effectively transform a neglected backyard into an active recreational open space and busy commercial strip respectively. Here, awareness towards some regular phenomena need to be addressed such as Illegal settlement, anti-social activities, taking drugs, mugging and similar activities.

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Beside this, the physical use of such open spaces depends on its facilities and amenities (such as landscape, age wise facilities, parking facilities, access facilities, games and sports facilities). For the livability of Dhaka City it has become imperative to develop adequate amount of quality urban green spaces especially at the time when rapid urbanization and enormous population growth challenge the public realm of this high-density city. Dhaka Structure plans remarks that Dhanmondi and Hatirjheel lake provide very important open space and recreation. Proposed other retention areas and major khal should be developed in similar way to prevent development encroachment and increase the limited open space and recreation areas in the city.

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DHANMONDI LAKE Dhanmondi Lake was once a navigational channel and connected to the surrounding river system. It structures the residential neighborhood and functions as a storm water drain.

the functions were appropriately placed: A few large green spaces were selected in strategic locations with better visibility towards the lake and accessible from within the neighborhood. To avoid direct traffic flow

from the busy and congested peripheral roads of the neighborhood, contributing to the major road network of the city, the functions were embedded in more localized areas.

The renewal of Dhanmondi Lake could serve as a model for restoring Dhaka’s water network. The Dhaka-based office Vitti Sthapati Brindo worked out the redevelopment strategy and the design of the lake’s waterfront. The Dhanmondi Lake redevelopment project is a paradigmatic strategic urban project which restores a significant water body, enlarges the public realm, and uses clever design strategies to avoid encroachment. Lakeside pavilions and stairs into the water accentuate the lake’s edge. Inexpensive, simple and durable materials were used for the park furniture and seating areas. The scheme looked for some moderate function that will generate less traffic in the residential area. Functions like, Food kiosk. Drink corner. Small restaurants, Community boat club, Community health club, Open air theatre and children’s play area, were distributed in different visually and spatially strategic locations throughout the development. The concept was to act these functions as attractor, to bring in more people in the lake side areas. To implement this idea

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HATIRJHEEL This public place was developed by the Dhaka-based architectural firm Vitti Sthapati Brindo along the lake named â&#x20AC;&#x153;Hatir jheelâ&#x20AC;? (Elephant Lake). The primary objective was to preserve the lake and its surrounding areas as retention basin. Later, at-grade roadway and walkway along the periphery of the lake was constructed. The lake and its surrounding areas were planned for recreational purpose covering an area of 1,3 sq km. The place is located in a prime location of Dhaka. It is well connected with the road network system.

city. Major objective of the projects include the preservation of low lying floodplain areas of Hatirjheel, the establishment of connectivity among major urban mobility corridors and the reintroduction of water based mode of transportation. Other goals are the integration of the northern and southern part of the city together with

bringing back the water front legacy by restoration and conservation of environment. Once a symbol of environmental degradation, Hatirjheel now symbolizes a remarkable example of environmental restoration and remains as a source of inspiration for environmental restoration throughout Bangladesh.

Hatirjheel is a wetland restoration project, which is a vital component to safeguard a large part of the city from flash flood besides bringing back the waterfront legacy once this city endured. This project encompasses a huge area with infrastructural and landscape components including, expressway, overpass, lakeside walkways, benches, viewing decks, floating amphitheatre, children park, water park, viaducts, taxi terminals. The place was well designed also with bridges and delightfully landscaped with trees and shrubs. In the initial days after its inauguration many people came to visit the place purposefully from different parts of the

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04 || ABSTRACT STRATEGY

4.1 issues

The city is considered one of the least livable cities in the world, ranked 137 out of 140 cities in 2017. It is the lowest for any South Asian city surveyed, because of, among other things, air pollution, severe traffic congestion, bad sewage system, slums and regular waterlogging. The list of the issues that afflict Dhaka is quite consistent and articulate. As an attempt to highlight the main problems that are currently making the quality of life of Dhakaâ&#x20AC;&#x2122;s inhabitants alarming poor and that are threatening the future of the city, three categories have been identified, i.e. water management, green and public space, mobility. These three fields group the problems that have emerged from the analysis and that have been previously investigated. Additional weaknesses that are affecting these three fields has been studied in this paragraph. WATER MANAGEMENT Water management is a crucial point in the policy for Dhaka because the city is already experiencing constant waterlogging and will soon struggle to provide clean water to its inhabitants. Waterlogging is currently the main threat for the city. In fact with only a couple of hours of medium intensity rain, the city gets flooded and consequently the traffic completely paralyzed. Rain events, which are particularly frequent during the monsoon rainy season from march to October, make

basically impossible to move within the city with detrimental effect on the daily life, which is completely disrupted. Despite the sizable amount of water on its surface, Dhaka clean water provision is almost completely supplied by ground water reservoir. The water extracted is more than the recharge capacity of the reservoir, thus the ground water level is dropping every year of about 15 meters. This clearly shows that an overexploitation of ground water is taking place and the deeper aquifer is no longer dependable as a long term sustainable water source. WATER POLLUTION The water of the rivers surrounding Dhaka has altered drastically from its natural state in terms of physical, chemical and microbiological composition and lost its suitability for any safe and beneficial use. Water Quality of the Buriganga, Turag, Balu and Sitalakhya rivers have reached an alarming level and the dissolved oxygen (DO) in many river water has almost reached the zero level in dry season. As the DO content of the river water as decreased below the critical level of four milligrams per liter it is posing threats to bio-diversity in and around the rivers. Generally, discharge of untreated industrial effluent, urban wastewater, agrochemicals, sewage water, storm runoff, solid waste dumping, oil spillage, sedimentation and also encroachment are major reasons responsible for pollution of Dhakaâ&#x20AC;&#x2122;s watershed. Industrial effluent discharged from

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Hazaribagh, DEPZ, Gazipur and Savar, and the domestic sewerage from a large part of Dhaka city through storm drain outlets are responsible for pollution of Buriganga-Turag-Bangshi- Dhaleshwari river system. Besides, people living on the rivers and canals banks throw their household wastes into the rivers. In consequence, the rivers have become a dumping ground of all kinds of solid, liquid and other chemical wastes. Encroachment of watershed areas is a common practice resulting in high trend of degrading of wetlands. The tendency of encroachment increases when the demand for land rises leading to rise in land price. Most of the natural drainages of Dhaka City disappeared or on verge of disappearance due to illegal encroachment. Encroachment on the rivers through unauthorized construction and dumping of solid waste is a source of river water pollution.

The surface water pollution is leading to health hazards. People living near the rivers and canals are often forced to use polluted river water unaware of the health risks. This causes spread of water borne diseases. The farmers using polluted water for irrigation are allowing toxic pollutants to enter into the food chain making human health more vulnerable. Solid waste and different effluents dumped into the rivers make it difficult for fishes and other sub-aquatic organisms to survive. Moreover, due to 160

river encroachment and dumping of solid waste, the canals and rivers are losing their natural flow. GREEN AND PUBLIC In the city of Dhaka, open space is in a vulnerable state due to illegal encroachment and mismanagement. In a city as dense as Dhaka, open spaces serve as the lifeblood for urban life. Therefore, green and public spaces must be preserved and increased to improve the quality of life of millions of urban inhabitants desperately seeking for recreational spaces. Poor management and lack of maintenance make the open space not usable and reduce the amount of open space. In the future, the lack of open space will probably become a source of health and social problems. The physical quality of open spaces is indeed very scarce in Dhaka. Existing parks and play areas are not properly managed by the authority. Although the country is very green, most of the open spaces are found barren and repulsive. The contribution of open space, as a physical element, focuses on three criteria: quantity, quality and accessibility. But most of the open spaces in Dhaka do not meet all three criteria. In the past, large green areas, mostly owned by private owners, were extended beyond the Dhaka city center border. However, as the city went through a phase of rapid transition, struggling with the challenges of urban sprawl, population, poverty reduction,

Building Resilience through Green-blue infrastructures

most tree-covered areas have been gradually transformed into urban habitats. Industrialization in the marginal urban areas caused rapid exhaustion of existing forests lands. Areas built within RAJUK border are living construction boom leaving little vegetation in the city of Dhaka. The process of exhaustion of green resources has proceeded with a fast pace, as the government had done no long-term planning to maintain the city green except establishment of a few parks and road plantations under the program of beautification of the city. 2013 national environmental policy urged to limit urbanization in agricultural land and guarantee urban plantation for ecological and environmental balance of man habitat. However, due to the lack of adequate policy to preserve the green in urban and peri-urban areas, It is predicted that the DMR will have to face the challenges of climate change at a serious level. WASTE MANAGEMENT Though, Dhaka recently adopted a Solid Waste Master Plan, sufficient waste collection services are not available in most areas of the city. Only 40–60% of Dhaka’s waste is collected and transported to the city’s two landfills. Uncollected waste is deposited in open drains and common areas, creating public nuisance and environmental hazards. Poor management of solid waste in the Dhaka Metropolis has aggravated flood problems and increased health hazards, including spread of diseases. The absence of

a proper solid waste disposal system meant that many fragile ecosystems have been used as dump-sites for all types of waste. Dhaka City generates approximately 1.65 million metric tons of solid waste annually. The waste stream is more than 80% organic matter and contains a wide variety of substances, such as food waste, paper, cloth, agricultural waste, construction debris, metals, hospital waste, and appliances. Per capita waste generation estimates range between 0.29 and 0.60 kilograms per person per day, depending on the individual’s level of income (higher income individuals tend to generate more waste). However, with rapid urbanization, increasing per capita income and changing lifestyle, the rate of waste generation is also likely to increase as also the percentage of recyclables and non-degradable materials. Dhaka is also experiencing .an ineffective

management of hazardous waste that is gradually becoming a threat to human health considering its long term impacts. The most adverse of them are that they can be introduced into the food chain through cultivation on contaminated land, and their impact on indigenous species. In particular inefficient waste management, the use of inferior technologies and limited facilities for treating industrial wastes, is generating severe pollution in many areas. AIR POLLUTION

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Air quality of Dhaka is a major environmental concern, especially during the dry season (November-March) when the density of airborne particulate matter (PM) reaches 463 micro-grams per cubic meter (mcm). During December-March the density of airborne particulate matter (PM) remains the highest. The most important pollutants are Carbon monoxide (CO), Sulfur dioxide (SO2), Nitrogen oxides (NOx), Ozone (O3), Hydrocarbons (HC), Suspended Particulate Matter (SPM) and Lead (Pb) that are mainly generated from fuel burning at high temperatures, motor vehicle emissions, chemical reactions in the atmosphere, combustion during industrial processes, transportation of vehicles and biomass burning, various kinds of vehicles, brick-fields, constructions, tanneries, navigation, corrosion of metallic parts, soil dusts. The results from continuous monitoring of the air quality obtained from the levels of pollutants are considerably above standards, especially in dry season, and they also show an increasing trend. It is reported from the World Bank and the Center for Enterprise and Society that up to 10% of respiratory infections and diseases in Bangladesh are attributable to urban air pollution. The problem has been found most severe in Dhaka, where air quality is the worst.

