Rural stocks and flows - urban metabolism in small cities, the case of Dannisa, Ethiopia by Tanja Potezica

rural development

ethiopia

rural development

ethiopia

project for „rural stocks and flows urban metabolism in small cities“ the case of dannisa, ethiopia summer semester 2017 bauhaus-university weimar master in european urban studies & advanced urbanism baskazanci, ceren hajdu, marcell nilsson, johan potezica, tanja

content

introduction 1.1 background and problems 1.2 scope of the project 2. dannisa today 3. job opportunities and sectors 4.1 establishing concepts 4.2 spatial development model 5.1 water 5.2 phasing of development 6.1 building typologies 6.2 typologies and constructions 6.3 materials 7.1 computation analysis model 7.2 criteria for development 7.3 scenarios and land-use maps 8. personal reflection references and acknowledgements

4 8 9 12 18 24 26 30 33 38 39 41 48 49 50 62 66

Ethiopia‘s government is going ahead with a wide domestic plan for what they call „Rural Urban Development Centres“ (RDCs). The plan is to develop around 10 000 rural settlements across the country, during a 5-year period. Right now, the project is in its „sketching phase“. What is this plan about? It is a way to cluster the rural areas, in an attempt to optimise the land use and also slow down the direct migration from the rural to the urban, in a country where around

85% still live in the rural areas. According to the government there are a few variables to be met for an area to be called urban, one being it has to at least hold 5000 inhabitants. The future idea is for many of these RDCs to evolve into urban towns, whereas many of them now have less than 1000 inhabitants, a vast majority working as farmers. This project is made by first year master students at the Bauhaus University in Weimar, studying (European/Advanced)

Urban Studies. This part followed an initial project analysing urban metabolism in the small towns of rural Thuringia (state in Germany). The project was developed with the background of an understanding of the urban development as a metabolic system. The spatial modelling and analysis has been made with support of computational analyses through Rhino and Grasshopper.

1.1

project background and problems

Our aim is to discuss critical issues of rural development in Ethiopia, as an initial piece of a larger picture of problems facing the country. The overarching questions we are dealing with are;

Which resources are needed for a growing town? What does it mean for growth and where are the limits for a balanced development/planning model?

It is essential that we consider what are “highpriority interventions” in initial phases of development, what are the catalysts (incentives) for enabling human activity and possibilities for prosperity? Can we build up an understanding of potential (both undesirable and aspired) consequences.

Which are the pillars we can focus on, and what are the goals of these? And as far as we can model and conclude on, without behind unreasonably speculative; how are the pillars influencing the future physical environment, spatial ordering and taking care of the natural environment?

1.2

scope of the project

Migration to urban informality The migration to urban areas from the rural land is a way for many to search for improvement of their lives with more job opportunities, broader social networks, services and connections and improved living conditions. The vast urban informality should and needs to be understood as a logical response to insufficient social services or possibilities in the formal sector for housing, healthcare, jobs or other institutions supporting migrants. Legitimising a plan In order for any plan to be legitimate it needs to present solutions based on a consideration of local needs and gain approval from the community. There is therefore a need

to create a framework for a collectivised progress and development, which enables the community to back, support and build up their own progress. There is no ideal plan, nor any ideal “sustainable” solutions. But there are potentials for humancentred plans which are based on knowledge in regard to physical development, past experiences and their lived and studied consequences. Both in regard to social and technical systems. One grand question is how to keep on track with the goals of lowering poverty and raising the resilient structures for a town to keep its citizens occupied, safe, and enabling them to better their living standards, not leaving people without any choice rather than migrating to urban areas (Dorosh. P & Schmidt. E 2010, p12).