The environmental impacts arising from air pollution are increasing with the rapid growth of the city, intense industrial activity, huge population and increased motor vehicle. The vehicular air pollution 162

and brick making accounts for about 40 percent of Dhakaâ&#x20AC;&#x2122;s fine-particle air pollution. The deterioration of air quality can be a serious hazard to human health leading to pulmonary, respiratory and neurological illness as well as a reduction in visibility. MOBILITY Current chaotic transport system of the city is causing enormous socio-economic losses that can become a serious threat for the national development in fact Dhaka could consequently lose competitiveness in the world. In Dhaka, the traffic congestion cost is US$3 billion a year and the city losses over 8 million working hours daily (Osman, 2011). Like many other cities in developing countries, Dhaka is struggling with the serious problem of existing traffic stop and go situation. The large population growth that Dhaka is expected to experience is going to lead to the growth of vehicular traffic and further congestion. One of the main issues regarding mobility in Dhaka is the absence of continuous eastwest connectivity in the central area of the â&#x20AC;&#x2039;â&#x20AC;&#x2039; city. In the city, there is not a single continuous main road in east-west direction. The roads which are existing in this direction are all connecting roads or link roads. For discontinuity of the roads, huge number of T and staggered junctions have been devel-

Building Resilience through Green-blue infrastructures

oped on the layout of the city. So, vehicle cannot move thoroughly in east-west direction. Absence of east-west connection has become the major problem for the entire road network of Dhaka city, generating longer travel times and more congestion. One of the main reasons of Dhaka unbearable traffic jam is the lack of separation among traffic categories. On the streets of cars, motorbike, rickshaw, moto-rickshaw, carts, pedestrian and cyclist use the same space and they have to compete with aggressive aptitude to occupy the limited frontal space. There is clearly a lack of separation of different traffics and vehicles that is dangerous , reduces overall capacity and vehicular speed on roadways. Pavements, bike lanes, and a system of restricted lanes for motor vehicles and human/animal propelled vehicles are needed. There are about 100,000 registered rickshaws in Dhaka city, while the actual number of rickshaws in operation is around 500,000. Due to missing of separate rickshaw lane, the mixture of rickshaw and Motorized traffic is causing huge traffic jams. Dhaka has currently a remarkable problem in traffic management and public transportation, i.e. the absence of mass transport service. On this regard the City already planned the construction of 5 Mass Rapid Transit lines (metro) and 3 Bus Rapid Transit lines (a system of roadways that are dedicated to buses and gives priority to buses

at intersections where buses may interact with other traffic). The first line of Mass Rapid Transit is currently under construction, but it will not be probably finished for the end of 2019, as planned. Overall, the number of possible public transport passengers is so consistent that the development of other public transportation systems should be encouraged. The current public transportation is not comfortable and easy in Dhaka, especially to women, children or elderly due to poor accessibility and not integrated transport network. In the capital city there is a high rate (about 20%) of pedestrian traffic, but Dhaka is not pedestrian friendly at all. Pavements are often absent and when present, they are small and obstructed by street vendors, wastebins and other public and private equipments and activities. Road crossing is usually challenging due to the hectic traffic flow and the lack of proper facilities.

NOISE POLLUTION Noise pollution is adversely affecting the environment of the city and causing physical and psychological problems, and thus become an alarming health problem as it exceeds the tolerance level. In fact, the exposure to excessive noise level shows a threat to human health, especially for elderly people and children. Moreover, the traffic personnel, rickshaw pullers, open vehicle drivers, Strategy

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road side workers, small scale business enterprise workers are exposed for long-term noise pollution which might cause severe mental and physical health problems.

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4.2 strategy: A GREEN-BLUE NETWORK AS AN INTEGRATED SOLUTION TO URBAN ISSUES FOR A RESILIENT CITY

The project aims to create a resilient city. A dense metropolis that develop by positively adapting and transforming towards sustainability. An urban area capable to withstand chronic stresses and acute shocks that is already experiencing and that will face in the future while also increasing the life quality of its inhabitants. The proposed strategy to reach this goal consist in the implementation of a greenblue network through the city that is planned as an integrated solution to many different emerging problems in the city. The infrastructure mainly addressees the current and expected threats to the creation of a resilient city, which are the disaster risk s and the effect of climate change, The blue network in fact tackles the urban floodings due to waterlogging, which is a chronic stress in its milder forms and a recurrent disaster in its more severe forms. Waterlogging will be further aggravated by climate change, due to the increase in intensity and amount of rainfall. The green network will remarkably increase the presence of trees, plants and permeable soil that are essential tools to tackle the increase in temperatures that the changing climate will cause. In fact the greenery will reduce the amount of heat absorbent surfaces within the city (addressing the Urban Heat Island Effect), improve air quality, which will be degraded the rise of temperatures, and provide shadow which reduce the perceived temperature.

Through this green-blue network the city will be able to withstand both the consequences of the increase of average rainfall and temperature due to climate change and the extreme weather events that could possibly cause disasters. The project seize this process of urban transformation as an opportunity to address other main urban issues affecting the metropolis and hindering the realization of a resilient city, that have been investigated in the previous paragraph. In addition to its role as a drainage system to tackle waterlogging, the blue network will also serve as source of clean water to reduce the overexploitation of the aquifer, if the surface water pollution is contemporary solved. Besides increasing the amount of green and public space within the city, the strategy improve the conditions of the already existing and new spaces by dealing with waste management which is the main threat to their livability. Regarding the lack of separation of different traffic typologies, the network provides foot and cycle paths along the canals that will constitute new ways for slow mobility, where pedestrians and cyclists are separated from the vehicular traffic therefore they have safer and more pleasant journeys. Finally the network will offer waterways in an east-west direction, to overcome the lack of roads with this orientation.

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WATER SENSITIVE URBAN PLANNING After abusing urban water bodies through the years of hard use and neglect, when it has retaliated with unthinkable magnitude, there is a realization on the stake holders that they are valuable natural assets / resource for the community. The fact is that the contemporary planning process never took water systems as the driving force in any physical planning in this delta. Urban development with water bodies as focus was never given a trial during the rapid urbanization over the last 100 years. Review of Dhaka’s geomorphology reveals that for the sake of ecological, hydrological integrity and development sustainability, natural systems must be protected and increased. Studies show that much greater environmental as well as socio-economic success or advantages can be achieved through design with ecological principles in mind than without it. Water-bodies are resources in urban areas. Without proper action they disappear fast amid rising land prices. If sizable water-bodies can be preserved they can add to local aesthetics and become sources of recreation for all. THE IMPORTANCE OF AN INTEGRATED APPROACH Apart from reducing waterlogging vulnerability, the canals and water bodies also serve many environmental functions. They absorb heat generated by ‘urban heat island’, preserve bio-diversity, help recharge

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groundwater, can supply clean water and provide breathing space. It is important to consider all the beneficial aspect of canals and waterbodies so that the network can be designed to serve as a reservoir of safe drinking water, as a container of flood water, as open space and green area, as recreation and stress relieving spots, as a facility for low-impact water sports, e.g. diving, boating etc, as a tool to control micro climate within the city, as internal waterway, and as a tool for the conservation of biodiversity. THE IMPORTANCE OF A NETWORK Fragmented approach of planning must be avoided, thus the proposal of a network through the whole core city. In fact green areas and waterbodies inside the city remain as scattered and disintegrated elements with negligible contribution to environmental quality and ecological balance. A green blue network is delineated to protect, expand, and connect green areas and other environmentally sensitive areas within the city. This help to provide breathing space, promote ecological balance, preserve bio-diversity and promote wild life. The green-blue network would, among other things, democratize healthy outdoor recreation activities and access to nature by creating a network of linear parks. MOBILITY There is approximately 40 km of water-

Building Resilience through Green-blue infrastructures

way within DMA area with 13 inland waterway terminals on the banks of Buriganga, Shitalakhya, Turag and Balu River operated by Bangladesh Inland Waterway Transport Authority (BIWTA). In addiction waterbuses service is available in Hatirjheel. The new network of canals crossing the city serve also as waterway for electric waterbuses that will play a fundamental role in improving public transport service and addressing the mobility problems in Dhaka. In fact this water buses by traveling on canals, will not further increase the congestion of roads, but on the opposite less passengers will need to travel by vehicles on the road. Furthermore their implementation do not request the construction of a specif infrastructure, such as the metrorails for the Mass Rapid Transit, but they will simply travel in the canals built and connected for the creation of the green-blue network. The only cost specific to the implementation of this public transport mode would be those related to the floating stops and the buses. CLEAN SURFACE WATER SOURCE As there is no explicit sign of regional development programs outside core Dhaka, the pressure of increased population in the city is most likely to occur in the coming decade. In that case, the major challenge to face is to supply safe and necessary water for human intake as well as other domestic usages. Encroachment of peripheral rivers emanated from the unplanned and illegal

development of the city, associated with indiscriminate industrial and municipal pollution and thus made the treatment of the river water difficult. In addition, the alternative Government plan which involves borrowing water from the Meghna River to treat and supply will undoubtedly cost huge amount of money. In these circumstances, it is necessary to initiate ‘Loop Closing’ principle to protect, conserve and make sustainably usable the internal water resources of Dhaka metropolitan area. ‘Loop closing’ can be defined as the processes of collecting water from various sources, conserving, treating, supplying to various users and again collecting the used/waste water to make them usable again. It is possible to implement the ‘loop closing’ principle at a urban scale through the green-blue network. Ecological Resources and Biodiversity The strategy will turn Dhaka in to a biofillic city i.e. a city that provides close and daily contact with nature and seek to foster an awareness of and caring for nature. To avoid compromising the City’s natural resources and built heritage, environmentally critical areas must be preserved. The natural areas like river, khal, forest must be protected and preserved to ensure a healthy urban living. Failure to conserve natural ecology covering water bodies and traditional flora and fauna will affect ecology and livability in the future Dhaka City.

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Biodiversity refers to the variety of the biological resources e.g. living organisms. Wetland ecosystems are the major habitats of flora, wildlife and fishes. These aquatic resources have been subjected to rapid degradation as a result of population pressure, habitat destruction and other anthropogenic as well as natural causes. Waterbodies are decisive to the balance of ground water level as well as rivers and important for the sustainability of biodiversity. Wetlands ecosystems help regulate climate change by storing and capturing carbon sinks. Furthermore, wetland is one of the key components of ecotourism. The reduction of wetland is abolishing the rare pleasant precious recreation sites within the clumsy city. Some traditional livelihood like boating, fishing, collection of wetland weeds and lilies are disappearing as wetlands are being depleted. The vegetation of Dhaka City has a variety of indigenous and exotic species especially, in parks and gardens. It is estimated that nearly 41-46 parks/gardens have a wide variety of plants and trees. Besides, local species, many exotic species are planted along the roadside, old secretariat area and in residential bungalows for beautification. A large number of bird species are common in Dhaka, particularly pigeons, doves, kingfishers, parrots, jungle fowl, common pea-fowl, kite, fishing eagle, vulture etc. But many of these are now endangered within the city and are rapidly disappearing. One good point is that a large number of migratory birds cross

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Dhaka (especially seen in the lake of the National Zoo) in winter, Various species including ducks, seagull, falcons, harriers, plovers, curlews and sandpipers are seen there

Building Resilience through Green-blue infrastructures

during winter. The flood plains provide the most productive and diverse freshwater faunas. Over 3000 species of plants and 400 species

of fish and other aquatic fauna depend on wetlands for whole or part of their life cycle. The green blue network will provide a suitable habitat for this flora and fauna, increas-

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ing their presence within the city.

4.3 Goals and actions

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The project defines some specific action to materialize and implement the strategy that are explained in the following paragraph divided in three strategic fields 4.3.1 Water management Given the fact that Dhaka is subject to frequent flooding, an appropriate plan for flood control is needed. Such a plan is not evident in Detailed Area Plan (DAP, 2007), which rather than setting aside adequate space for water retention ponds and for permeable surfaces (including parks and other unpaved surfaces), focuses instead on roads and buildings, embankment and pump oriented flood control approach which will further intensify the suffering of Dhaka residents due to flooding. Contrary to the embankment and pump-oriented flood control and drainage management approach of DAP, flood management and a detention reservoir-based gravity drainage system is expected to be more reliable and appropriate for storm water drainage system in a floodplain landscape like Dhaka

with rivers encircling the city. In this section the actions taken to develop the blue network that serves as drainage system and clean surface water source are illustrated. GOALS Network of stormwater collection The green-blue network will serve as the main drainage system of the city. Rainfall will be in part directly collected by the canals and the rest will be widespreadly collected in a separate sewerage system (not mixing with domestic and industrial sewage) and then released to the canals. Storage of stormwater Heavy rainfall often overlaps with high water level in the surrounding rivers. In this situation the drainage system is not capable of discharging the urban stormwater by gravity to the rivers and pumping is required but the capacity of the pumpstations is not sufficient. Thanks to the introduction of detention areas, stormwater can be stored within the network until the water level in the surrounding rivers gets lower, thus natural

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discharge is possible or until heavy rainfall stops, thus pumpstations can gradually discharge the stormwater. Clean Surface Water Source Water is a basic human need. For healthy urban living safe water for all citizens must be ensured. Water has to be safe to keep the users free from diseases that affect productivity and increases cost of living apart from personal suffering. It is necessary to introduce a Loop Closing, that means to retain, preserve and purify the water collected from different sources and to supply the treated/clean water and again. In fact there exist number of water resources like rivers, khals,lake and water reservoir in and around Dhaka City which have to be protected and preserved for suitable water management and supply through the system of Loop Closing, by preservation of used water for further purpose through purification.

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ACTIONS Recovery of existing canal. The canals are responsible for the 80% of the drainage capacity of the city, thus the action aims to protect the still existing ones. In particular it consist of the rehabilitation of those canals which are in poor condition, especially the urban undeveloped canals, that have been shrunk by the buildings during the uncontrolled and rapid urbanization process and are now neglected space encroached by waste, informal settlements and land grabbers to activate new real estate developments. It is essential to identify the encroached water bodies and recover them as early as possible. At the same time it is important to prevent any encroachment in the future to avoid to further exacerbate the situation. In fact with the increase in land price the state owned water canals will probably become more frequently victim of grabbing. They must be protected to allow cityâ&#x20AC;&#x2122;s storm water drain-

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age to flow into the rivers. Protection of khals will help maintain effective drainage system enhancing a unique and valuable resource for the benefit of the health, safety, and welfare of the citizens for the Dhaka Region. It is necessary to delineate boundaries of all state owned water channels including khals and rivers based on cadastral maps and mark their flow and over flow zones physically with pillars and to maintain strict vigilance against any kind of unauthorized occupation and filling, while taking legal action against the violators. All kind of development for residential, commercial and industrial purposes in the manner of stilt structure must be strictly prohibited. Reconnection of the water lines through the re-opening of old canals. Of the 65 canal present Dhaka in 1960, only 26 are left today. Some of the 39 disappeared canals have been transformed into underground water lines such as boxculverts

Building Resilience through Green-blue infrastructures

or brick masonry ducts to leave their surface to new roads. In this way their capacity has been reduced as well as their positive environmental asset. In addiction they are more subject to the obstruction due to solid waste. Some other have been simply completely filled with sand and other material to generate new valuable land. It is necessary to initiate re-excavation of canals as needed to reconnect them in an effective network capable of collecting stormwater. Creation of detention areas Detention areas are basin usually dry, that can be flooded when needed, by receiving water from the a canal or pipe of the drainage system. They can store the water until it is necessary and then get back to their dry configuration, by letting the water flow back to the canal or pipe where it came from. Thus these facilities will not significantly reduce the total volume of runoff, but will redistribute the rate of runoff over

a period of time. Flood water detention areas are key and critically important component of the proposed flood protection schemes. The proposed detention areas have been designed to reduce the intensity of local flooding within the protected areas and also to reduce pumping requirements at times of maximum surface runoff. The detention ponds are proposed to ensure that cityâ&#x20AC;&#x2122;s natural drainage system is not compromised and that the effects of water logging are minimized. The old airport and the vacant areas of the tanneries are the two main detention areas designed by the masterplan, but they can be realized at smaller scale in any public and private area (if required by law for new developments) next to the network. Creation of infiltration areas. Infiltration areas are as the detention ones are basin usually dry, that can be flooded

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when needed. But infiltration areas are different from detention, because they are not directly connected to the drainage network. Consequently the water that gets stored in this basin, is not released to a canal or a pipe but infiltrates through the ground in the aquifers. Thus this kind of watermanagment facility does not only prevents floods but also help the recharge process of the ground water reservoir. The main infiltration area is proposed by the masterplan in the Old Central Jail which is located in one of the densest neighborhoods and most affected by waterlogging neighborhoods of the city. Smaller facilities of this kind could be realized in any public and private area (if required by law for new developments). Increase the capacity of the sewerage network Beside sanitation principles and hygiene (which are not the focus of this work), in or-

der to increase its efficiency the sewerage system has to be shifted to a separate systemâ&#x20AC;&#x2122; concept whereby used water is collected separately in a network of underground sewers that lead to a treatment plant whereas stormwater and surface runoff are collected in open drains and channeled to rivers and reservoirs. The municipalities and Dhaka Water and Sewerage Authorities have to build a widespread network of seweres, that serves all the areas that are currently missing this primary facilities, with a proper dimension and inclination of the pipes. In addition the already existing infrastructures should be enlarged to reach a proper cross-section and consequent capacity of at least over 100mm stormwater/hours. Constant Maintenance and Cleaning of the sewerage network. In addition to the construction work nec-

essary for the new sewerage network and the upgrade of the existing one, it is necessary to plan, implement and check the results of a constant work of cleaning and maintenance of these infrastructures. In fact due to the poor solid waste collection and management, a significant portion of the garbage remain on the streets and obstacles the inlets of the drainage system. Moreover solid waste enter the pipes and hinder the regular flow of water. On this regard Md. Sharif Uddin, engineer of Dhaka North City Corporation, claims that the capacity of a new drainage lines is reduced of approximately 60% in a couple of years due to solid waste. It is fundamental to keep the inlets of the system clean, and clean the pipe on a regular basis. Increase of the capacity and reliability of the pumpstations.