This is what this catalogue seeks out to do; presenting lessons learned when facing issues of spatial planning and design, and what parameters could indicate starting points for the Rural Development Centres (RDCs). It also seeks to combine spatial planning with the consideration of „urban metabolism“ as an important concept to follow flows of components (water, materials, goods etc), their inputs and their outputs (waste) as an indicator of a plan’s environmental impact. The efforts to create prospering communities will find its priorities through the core idea of critically and pragmatically digging into questions and problems raised on a regional-, rural-, and local scale in Ethiopia.

dannisa today

Dannisa is a small community of around 900 inhabitants, almost all of them occupied in the agriculture sector as farmers. It is located in the large Oromia region, ~125 kilometers west from the capital Addis Ababa. It lies in the Dega climatic zone (the cool zone), above 2440 metres in elevation with an average annual temperature of about 16˚ with annual rainfall between 1270

and 1280 millimetres. These conditions make agriculture and living overall very favourable.

today in the town, but a few motorbikes.

The settlement is not very well connected considering mobility. As the map below shows, it is roughly three hours walk to Ginchi, the biggest town in close connection but today there is no public transportation linking them, and there are no reported cars/trucks

regional map around Dannisa, with Addis Ababa ~125 km to the east. many still walk to Ginchi (3 hours) for most services.

thodox

mers

protestant

production

people and culture

barley

people and culture

potatoes oromian

amharic

ekalyptus orthodox

protestant

oromian

amharic

orthodox

protestant

araki

production production

potatoes

barley elevation 2805 meters potatoes

ekalyptus

barley

farmers

araki

farmers

araki

people and culture oromian

amharic

orthodox

protestant

production barley potatoes ekalyptus farmers satellite image of Dannisa

araki 15

AGRICULTURAL LAND

WATER PUMP

job opportunities and sectors

With a huge demographic potential in Ethiopia, there is a need to create sufficient and stable jobs to absorb the growing labour force. Most of the inhabitants rely on agriculture, directly or indirectly, as their source of income and occupation (80-85% of the population). The country will have to focus on a shift from rural farming to labour-intensive largeand small-scale industries such as agro-processing, light manufacturing and along it a growing service sector.

The potential of agriculture 65% of all uncultivated arable land in the world is located in Africa which has the potential to not only feed the continent, but also an estimated nine billion people in 2050 (Adesina, 2017). Thus, this potential source of farming could lead to create a revenue channel in agro-processing industry. In developed countries, 98% of agricultural production undergoes industrial processing, while for the developing countries it only amounts to 30% (UNIDO). For these countries, agro-processing industries generate 60% of

manufacturing value and agro-industrial products account for almost 50% of the total export value (UNIDO). Learning from the region In spite of the definite amount of labour and seasonality dependence in agriculture, after harvest the processing industry can attract a large workforce thus creating jobs for the job-seekers and unemployed. For example, Rwanda increased the percentage of national budget dedicated to the agriculture industry, which lead to the creation of 430 000 jobs between 2000 and 2010 (Golooba, 2014). This amounted to 30% of the total job creation during that period, the largest portion of any sector (ibid.). In Mozambique, the agriculture sector provides income for 75% of the inhabitants and each year generates an additional 20 000 jobs, 6% of total jobs annually created (Franco, 2014).

Why agro-processing industry?

Manufacturing in Ethiopia Manufacturing is also a key pillar of Ethiopia’s economy. The 2008 Survey showed that 50% of the manufacturing establishments were micro-scale enterprises employing less than ten people (Gebreeyesus, 2016). In 2002, 87% of the total employment in manufacturing engaged in cottage/handicraft. The manufacturing industry composition is mainly consisting of micro and small-scale manufacturing enterprises. In the smallscale manufacturing the grain mill sector is the dominant one in terms of number of people, employing 50% of the total work force (ibid.). Medium- and large-scale manufacturing industries are characterized by a limited range of light manufacturing activities such as food and beverage, textile, leather, non-metallic, and furniture.

In 2010 among the mentioned industries, food and beverage were the businesses employing the most (ibid.). Learning from rural Germany Regarding the industries in Thuringia, the main driver of growth for employment are regional activities of small and medium-scale enterprises. Micro and small-scale enterprises represent the vast majority among companies. 80% of the

96 000 companies have less than nine employees (Industry Benchmarks, 2017). With the focus on dynamic and futureoriented growth in policies, many industries expect a great expansion in job creation until 2020. Large agricultural sectors could provide export revenue from diversified high-value-added processed products in different agro-processing industries such as the ones mentioned earlier.