The existing pump stations need improvements to manage a bigger amount of water, even though the introduction of detention areas will decrease the stress on these facilities. In particular much effort and work any needed to enhance these facilities on a technical level in order to avoid any energy and mechanical failure in future, which are nowadays quite recurring. Phytoremediation This water treatment systems are designed to improve the water quality within the network, by the positive effects of plants, aquatic species and other natural elements. The water entering from the canals goes through different ponds, where pollutants and sediments are progressively reduced and it is finally reintroduced in the canal. This system has a minimum energy demand, since electricity is only needed for pumping at the inlet of the treatments plants, and

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does not requires the introduction of chemical products. Even tough these systems are not as effective and rapid as traditional water treatments plants, they are preferred because they are easier and cheaper to run, requiring only periodical maintenance. The network of canals within the city does not receive water from the surrounding rivers, but it just collect the stormwater from and discharge it to the rivers due to their location at the fringes of the city, their lower altitude and the embankment. Because of this configuration the polluted water of the rivers does not enter into the urban blue network. The pollution of the surface water within the city depends only by the pollutants poured into the canals in the form of domestic and industrial sewage and solid waste. Through the implementation of a separate sewerage network, that would divide sewage and stormwater runoff, domestic and industrial sewage would be collected and treated in proper water treatment plants before being discharge to the network. In addition the strategy proposes solutions to realize an effective solid waste collection and managements, that will be explained in detail in the following paragraph. Consequently to the implementation of this actions the two main reasons of the pollution of the water within the blue network will be removed. The water will be significantly cleaner and the phytoremediation systems will serve to reduce pollutants and

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sediments already present in the rainwater or deriving from the stormwater flowing on urban surfaces. All in all this natured based water treatment plants, despite being less effective than the traditional ones, will be enough for the network.

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4.3.2 public and green

Historically large open spaces with the lushness of nature surrounded the habitation of Dhaka. A famous Mughal garden ‘Bagh-e-Padshahi’ or ‘Bagh-i- Badshahi’ (Imperial Garden) was laid on the northern edge of the then Dhaka. Dhaka experienced a northward expansion, while the peripheral green areas were incorporated within the city boundary. During the British era, this green kernel was kept open at the center of the town and a green belt was developed by cleaning the water of Ramna Lake and by huge plantation in the surrounding areas in 1908. A race-course was established within that vast open space that was turned into the Sohrawardy Uddayan in 1972 with huge plantation. Part of this area was developed as Shishu Park in early 80’s. Dhaka’s interlinked central parks (Ramna, Shishu and Suhararwardi parks) still remain as an increasingly precious legacy with each passing years as the city center is being congested day by day. Moreover, National Stadium Complex and Old Airport area also become part of the green network. Considering the importance of green areas in central location for Dhaka’s environment, Dhaka Government had already emphasized to preserve the city’s

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central park areas. Additionally canals, water bodies and lakes are fundamental assets to be turned into recreational public areas considering their scenic beauty and shortage of open space in reality. In fact the project integrate to the network of canals and detention basins areas of greenery to create a green-blue network, constituted both by waterbodies and parks to provide with this infrastructure the most beneficial effects to the city.

To enhance the past heritage and the newly built parks a ‘Green Network’ is developed centering the Old Airport site turning it into the central green park of Dhaka. This is connected to Hatirjheel area linking Ramna Park, Sohrawardy Uddayan towards south; Sher-E-Bangla Nagar area, Zoo and Botanical Garden towards north-west, and Dhanmondi Lake. GOALS Increase of green public space In developed countries, a standard of 0,04 square kilometer of open space for every 1,000 residents is often used as a basis for estimating the demand for recreational use in a community. Communities frequently require additional lands to provide for the range of facilities desired by its residents and also to accommodate recreational demands from residents in nearby outlying areas. However, if a 0,04skm/1,000population

Building Resilience through Green-blue infrastructures

standardis applied in Dhaka, for 26 million people in 2035, the required open space will be 1052 sq.km, which is about 65% of Dhaka Metropolitan Region. Such a standard is simply unattainable and overly ambitious. Considering the prevailing conditions of Dhaka city, any ambitious and unattainable open space standard following western countries cannot be suggested. A requisite standard needs to be adjusted for different zones in Dhaka, like core city or beyond, based on the density of habitation and availability of open spaces. Anyway seize the construction of a network of canals and detention basin for water management purposes as an opportunity to provide more public space and increase the presence of trees and greenery within the city. It is proposed to re-create urban forest through protection and creation of vegetation and wetlands in the city, since they are essential for environmental and biodiversity benefits, economic and livelihood benefits, and social and cultural benefits beyond recreational use and aesthetics.

Effective solid waste management Proper management of solid waste consist in an effective management of final disposal of waste, collection, transportation and disposal sites. This is necessary to avoid, apart from health problem, the encroachment of canals and the hindering of sewerage network’s pipes and inlets. Furthermore a proper waste management prevents surface- and groundwater pollution and general pollution of the total environment (water, air, soil). Mitigation of the increasing temperature and Urban Heat Island Effect Due to lack of proper policy to preserve the green in urban and peri-urban areas, it is predicted that the Dhaka Metropolitan Region will have to face the challenges of climate change in serious level. In this course, the concept of urban and peri-urban forestry and greening particularly is a promising approach to tackle the detrimental effects of the increased

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temperature. New green areas will reduce the amount of heat absorbent material, increase air-quality and offer shadow to those who does not have access to air-conditioned environments. ACTIONS

Linear Park along the canals An interconnected network of green spaces is created by linear park along the canals connecting all existing major parks, nodes and open spaces including road reserves, Connecting Dhaka University area with the green network will lead to the opportunity to establish an eco-friendly’ campus. Green network at the city is designed also for wildlife as ecological corridors. This also provide a recreational facility for the residential communities through which it traverses.

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In fact a linear park will be more easy to reach than a punctual facility, does their benefit will affect a major number of Dhaka inhabitants. Parks in detention and infiltration areas All the designed detention and infiltration areas will be arranged and equipped as parks in a program of urban and peri-urban forestry (UPF), which consist in the planned, integrated, and systematic approach to the management of trees in urban and peri-urban areas for their contribution to the physiological, sociological, and economic wellbeing of urban society. These urban greening will be an increase of vegetation to improve the environmental quality, economic opportunity, and aesthetic value associ-

Building Resilience through Green-blue infrastructures

ated with the city’s landscape. Solid waste awareness raising campaign Creation of environmental awareness among people is necessary, community people from all level of income, age and education should be encouraged to take part in taking care of the environment. Environmental protection can best be achieved by means of making people aware of the consequences of environmental degradation. Awareness can be raised through publicity in the form of, TV advertisement, newspaper supplement, drama to reduce resource consumption and waste production, cleaning up the urban environment at the individual as well as household and community level. Seminars and workshops should be organized to share information. Public information will be provided to raise awareness of the causes and impacts of environmental degradation, encouraging

debate on environmental priorities and strategies, e.g. through workshops involving experts and people, that would produce a people centric action plan. Effective solid waste collection, transportation and final disposal. A widespread network of ecological islands where citizens can dispose their domestic waste will be implemented. From there waste will be collected and moved to “solid waste transfer stations” that will be located one in each neighborhood. The location of these solid waste transfer station is based on ecological criteria (odors, waste spillover, outbreak of rodents, insects, aesthetics, risk of water pollution, noise level, condition of meteorology), transportation criteria (infrastructure, proximity to a major road or railway, restriction on truck size and weights, interference with regular traffic volumes), economic criteria (construction cost, main-

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tenance costs, transportation costs to and from stations, land value of station and surrounding area) and spatial criteria (distance from collection areas to station and from station to disposal area, land uses near station site, size of served population and its waste characteristics, availability of vacant land, site topography, existing and planned stations, future planning of the community and region.

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Come to the Dhaka metropolitan area grows to its targeted future population of over 26 million, there the demand for the public will be increased transport service An efficient, safe and reliable public transport system including waterbuses and mass rapid transportation services that the general public can afford to use will be required bring people to work and to their public entertainment. Communities will find better plac-

es to live and work with easy and safe access to social and economic opportunities, whether in core part of Dhaka City or in regional and sub-centers of Dhaka Metropolitan Region. An effective network of connectivity will foster the safe, efficient movement of people and goods and contributes to Dhaka’s economy. Mass transits directly connected to other transportation modes is vital to move people within Dhaka Metropolitan Region. Comprehensive and efficient transportation systems is essential to ensure Dhaka’s position as a modern city and to serve the administrative, financial and commercial capital of the country. The city must be able to provide an efficient and equitable transport infrastructure which will allow all members of the community equal access so that everyone can enjoy the maximum benefits of city life.

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Privileging soft-mobility Measures to encourage people to move around the city on foot or by bike are taken. In these way the environmental impact of their journey is flattened. Additionally these habits let people exercise on a daily basis without spending time for it and consequently have beneficial effects on their health. Considering the severe traffic congestion of the city, cycling and walking are suitable modes of transport for short and medium distance journey, if proper lanes and facilities are provided. Making public transport more convenient Public transportation is the means of reducing traffic congestion, providing an economic boost to the areas of job relocation, and most importantly, contributing to a green environment by reducing carbon dioxide (CO2) emissions. Using Public transportation can result in a reduction of an individual’s carbon footprint by saving CO2 emissions. Public transportation can help to alleviate traffic congestion as well as to promote a more efficient land use. Social balance is also maintained by providing efficient and effective public transport because low income cannot afford to own and operate private car. Beside being more convenient than private vehicle on a ecological level, public transportation is also a faster mode of transport. In fact the new mass rapid transit, bus rapid transit and waterbus lines will all travel on a separate way, without interfering with roads traffic

Building Resilience through Green-blue infrastructures

and among them. Thus, avoiding the severe Dhaka’s traffic congestion, they will be less time consuming. In addition, the big amount of expected passenger will allow low fares, making it accessible also to lower income groups. Making public spaces easily reachable It is important to provide easy accessibility to the new green areas within the city both for the residents of the surrounding areas and for people coming from different neighborhoods. For this reason it is necessary to work on accessibility on two interrelated levels: public transportation access and soft mobility access. All the detention and infiltration parks will be served by public transportation, with stops of the metro, bus mass transit and/or waterbuses. All the linear parks on the banks of the canals will be located along the waterbus lines, so they will be easy accessible through this public transportation mode and will also be served by interchange stops with metro and bus mass transit. For all these green facilities as many entrances as possible will be de-

signed to allow pedestrians and cyclist to enter them easily. In addition pedestrian/ cycle road crossing will be arranged at their entrances. The linear park is more rapidly accessible by a bigger amount of city dwellers than a punctual facility. Thus the implementation of the network will provide a green relief close to many residential areas. People will be consequently more encouraged to take advantages of these spaces, since significantly more people visit the nearest park if it closer than 1km to their place, than if it is further than 1km.

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actions Pedestrian and cycle paths along the canals

These bicycling and pedestrian path and sidewalks offer an opportunity for people to move around the city without leaving an essentially green environment (soft traffic corridors for the pedestrian), which is often safer and quieter than roads. Electric waterbus lines The new and existing canals will serve as waterways for a network of 4 waterbus lines crossing the city both in north-south and in east-west direction, along which much connections are needed since the lack of main roads on this direction. Line 1 travels from Dhanmondi Lake all the way north through Hatirjheel(on the east

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side of the city), turns west before the International Airport and eventually goes south on the opposite side of core Dhaka through Uttara. Line 2 encircles the Old Dhaka (the southern part of the city), starting from the former tanneries area, passing through the university area and ending at the river port. This area is particularly affected by traffic congestion, thus this line will remarkably enhance the access to this area. It connect to line 1 and 3 at Dhanmondi Lake. Line 3 starts from Dhanmondi Lake at the intersection between line 2 and 1, moves north on the west side of the city through Ramchandrapur Canal and than turns west in Kallyanpur Main Canal, crosses the city in east-west direction, also passing through the old airport park and finishes in Hatirjheel at the intersection with line 1. This line is fundamental to alleviate the traffic congestion and to provide an efficient transportation

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mode from east to west and vice-versa, since main roads in this direction are missing. Line 4 starts inside the old airport park, close to the National Assembly Park and moves towards north all the way through the park and the city, in its middle, until it reaches line 1 in Mirpur. It additionally connect s to line 2 within the old airport park. Integration of pedestrian and cycle paths and waterbus lines with the planned metro line

It is necessary to create a fully integrated multimodal transportation system connecting all the new modes of public transport. The designed waterbus stops are located along the continuous, pedestrian friendly system accessible to all including the disabled and complemented by a bicycle lane network, built

along the canal. This system of pedestrian and cycle path is fully integrated with the new metro lines (mass rapid transit) and bus rapid transit lines. Furthermore also the waterbuses lines proposed by the project have interchange station with mass transit lines. Vehicle traffic limitation The traffic of motor vehicles is limited on the canals banks. In some of the densest neighborhoods of Dhaka the canals have been shrunk by the roads and buildings without leaving any empty space around theme. In this particular situation roads alongside the canals banks have been transformed into pedestrian/cycle paths and green areas, for the implementation of the green-blue network also in these particular situation. In these cases the vehicular traffic flow has been redirect to parallel streets. These sit-

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uation is found in dense residential areas where there is no transit traffic, but only vehicles reaching private buildings. Consequently this transformation in the traffic asset will not worsen the traffic congestion. Moreover the possibility to access to the private buildings in case of emergencies or special services has been maintained, by leaving proper empty paved surfaces.

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05 || ABSTRACT PROJECTS

5.1 Ramchandrapur canal: the banks

The Ramchandrapur Canal is part of the system of canals that flow into the Kallyanpur Main Canal, which then drains in the Turag river. Waterlogging at the residential areas of Kallyanpur, Ramchandrapur and the surrounding areas has been a regular feature of the recent years. Residents of the area claim that the prolonged waterlogging with sewerage water has an adverse impact on the lives and health of the people living in there. According to a 2007 Dhaka Wasa survey, the 2.2km Kallyanpur main canal was 1836m wide. Encroachment by land-grabbers has narrowed the width of the key drainage route down to 10-12m in many places. Various establishments had been built near the banks of the canal adjoining the Hazi Market at North Shyamoli, and also on both sides of the Kallyanpur sluice gate, violating the Wetland Conservation Act and the Dhaka Detailed Area Plan (DAP). Several illegal bamboo structures can be seen on the Kallyanpur main canal. The dumping of non-degradable waste, such as polythene bags, has also reduced the depth of the water body to 7-8m. Illegal structures continue to grow on the canalâ&#x20AC;&#x2122;s five branches â&#x20AC;&#x201C; Kallyanpur Ka, Kha, Gha, Unwa and Cha canals. On the southern part of Ramchandrapur Canal (which is also known as Katasur Canal), illegal buildings have cropped up on 150 square meters on both sides, and most of the canal is filled with solid waste. A mosque has been established on the southern part

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of the Number 3 road culvert near Mohammadpur and Nobody Housing in the city. The 2.94km-long Ramchandrapur canal, which used to be 18-30m wide, has lost its natural flow due to rampant construction and the persistent dumping of waste. The canal has now become a breeding ground for mosquitoes, A multistory building has been built on the canal near the Dhaka Wasa water pump station, while the city corporation has built a 10m wide road by filling up the canal. The system of canals is shrunk by the buildings and roads within one of the densest residential areas of the city. These canals are those in the poorest condition within the core city due to waste dumping, water pollution, illegal encroachment of informal structures and buildings. In particular the project focuses on the rehabilitation of the Ramchandrapur canal since it is the most endangered. In fact its natural flow of water

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has been disrupted by illegal structure and the canal will most likely completely disappear if effective actions are not taken immediately. To protect the banks from encroachment, landscaping measure are implemented: a continuous paved footpath on both banks is built to demarcate the canal premises and green areas are arranged along them in the free space available. Additionally in the highly dense urban fabric, empty residual spaces are found; they are exploited as much as possible since they are rare and generally small sized. These vacancies are converted in green public spaces privileging organic shapes for a more natural appearance, thus enhancing the presence of natural elements within the city also on a perceptional level. The development of these linked facilities will be examined in the following paragraph.

Building Resilience through Green-blue infrastructures

5.1.1 Transforming the section The cross-section of the canal is adjusted to allow a bigger drainage capacity, in particular in extreme rainfall events and to allow a more pleasant use of the banks. The western bank has a road along it for most of its length, while the eastern one is mostly non accessible and has buildings on or really close to the edge of the canal. Due to these different characteristics of the two sides of the canals and their surrounding the two banks are developed in two different design. They have in common the presence of a continuous cycle and pedestrian path and the integration of trees and plants in the empty space between them and the surrounding buildings. On the western bank steps degrading from the path to the water are realized. This solution is a modern reinterpretation of the traditional space of the ghat, a series of steps leading down to a body of water that is used for economic, recreational and reli-

gious purposes. The concrete steps are interrupted by green areas, to integrate the presence of natural elements in this facility, offering a more pleasant and fresher environment. Thanks to this spatial arrangement people could make use of the banks of the canal as a recreational spot and breathing space. The western bank will be consequently turned from a neglected and gray infrastructural space into a green space for the community. This shape of the section will allow the canal to contain more water on the high water level periods. On the eastern section the limited empty space available, does not allow a similar intervention. Thus the original section is kept on these side. Where the buildings lay on the banks, without any empty space between them and the canal, the foot and cycle path is built as a cantilevering structure, in order to create a continuous route without reducing the cross section of the canal and its capacity.

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5.1.2 Materials and plant species Being such a narrow canal, the canalbed and banks are realized in reinforced concrete. In some parts the canal present already these arrangements. This material is not matching the idea of creating a greener city but in this narrow configuration it allows the canal can to have a rectangular cross section. Natural banks, would have required to be sloped, consequently reducing the cross-section and the drainage capacity, which has instead been considered the most important principle. To increase the presence of natural elements also on the artificial banks, the degrading steps are interrupted by green areas, which contain plants and bushes typical of wetlands that can be flooded and live altering periods underwa-

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ter and dry. It is suggested to mix Phoenix paludosa (mangrove Date Palm), Acorus calamus (sweet flag), Chrysopogon zizanioides (vetiver grass), Amaranthus paniculatus (marvel bronze), to create a non-monotous landscape. The foot/cycle path on the eastern bank is realized as a reinforced concrete structure since it is in many points cantilevering. A lawn and trees are located in the empty space between it and the surrounding buildings to create a green pleasant environment and as part of the effort for urban forestry. On the western bank a road was present in most of the canalâ&#x20AC;&#x2122;s length. This road is transformed into the pedestrian/cycle paths and green areas, for the implementation of the

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green-blue network also in these particular situation. The vehicular traffic flow has been redirect to parallel streets. These situation is found in dense residential areas where there is no transit traffic, but only vehicles reaching private buildings. Consequently this transformation in the traffic asset will not worsen the traffic congestion. Moreover the possibility to access to the private buildings in case of emergencies or special services has been maintained, by leaving proper empty paved surfaces on the western edge, where the buildings have their accesses. Along the degrading steps on the bank a stripe of lawn with trees is designed to provide shadow to the people on the steps and on the adjacent bike/pedestrian lane.