Job opportunities in manufacturing

Beyond agro-processing industry and light manufacturing, the service sector will accelerate strong employment growth in the future characterized by a limited range of light manufacturing activities such as food and beverage, textile, leather, non-metallic, and furniture. In 2010 among the mentioned industries, food and beverage were the businesses employing the most (ibid.).

Transferring previous notions to the spatial development of Dannisa What we can take from this knowledge and the examples is that the potential in various sectors can give us indicators of how the economy can diversify. This diversification of job opportunities are essentially economical drivers that push development of the rural into a more complex spatial structure, and asks questions of how a town

grows (population and thus jobs), and what it grows into with a higher variety of functions interacting with each other. As a spatial reference point (graph below), Waltershausen (population; 11 000) in Thuringia employs 1900 in the industrial sector which amounts to ~14% of the total spatial area. The city also has the highest percentage allocated for housing among the analysed rural

cities (34%). For Dannisa, the development has to consider the incorporation and establishment of sectors that are today absent. But even in the unlikely case a large-scale industry develops here, housing will arguably still take up the largest part of the town.

Industry in Thuringia

4.1

establishing concepts

The process leading to the concepts The process derived from basic but critical questions aiming at what are essential needs for the inhabitants, which sectors we can foresee jobs in, and how these result in spatial and physical development concepts. In the pursuit of answering these questions with a focus on the local situation, water was set out to have a big potential, with ideas about distribution already discussed in Dannisa. We also pursued in creating a pillar that could be connected with material usages, jobs, trade, with physical development and also the direct needs of people. The building sector is one slightly pushed aside with focus often set on agriculture and industry, but an area we argue to be highly connected with the above mentioned criteria.

The idea of looking into these two pillars is not to exclude any else, nor have we neglected the importance of aspects such as agriculture, energy, industrial land and many more. But this project, and these two pillars, will present their high impact on any spatial and physical development. No urban overspill Mike Davis (2017), speaks of the unnecessary, and frankly dangerous consequences of land grabbing and the “urban overspill“, that builds up arable land. This happens, for one, by not supporting communities with the right planning tools. Davis speaks of this in very urbanised cities, but the rural area must consider the agriculture land as open space, an inherited landscape which is in need of a perspective on its preservation and heritage.

Detailed interventions, no master plan The idea of a final blueprint land-use plan is long overdue. The concepts need to be built upon as the project moves on, but with more detailed interventions of “acupuncture” measures into development. Intervening on a detailed level can in a more satisfying way see consequences of development further ahead, giving better insights to what issues may arise and how to tackle them. Then one might say that the overall image of a settlement is left out for too much uncertainty, if there is no overall image. We argue, that the overall image is the one creating speculation, allowing for misinterpretation of what stages, phases and aspects come after each other. Some pieces of a city are only stemmed and put into motion when a certain component is put in before.

what are the initial needs/catalysers for development?

ENERGY

WATER wells pumps

tele

wind

pipes

INFRASTRUCTURE

water solar

roads

pipes

rails

these aspects shape the spatial structure

where are the main job opportunities?

industry/ production manufacturing

building sector

what is the relation/ conflict between them?

construction materials building typologies

agriculture agro-business

food

these aspects dictate (policies for) zoning and land-usages

HOW DO THESE PILLARS AFFECT SPATIAL DEVELOPMENT?

WHAT ARE THEIR POSSIBILITIES? THEIR LIMITS AND CONSTRAINTS?