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This lane is paved with colored asphalt to clearly distinguish it as a transit area and avoid people to stop on it. The remaining space between these colored transit lane and the road that is used only occasionally for the access at the building for special needs has a variable width and it is covered by lawn with trees. It is suggest to plant a mix of trees as follows: Trachycarpus fortunei (windmill palm), Delonix Regia (flamboyant tree), Tectona grandis (teak), Peltophorum pterocarpum (copperpod), Bauhinia variegata (kanchan tree). Besides providing shadow ,they bloom in different periods with flower of different colors, creating an attractive atmosphere.

Building Resilience through Green-blue infrastructures

5.1.3 electric waterbuses and stops Waterbus line 3 travels along the Ramchandrapur canal in and serves six stops in both directions. According to the different seasons and weather conditions, the water level in the canal will vary. To ensure that the stop level is always at a suitable position in regard to the level of the boat, for all passenger to easily get on and off the bus, the bus stop is floating. In this way the stop and the boat will always be at the same level, to allow disabled, elderlies and children to safely get on and off board. The bus stop is made by a floating pier, similar to those of the touristic

port, linked to the river banks. The pier gets consequently higher and lower according to water level. It is located in a niche, specifically made in the bank, to avoid the bus stop hindering the transit of waterbuses in the narrow section of the canal. The different level of the pier and the bank is solved by a ramp which is fixes on the bank and rolls onto the pier, changing its slope to adjust to the different altitudes of the pier. On the floating pier a wooden structure is fixed to shadow and protect the passengers waiting to get on board. In addition the bus stop is equipped with benches, to provide a more comfortable wait and travel experience.

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The boats used are flat-decked, single-level vessels that have small dimension to nimbly move also in the narrowest canals, like Ramchandrapur. In fact they are only four meter wide, twelve meter long and four meter high, of which less than two are underwater. Thus this prototype is suitable also for canals which are not particularly deep, especially during dry season. Although their minimum dimension, they can carry over hundred passenger, of which more than fifty can take a seat. Water buses are fully accessible by wheelchairs, strollers, baby buggies, and wheeled luggage, and there are no steps between the entrance and the passenger cabin. The boats also have large open spaces in the center, by the boarding area, where passengers can stand and enjoy the fresh air. A closed seating area is in the stern, behind the cabin, while a smaller open seating area with benches is available in the bow. Riding a waterbus is not any more complicated than riding a subway and way more

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easier than getting on and off a bus on the congested streets of Dhaka, where buses do not stop at designated bus stops and passengers have to get on and off board, while the bus is moving or is stuck in traffic jams, in the middle lanes of the road. These boats are propelled by an electric engine, thus they do not produce any water, air and noise pollution. The engine is powered by batteries and additional energy is directly supplied by solar panels on their roof. Overall this transport mode is clean and safe both for the environment and for passengers and staff. In addition citizens starting to take advantage of the waterway would establish a relation to the waterbodies and perceive them as an useful resource for the city. They would probably be consequently discouraged to encroach, ruin or impoverish the canals and their premises.

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5.2 Ramchandrapur canal: facilities

The vacant areas adjacent to the canals are converted in green public facilities to increase the urban forestry and supply additional public space to residents of the area with different uses. In particular along Ramchandrapur canal 7 different vacant areas are found. According to the uses of the buildings in the surroundings, their accessibility, the proximity to the waterbus stops and their dimension they are designed for different uses, having in common a strong green character and a remarkable presence of natural elements. Following a series of re naturalization projects of urban areas, organic shapes are privileged to give a more natural appearance to these areas, thus enhancing the presence of natural elements within the city also on a perceptional level.

5.2.1 Integrating water management in public spaces The provided facilities include water parks with phytoremediation, sport fields, floating markets, open air amphitheater and spaces for arts and exhibitions. All these areas have a double value as public spaces for the communities and water management infrastructures. In fact in all these vacant areas, small detention basins are arranged to redistribute the rate of stormwater runoff over a period of time at peak flow of the canal. Considering that peak flow is experienced during heavy rain events, when open air public spaces would not be anyway used by citizens, the integration of the double use of these areas does not affect their value and availability as public spaces..

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5.2.2 Mohammadpur sport fields This area in Mohammadpur residential area, is one of the biggest vacant land adjacent to the canal. Thanks to its sizeable dimension it has been possible to design it as a sport facility to supply spaces and equipments to excercise and practice team sport for people of every age and income status, fostering also the social relationship within the neighbourhood. Due to the irregular spatial configuration of this area, it has been divided into three main spaces. A northern small clusters, which is shrunk by the sorrounding buildings is turned into a skatepark, due to its more urban and artificial connotation. The biggest area in the south is converted into the proper sportfield with a cricket pitch encircled by a running path. Additional sport areas, training equipments, toilets and linked facilities are integrated to them. The central area, crossed by the canal is ar-

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ranged as a traditional park area with cafes, offering recreational spaces both to people coming there to excercise or just for leisures. the two sides of this area are linke by a bridge. All the three areas are integrated with detention basins, The skatepark is realized as a concrete hollow, on which youngsters skate in the dry days but it retain water during heavy rainfall. The cricket field is at a lower level than the sorrounding running path and lawn, thus it constitute a detention basin, which is paved with tartan to allow to play safely and confortably. In addition this material gets dry more rapidly than a lawn, allowing people to re-use the pitch sooner after flooding and prevent excessive cost of maintenance for a lawn that is oftenly flooded and can remain under water for days. The detention facility in the central areas is a naturalized basin, with swamp vegetation that can be regularly flooded.

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5.2.3 Public health: exercise and diabetes Bangladesh is home to the third largest diabetic population in the world with 8.4milion people affected by these disease, i.e. the 10 percent of the population. Only China and India have bigger diabetic population with respectively 90 and 61.3 million but they also have a larger population, in fact the percentages are respectively 9 and 8 percent of the population. This reveals that Bangladesh is the country with the highest share of people affected by diabetes. Exercise is proved to be one of the most powerful tools that to tackle diabetes by controlling body weight and blood sugar. Exercise additionally lowers blood pressure, reduces harmful LDL cholesterol and triglycerides, raises healthy HDL cholesterol, strengthens muscles and bones, and reduces anxiety. Furthermore exercise increases the body’s sensitivity to insulin. All forms of exercise — aerobic, resistance, and a combination of both — have been shown to be equally good at lowering insulin resistance in previously sedentary older

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adults at risk for diabetes. People with diabetes who walked at least two hours a week are less likely to die of heart disease than their sedentary counterparts, and those who exercised three to four hours a week cut their risk even more. Women with diabetes who spent at least four hours a week doing moderate or vigorous exercise had a 40% lower risk of developing heart disease than those who didn’t exercise. In this context it is fundamental to provide to urban inhabitants proper space to exercise and practice sport, which is currently lacking in Dhaka. The implementation of sport facilities will encourage people to have an healthier life style at any age and in particular will supply to young children a safe place to spend time with their friends while playing sports. They will consequently grow developing a sport life style and will probably keep this habit through their entire life.

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5.2.4 Mohammadpur open air amphitheater In a smaller area of the Mohammadpur residential area an open-air amphitheater, working also as a detention basin, is designed. This space dug into the ground is constituted by degrading terraces with a circular shape. During the dry periods it can be used for theatrical plays, small concerts, events, public gatherings, projection of movies or sport matches, etc or simply as a recreational spot for residents to gather and spend time outdoor. During the peak flow the amphitheater receives excess stormwater from the canal, temporarily stores it and gradually releases it over a period of time back to the canal. This typology of public spaces are particularly popu-

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lar in Dhaka. In fact open air amphitheaters are found in all the main public parks and lakes and are frequently visited by citizens both on the occasion of events or as regular public spaces. Particularly famous are the amphitheater in Dhanmondi Lake and Hatirjheel, which have significantly different characteristics for dimensions, material, spatial arrangements and relation to the water, but are based on a common scheme. This facilities get particularly crowded for examples when the football and cricket world cup matches are displayed. In this and other cultural and entertainment occasion, people of different age and social status come together to spend time in the same place, fostering the social strength of the community.