4.2

spatial development model

Water For any concepts to be legitimate they must align and interact at different scales with other components. In this

larger scale

lower scale

sense, water will be the overarching pillar in which the spatial development will “find” its limits, possibility and subsequent form. The importance of water is discussed on

WATER

BUILDING TYPOLOGIES

CONSTRUCTION

previous page, and more in detail in chapter 5. Building typology What is the first question we need to address when land is allocated? - What buildings can and should be built, how and with what materials can this be done. Therefore it is essential for the physical landscape that the various building typologies are understood and set. It is the formation of shelter, of business, an enabler for social activities and also its typology sets how dense an area is, and (possibly) how much activities can take place on the land.

MATERIALS

THE FLOW OF THESE COMPONENTS... ....will build up an understanding of the metabolism for the town

by showing their origin, physical impact, systems and waste products

Connecting components On the highest scale there is the water supplied area which gives the land that can be developed. This land is though limited by the agricultural land, which should be preserved as far as possible, and the inaccessible wetlands. Going further down in scale the typologies sets

the density and allows for different functions. In relation to the required road and street networks, as well as the relation of open and built space develops. The lowest scale indicates which constructions and materials can be used for the certain typologies.

Above all stand economic, social and environmental aspects which shape the development and relation between the components.

SECURING WATER SUPPLY

5.1

water

Water as important and valuable resource Water is the most valuable and necessary resource in cities. The lack of improved drinking water supply and sanitation threatens communities with manifold crises. Economic disadvantages, health issues, disempowerment of women and lacking education for children can all be overcome by providing sufficient water access to communities. (water. org) According to UNHabitat, today still 11% of the world’s population lacks access to safe drinking water, and in the case of Sub-Saharan African countries this figure rises to around

40%. At the same time the lack of proper sanitation leads to the contamination of available water resources with the growth of population and the densification of settlements. (UN-Habitat) Along this line of thought we chose to provide the RDC of Dannisa with a development scenario partly based on the sufficient and costeffective provision of drinking water, taking into consideration future growth possibilities. WHO guidelines set the minimum amount of water to satisfy the very basic needs of an individual at 20 litres a day. This amount still leads to health concerns,

thus the recommended minimum water supply per person is 50 litres (WHO). It is also important to take into account the future developments in the field of sanitation. In case of using flushing toilets, the water demand doubles. These quantities vary according to climate zones, level of development, hygiene awareness, etc. There are different stages of providing people with access to water. Currently the drinking water in Dannisa is supplied through mechanical pumps, without any sort of distribution system. With the growing demand and the development of the settlement the instalment

WATER SYSTEM Max. 40m

of industrial pumps and later the development of a distribution system will be inevitable. Most distant users should be around 200 meters from available access points, but in the case of not so densely populated rural areas 500 meters are sufficient. One tap should be able to supply 40-70 people, but access points with multiple standing pipes can be enough for 250-300 people. (Lenntech) The organization and surveillance of the water supply is an important issue to be solved by the community, in order

to prevent the wasting of water. This is done through the gating of access points and establishment of a price for the water. In later phases as access becomes more individual, the calculation of prices has to be based on the measured amounts of used water.

Drinking water supply In the case of Dannisa the main source of drinking water has to be groundwater. Apart from the already existing mechanical pump, others

have to be built, to explore the underground water reservoirs (150-200m under surface level). As the most expensive part of the water supply system is the well, geological surveys need to be made previously, to locate the best possibilities. The use of gravity water supply systems in developing countries and smaller communities is advantageous for many reasons. Firstly as it is moving water with the help of gravity, no additional pumping is needed, which is an important cut in the costs

of the system. Secondly due to the very low amount of moving parts in the system the needed maintenance is minimal. Thirdly the pressure inside the delivery system is easily controlled, making it more reliable. These systems can supply water to a large number of people at relatively low costs, making them optimal for cooperative community developments. (Arnalich, 2010) In order to have sufficient pressure to supply the houses of Dannisa with drinking water in the future the new pumps and reservoirs have to be located above the settlement’s level. The height difference between the reservoir and the serviced area optimally has to be between -6 and -40 meters. The distance of the piping isn’t strongly influencing the serviced area, because the height difference provides sufficient pressure to transport water for big distances. The size of the required tank is defined by the maximum water demand of a day. It is changing according to the population of the city and the daily routines of the residents. As