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Open air amphitheater in Dhanmondi Lake

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Open air amphitheater in Hatirjheel (https://www.theguardianbd.com/ rajuk-integrated-development-of-hatirjheel-begunbari-khal-area/)

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5.3 DETENTION PARK AT TEJGAON OLD AIRPORT

The British had built military airstrips at Tejgaon during the Second World War for operating warplanes towards the Battle of Kohima and other Burmese war threats. Soon after the Second World War broke out, the British authority felt the need to build Royal Indian Air Force (RIAF) stations in Dhaka and other vulnerable places in Bangladeshi territory. The construction of Tejgaon Airport started in 1941. The airstrip at had military fighter plane landing facilities and the British Royal Air Force used the airstrips for maintenance and storage of their aircraft. There was also an United States Air Force detachment here during the war. The first RIAF light fighter landed on the underâ&#x20AC;&#x2018;construction runway of Tejgaon at the beginning of 1943. After Independence in 1947, development of the airport facilities was undertaken and Tejgaon became the first airport to operate civil aviation in thenEast Pakistan and it was also a station of the Pakistan Air Force. Today it is a part of BAF (Bangladesh Air Force) Base Bashar. Following the transfer of civilian flights to the newly built Shahjalal International Airport in 1981, Tejgaon was taken under the control of the Bangladesh Air Force. 5.3.1 Tejgaon Old Airport today and its surroundings In mid-2011, frictions started between the Bangladesh Air Force and architects, planners and civic activists who started to claim

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that keeping this airstrip unused since 1988 in the city center, is seriously affecting Dhaka city’s development Also the “Dhaka Structure Plan 2016—2035” claims that some large scale open spaces in Dhaka, such as Old Airport and the Old Central Jail are under forced occupation by government and semi-government bodies preventing their use as recreational public space. Current facilities in Old Airport need to be removed and to be used for civic facility, like detention basins, parks and green open space. The area is located in a strategic central position of the designed green-blue network, providing a sizable area for canals, detention, basin and parks that connects different sub-systems of the network. Louis Kahn’s monumental Capital Complex at Sherebanglanagar is located on the

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south-west of the Old Airport. Several government, administrative and cultural facilities, that play a fundamental role in the life of the city and of the whole country, are located in its surrounding in an administrative neighborhood. On all the other side the airport is surrounded by residential areas, with shops and offices on the main roads. In particular the northern area is a middle income residential area with a medium density. On the east side the density is lower because it is a prestigious residential area, while on the south, although it is a medium income residential area as well, the density in higher. around the Tejgaon Airport, several government departments and commission and an important international conference center are located close to the National Parliament House, Many cultural facilities are present in the area such as the National Library, the Planetarium, the Liberation War Museum

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and the National Museum of Science and Technology. Additionally many colleges, university, hospital and medical colleges are spread around the old airport. If compared to other urban parks in Dhaka City, the old airport is clearly one of the biggest open spaces in the city. The comparison is also extended to famous urban parks in big western city and Tejgaon area is proved to be almost as big as half Central Park in New York City. This gives in a glimpse a clear idea of the dimensions and conse-

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quently of the potentiality of this space within the densely urbanized context of Dhaka. 5.3.2 design principles In a highly dense built up environment, people are constantly immersed in a urban landscape made of regular geometric shape, which are typical of the artificial elements of which the city is made. Organic shapes and richly wavy patterns are on the opposite usually linked to natural elements in the collective image. Following this idea

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that has been proved by perception studies and implemented in many urban and landscape project of re-naturalization of waterbodies, the new interventions on the area (such as waterbodies, footpath and greenery) are designed privileging organic shapes for a more natural appearance, thus enhancing the presence of natural elements within the city also on a perceptional level. Traces of the former airport are kept to maintain clear evidences of the history of the area and its identity. Consequently some characteristic buildings are kept and con-

verted to new uses, while the trace of the peculiar element of this open space, the airstrip, is kept even if it is converted to a green permeable area. In fact the asphalt surface of the airstrip is removed, but its area is kept as an empty lawn (only crossed by footpath and the canal) surrounded on all edges by trees. For the visitor the geometry of this facility will be still clearly perceivable, but he/ she will be surrounded by a more natural landscape. The park is developed following the princi-

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ple of integration of the elements, already existing in the former airport, in the new design of the park. Consequently the canals and ponds for the phytoremediation get their basic configuration by the already existing lakes. The existing roads are deduced in their dimension, to leave more empty permeable green space, while a new widespread network of pedestrian and cycle path is arranged to provide eased accessibility to all the area of the park. The trees already present in the airport are kept in place, and integrated in wider areas covered by trees. 5.3.3 Uses and facilitieS Within the large former airport area different facilities are arranged serving as watermanagement tools and public space for the community. In addition they all play an important role in increasing the environmental asset of the area and in providing close and daily contact with nature and seeking to foster awareness of and caring for nature. TOURIST CENTER This center will provide information to local visitors and tourists about the amenities of the park and more in general about the city, helping them with accommodation, transport, sightseeing, food, etc. It will additionally provide basic services such as toilets, lockers and luggage storage, Internet access, mobile devices charge points, etc.

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BIKE RENTAL Bike is a suitable option to go around the park, since its sizable dimensions (over three kilometers in length. This facility will rent bikes to visitors for short periods, to reach rapidly their desired destination within the park, or for longer times (until one whole day) to let the visitors enjoy all the attractions and areas of the park. RESTAURANTS AND CAFES Cafe and restaurant will provide food and

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beverages to the visitor, and will attract themselves people to the park. Located in already existing buildings, they offer different options to match the needs and economic means of the different social and income groups. They are accessible by vehicles for service and supply purposes. ENVIRONMENT EDUCATIONAL CENTER The center is located in the main building of the former airport terminal, in a preeminent and spacious location. It will host con-

Building Resilience through Green-blue infrastructures

ferences, workshops and exhibitions related to the environment for children, youngsters and adults, to raise awareness about the environmental issues of the city and the planet and to promote more ecofriendly lifestyles. BOTANICAL GARDEN This facility is linked to the environment educational center, helping to raise awareness about biodiversity. In this area visitors can learn about the plant species typical of Dhaka . A particular focus is given to wet-

landâ&#x20AC;&#x2122;s and water species to emphasize the fundamental and peculiar relation between the ecosystems and the waterbodies in the region. BOAT RENTAL AND SAILING AREA Waterbuses do not travel in the final part of the canal, since it is located after the last stop. This area is consequently used for sailing for leisure. Sailing boats, kayaks and paddle boats are rented out to visitors to enjoy the park also through the water. This possibility of water recreational activities,

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will contribute to create a relationship between the citizens and water. OPEN AIR ARENA The final part of the airstrip is arranged as an open air arena for concerts, plays, conferences, public ceremonies and other events. The facility has a versatile configuration, in fact it can be expanded in the empty lawn on its back. In this way it is not dispersive during the smaller events but it can host considerable amounts of people during the bigger ones. FISHING AREA This area of the canal, where water buses do not travel, is equipped with floating peers to provide a space for fishing. This sport is in fact really popular among locals, that will now have the possibility to practice it in the core of the city. Fishes will be attracted here because of the flow generated by the outlet of the phytoremediation ponds. FLOATING MARKET This area is arranged with floating piers and small boats from which groceries and snacks are sold . This is made in an effort to limit the vendors in an appropriate space, avoiding that visitors will feel bothered by them in other areas of the park. The floating market will additionally provide a pleasant atmosphere for costumers. AIRFORCE MUSEUM The already existing Bangladesh Air Force

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(BAF) museum is set up to showcase the glorious past of the country’s airforce. Various artifacts including the helicopters and aircrafts used in liberation war are displayed in its building and garden. WOODS This area of the airport was already covered by trees. In accordance with the goal of increasing the city’s greenery to enhance air-quality and tackle the increasing temperature, they have been kept as a little forest inside the park. The area has been made accessible through some paths to let the visitors enjoy this different land-scape.

wet conditions. PHYTOREMEDIATION The water treatment plant is designed to improve the water quality within the network, by the positive effects of plants, aquatic species and other natural elements. The water entering from the canal, will go through the 5 ponds, where pollutants and sediments are progressively reduced and it is finally reintroduced in the fishing area.

PANORAMA HILL For the construction of the park significant areas will be dug, in particular the canals, phytoremediation ponds and detention basins. Part of the terrain obtained by the excavations is used to create a panoramic hill. From this point visitors will have a spectacular view on the park and the surrounding built environment. It is also equipped with slides and stairs to be used as children playgrounds when dry.

The park, through its facilities and uses provides the possibility to do activities related to water and to spend time in a landscape characterized by water in order to foster the citizens’ relationship with this natural element. Also the “Dhaka Structure Plan 20162035” remarks the importance of spaces of this kind to bond people with water. It is believed that people who play and spend pleasant time with this natural element will treasure it even more and want to be guardians of it. This is key to ensure Dhaka’s water sustainability for the future generations.

DETENTION BASIN Three detentions basins are arranged within the park. Since its remarkable dimensions, this will give considerable detention capacity to the network to withstand heavy and prolonged rainfalls. They are covered by swamp species that can live both in dry and

The project deeply relates to Louis Kahn’s monumental Capital Complex at Sherebanglanagar, the most famous and important monument of the country which is one of the main Dhaka’s attraction for tourists. The park and the canal are directly connected to the Chandrima Udyan, the park in front of the National Parliament House. Through

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this intermediary park the new Tejgaon is connected to the Parliament House without any particular distortion of the urban layout of the area, so as not to affect the monumental heritage of the parliament. This connection between the new green-blue infrastructure and the architectural heritage, create a beneficial relation between these two important assets of the city. Also the structure plan stresses the importance of historical buildings and monuments, in Dhaka’s public space context, because of

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their recreational and educational character. Improving accessibility to the Parliament House and liking this two different attractions will provide beneficial effects for both of them. Locals and tourist will consequently enjoy an integrated and connected cityscape, that will ease their movement and leisure in the hectic central area of Dhaka. The green-blue infrastructure and Louis Kahn’s monumental Capital Complex have a deep relation not only at a functional level but also in the reasons behind their design,

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in the importance given to the natural elements and in their relation to the traditional settlements pattern based on ‘natural’ flood management schemes.. In fact the Capital Complex is set in an ensemble of water and vegetation, evoking the Bengali landscape, and similar to the green blue network, in which water bodies, in addition to addressing flooding, have been read by many as a modern interpretation of hydrological architecture which employs the traditional construction method of”dig-and-mound”: the

lake contrasting with the raised platform on which the National Assembly is built. Overall the Tejgaon park project is configured as a pilot project that could be replicated on a smaller scale in other vacant areas of the city center, such as the former tanneries area and the Old Central Jail that constitute opportunity for much needed open space in old Dhaka not to be missed.