the construction of the reservoirs also is one of the most costly parts of developing such a system, it is better to plan ahead the predicted population growth. In case more than one wells are developed, the size of the reservoirs has to be divided according to the demands. If calculating for 10 000 people, a reservoir of 12 meters in diameter and 3 meters high would be sufficient, to cover the 50 litres per person per day demand. As mentioned in the case of implementing flushing toilets, this demand would double, creating a need for bigger reservoirs. Regarding the distribution system, the use of looped piping is recommended as it is reliable and in case of disturbances in one section still can provide every access point with water.

5.2

phasing of development

The development of the drinking water supply system happens parallel with the growth of the settlement. In the initial growth phase new wells are created and the water is pumped mechanically. With the development of the energy infrastructure more effective pumping machinery can be installed, which later can provide the growing

population with sufficient drinking water. No piping is built in this phase, residents use the access points at the wells. Later on, access points are created in the most dense areas, according to the previously mentioned specifications. Access point are gated to prevent wasting and are only open for certain time periods

during the day. The residents if the town only have to walk a short way for drinking water, which already leads to improved conditions and opens up newer development opportunities. As the town expands according to its population growth, new access points need to be opened, which require the development

PHASE 1 WELLS AT WALKING DISTANCE

PHASE 2 PROVISION OF ACCESS POINTS

PHASE 3 PROVISION OF PIPES

of the distribution system (piping). Pipes are installed underneath transport pathways, under commonly owned land. With the multiplication of available taps, loops are closed in the pipe system, making the system more safe and reliable.

pressure inside the system. Slopes have to be taken into consideration as well, to avoid high and low points in the system. At low point sediments tend to collect, at high points air bubbles may be trapped, leading to serious water hammer effects.

In the long run, the established water supply system is sufficient to provide all households with individual drinking water access. Still, it is important to take it into consideration, that in case of using improved sanitation the water demand doubles. At the same time a need for the treatment of sewage appears, which requires a relatively expensive infrastructure.

In the lower area of the town an extensive wetland is located. This area is off limits for building, because of the strong floods during rainy season. At the same time it provides the city with a great opportunity to build large reservoirs here to collect rainwater in order to extend productivity in agriculture into the dry season. Existing agricultural lands could be more intensively used. According to that the development scenario provides spatial plans preserving existing agricultural land.

What are the limits of spatial developments according to water supply possibilities? Topography plays the most important role in the water related limits of Dannisa’s spatial development. As mentioned, water reservoirs supplying the future distribution system need to be located above the serviced area, but this difference has to be between 6 and 40 meters, to provide suitable

The centrality of this location enables the use of collected water for any industry necessitating water, especially in case these industries develop in the northern areas of the town. A good example for that would be the processing of potatoes as one of the most prevalent agricultural products of the area.

6.1

building sector

typologies

materials

construction

.amount needed .costs .availability .transportation .environmental impact .health aspects .durability

knowledge .knowledge provided and developed for different constructions

labour spatial character

.skills needed for more complex constructions

social acceptance

functions .residential .administration, commerce, residence, service, and other compatible uses services .manufactoring .recreation .roads

.open space .heterogeneity of town pattern .identity of a neighbourhood

The building sector is one of the main resource consuming components in the metabolism of the built environment and has one of the biggest impacts on the economy, people and natural environment. As the housing demand is steadily growing, a sustainable solution for the construction of residential building has to be found, in order to ensure the future of rural

urban developments. In order to understand the building sector and its spatial impact, we divided it into three main components: typologies, construction and materials. The relation between these three components is important to understand in order to provide a sustainable concept for the future development of the building sector.

The basis of the development is the relation of the built and open space of a plot. The typology affects the land needed if a certain open space is demanded. Further on it affects the construction which is needed and the amount and type of materials.

6.2

typologies and constructions

Which typologies and constructions are feasible and align with the lifestyle of the local people?

changing due to these parameters.