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6 | 0CONCLUSIONS | ABSTRACT

The thesis investigates the possibility to build resilience in an urban area through green-blue infrastructure, exploring the role of natural elements as ecological resources for the city. The strategy aims to turn Dhaka into a resilient biofillic city i.e. a city able to withstand the present and future chronic stresses and acute shocks, that provides close and daily contact with nature and seek to foster an awareness of and caring for nature. The project focuses on the Core Dhaka which is the western part of the city encircled by the embankment. It is the densest area, that host millions of people and numerous facilities fundamental both for the city and the whole country, where the urban issues are most severe and actions to redress the alarming situation are urgently needed. In the eastern part of the city similar issues are diagnosed but this area is less urbanized and floods are caused by river overflow and not by waterlogging, due to the lack of the embankment. The lower density makes it possible to have wider possibilities in the eastern area for the realization of a resilient city. Of course an integration of the proposed project for the western Dhaka with a plan for the entire Dhaka Metropolitan Region would be beneficial to build resilience at a regional scale. Also in regards to waterbodies, the situation is most critical in the central densest area. In fact suburbs have been developed inte-

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grating canals and lakes in the urban fabric and actions have been taken to preserve an enhance the assets of the wider canals. But the city seems to be powerless in preserving the canal in worse conditions, which lay in the densest central area and today are about to disappear due to their encroachment. For this reason the project focuses in part on one of these canals (specifically Ramchandrapur) to make a proposal for its recovery, showing that the city does not have to give up on facing this demanding challenge. There are however some issues concerning Dhaka resilience which need to be further examined and dealt with. For instance the siltation process of the delta constantly rises riverbeds, consequently it is needed to rise the embankment, to periodically dredge the rivers surrounding Dhaka or to develop an alternative flood protection system. Additionally the complicated Bengali bureaucratic context, in which dozens of different authorities are involved in the management of these issues and the lack of coordination, makes it difficult to understand what the actual responsibilities of each organization are both in the current state and in the hypothetical realization of the actions envisaged by the strategy. For this reason the thesis, while analyzing the various levels of involvement of the different organizations, does not propose a specific administrative structure for the implemen-

Building Resilience through Green-blue infrastructures

tation of the strategy, but focuses on the design of the city and on the proposal of a new urban planning scheme. It is clear that further in-depth research by expert consultants would be necessary to find out the most adequate organizational and management form to implement this plan. The proposed masterplan is not supported by advanced water modeling and specif scenario analysis, thus it can not obviously be assumed that it will completely solve the waterlogging issue. However it shows a new way of tackling the problem, a different kind of urban design that has not been considered yet for Dhaka, but that could be effective for watermanagement and have beneficial effects on other urban spheres of the city in particular on green and public spaces and mobility. The structure plan for Dhaka 2035 shows a full awareness of the problems of the city regarding waterlogging, water supply, public space, greenery, solid waste management, pollution, traffic and public transport. Therefore, policy makers have understood the need to address these issues on which the thesis is based. Also with regard to the proposals of the plan, it is clear a desire to preserve water bodies and green spaces and to connect them. This shows that interventions of this type, on which the project is based, would be embraced by the administrators. Furthermore, the realization in Dhaka of major interventions on water bodies

like that of Hatirjheel, show that the project would be feasible. Within the structure plan, due also to its character, these hypotheses of gen-blue infrastructures remain very vague and have little importance in the general dynamics of city planning. The thesis takes the question to the next level, with a more radical proposal. The green-blue network becomes the main element of this strategic master plan, modifies the urban landscape and constitutes an integrated solution to different problems of this dense megacity. The recovery of the existing canals, the re-opening of the former ones and the design of detention and infiltration area, give to this idea of a green-blue network, which is only mentioned by the structure plan, a spatial arrangement within the urban fabric. Overall, the thesis proposes an environmental sensitive urban planning centered on water and highlights the importance of natural elements as ecological resources within a dense urban context, an approach that could be beneficially adopted in other cities to improve the life quality of their inhabitants.

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7 | BIBLIOGRAPHY AND CREDITS 0 | ABSTRACT

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Sciences and Technologies for Security Applications)”. Springer International publishing Switzerland. Zakir Hussain, A.M. (December 2018). “Inadequacies and Failures of Government Strategies and Policies in Solving the Problems of Flood, Waterlogging and Landslide”. Floods Waterlogging and Landslides in Bangladesh. Dhaka: Bangladesh Environment Movement (BAPA); Bangladesh Environment Network (BEN). 180-191. PLANS AND PROJECTS Dasgupta, S.; Zaman, A.; Roy, S.; Huq, M.; Jahan, S.; Nishat. A. (2015). “Urban Flooding of Greater Dhaka in a Changing Climate: Building Local Resilience to Disaster Risk. Directions in Development.” Washington, DC: World Bank.

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Mahmud, A.H. (12 September 2017). “The sorry state of Dhaka city canals”. Dhaka Tribune. Retrived from https://www.dhakatribune.com/bangladesh/dhaka/2017/09/12/sorry-state-dhaka-city-canals/

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Mahmun, S. (30 April 2018). “Waterlogging in Dhaka: Lack of coordination among authorities to blame”. Dhaka Tribune. Retrived from https://www.dhakatribune.com/bangladesh/dhaka/2018/04/30/waterlogging-dhaka-lack-coordination-among-authorities-blame Mariani, Luisana. (n.d.). “Urban Resilience Hub”. Retrieved from http://urbanresiliencehub.org. Mayor of London. (February 2008). “East London Green Grid Framework London Plan (Consolidated with Alterations since 2004). Supplementary Planning Guidance”. Retrieved from http://www.queenelizabetholympicpark.co.uk/-/media/lldc/local-plan/local-plan-examination-documents/regional-planning-policy-documents/rp9-spgeastlongreengrid.ashx?la=en 1234r5ty678i9

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Mayor of London. (March 2012). “Green Infrastructure And Open Environments: The All London Green Grid. Supplementary Planning Guidance” Retrieved from https://www.london.gov. uk/sites/default/files/algg_spg_mar2012.pdf

Zakir Hossain Chief Executive of “Nagorik Uddyog” (The Citizen’s Initiative), NGO for people’s participation and access to democracy rights, justice and development

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Engr. Md. Sharif Uddin Superintending Engineer (Civil Circle) & Project Director, Dhaka North City Corporation.

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Prof. Dr. A.K.M. Saiful Islam Professor at Institute of Water and Flood Management (IWFM) at Bangladesh University of Engineering and Technology.

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Prof. Dr. Mahbuba Nasreen Director and Professor of Institute of Disaster Management and Vulnerability Studies (IDMWS), former professor at Department of Sociology, University of Dhaka.

credits Prof. Dr. Qazi Azizul Mowla, co-supervisor Professor and former Head of the Department of Architecture at Bangladesh University of Engineering and Technology, teaches at Undergraduate , Master’s and Doctoral Programs on Architecture, Urban Design, Architectural Conservation, Built-Environment Design and Regional Planning. He has more than 125 professional publications in refereed journals or proceedings, has taken part and/or organized national and international seminars/workshop/ conferences and juries and he is a curriculum consultant and pubblications reviewer for many University in Bangladesh. He has always been committed to the themes of nature and ecology in their relations with the built environment, is one of the most renown voices on Urban Design in Bangladesh and expert of Dhaka town planning.

Shibu Prasad Bosu phd candidate at Department of Architecture, Bangladesh University of Engineering and Technology.

Arch. Md. Iqbal Habib, co-supervisor Iqbal Habib is among the most known environmental activists and architects of the country. He is the Joint Secretary of ‘Bangladesh Environment Movement’, active organiser and a public voice of some of the pressing environmental and urban issues. He is the Managing Director and one of the principal architects of the award winning architectural firm VITTI Sthapati Brindo Ltd. that designed Hatirjheel–Begunbari Integrated Development Project, Dhanmondi Lake Development Project, Asian University for Women (Local consultant), HQ of the Institute of Architects Bangladesh etc. Iqbal Habib comes with some new ideas of breaking barriers in Dhaka’s urban issues and housing problems.

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Arch. Nabila Aftab Senior Architect at VITTI Sthapati Brindo Ltd Prof. Dr. Md. Mozammel Hoque Professor at Department of Archaeology, Jahangirnagar University Prof. Muhammad Nurul Kabir Bhuiyan Assistant Professor, Department of Archaeology, Jahangirnagar University Prof. Mesbah Kamal Professor at Department of History, University of Dhaka

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8 | Acknowledgments 0 | ABSTRACT

Thanks to Romeo Farinella for believing in this project since it was a blurry idea in our mind and for having accompanied us to its completion. Thanks to Elena Dorato for her lucid advice, honesty, helpfulness and kindness Thanks to Qazi Azizul Mowla for giving us the opportunity to immerse ourselves in this fascinating urban context, both on field and in the academic world. Thanks to Md. Iqbal Habib for the time devoted to us and for having shared with us his unparalleled direct work experience in urban and landscape planning of water bodies in Dhaka City.

With professor Qazi Azizul Mowla, at Bangladesh University of Engineering and Technology, Department of Architecutre, Dhaka

Thanks to Zakir Hossain for being our wingman in Dhaka, for the help, the valuable advice, the networking and the material supplied to us. Thanks to Shibu Prasad Bosu and Nabila Aftab for supporting and guiding us. Thank to Md. Sharif Uddin, A.K.M. Saiful Islam, Mahbuba Nasreen, Md. Mozammel Hoque, Muhammad Nurul Kabir Bhuiyan, Mesbah Kamal for the will to help us that you have proved, the advice, the help, the encouragement and for sharing with us your precious knowledge. Thanks to Bangladesh and its People for their generosity, 252

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With architect Md. Iqbal Habib, at VITTI Sthapati Brindo Ltd. architectural firm offices, Dhaka

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8 | 0Attachments | ABSTRACT