Based on the existing settlement pattern and the norms and standards given by the Office for the Revision of Addis Ababa Master Plan (2002), for the development of the residential buildings in Dannisa, we decided to examine attached and detached houses - one storey, two storey and three storey high.

Detached houses

The important parameters were: open space ratio (OSR), plot size and the density resulting from the household size and the housing area. For our calculation the open space ratio was fixed according to the typology (attached: 45, detached: 35, existing typology: 15, for each additional storey additional 5), we calculated with households of five with a housing floor area of 70sqm.. The plot size is

The detached houses would align with the existing settlement pattern, giving a similar rural character and serving the rural lifestyle in its current state. Yet the density is not sufficient if the town is to grow up to 10 000 inhabitants and still preserve as much agricultural land as possible. From the economic side, the amount of materials is 10 - 20% higher than for an attached housing typology. Therefore requiring more resource consumption and higher costs.

Attached houses The attached housing typology, like the row house, would mean a new

spatial character in the rural areas. Typologies like these are already emerging alternatively to big, multi-storey condominiums within the Grand Housing Program (GHP) in areas in and around Addis Ababa. We perceive this typology as a suitable development for Dannisa, as it is the middle way between the existing typology and big housing developments implemented by the government. The attached typology is serving the needed density for the growth of the city, whilst maintaining the private plots of the inhabitants. Due to the back and front yard, there is a distinct separation between levels of privacy, providing public, semi-public and private areas. As many activities, like cooking, eating and gathering happens in the garden, the fixed OSR gives enough open space for keeping up this tradition. Never the less, the social acceptance could be a limiting factor in the

development. From the economical aspect, this typology is less material consuming and therefore less cost intensive. Further on it enables mixed use as there is clear back and front of the building, giving space to commercial/small manufacturing use in the front. All together, we perceive the attached typology as very suitable for rural urban developments, not only in economic and environmental sense, but also in a social one. Still we believe that there has to be balance between attached and detached typologies to ensure heterogeneity and different identities within the town.

Multiple storeys Looking at multiple storey constructions, these would deliver a higher urban character and more easily enable mixed use settlements. The higher density would also ensure a more efficient land use, using up less land which is needed for agriculture and other functions.

The biggest limit is though the advanced construction where knowledge and skilled labour is needed. Here we see the opportunity for the community, together with the existing educational institutions, to develop and teach these skills. Along this development a new economic sector could emerge, providing new job opportunities.

6.3

materials

When it comes to sustainable housing development, the choice of materials plays a crucial role. They have to be low-cost or affordable in order to keep on track with the goals of lowering poverty (Donath, 2012). Further on, the environmental and human health impact has to be considered; before, during as well as after the lifetime of the building. So it is crucial to develop strategies in material choice to ensure a sustainable rural urban development.

Which materials are available? What can houses be built from? In Ethiopia, the main resources for building materials are stone, timber and clay. Currently the main building material used in Dannisa is eucalyptus, combined with straw and clay. For future growth of the town, there has to be an alternative, as an extensive use of timber for building construction

leads to deforestation and land erosion. This issue is especially causing problems in agriculture, threatening food production and intensifying food scarcity. (Afkari, 2002) Stone Stone has always been one of the main materials for construction. Ethiopia, especially in the central part has extensive resources which have been already used in vernacular

housing constructions. Especially in the 1990’s many building stone deposits have been established. There is high potential of stone resources in central and southern Ethiopia which could ensure a low-cost and environmental friendly building construction in rural urban developments. When it comes to affordable housing construction a crucial point is the processing of the rocks; it has to

be feasible with simple technology and low cost. As soft rocks are preferred for such uses, basalt, tuff, ignimbrite and sandstone are the mainly used types. (Walle, Zewde, Heldal, 2000) Looking at Dannisa, as it is situated in the central part of the country, the use of stone would has good potential due to the proximity to the existing deposits. In later developments, there is also a potential of new deposits in the surrounding and an own production of the building material. These two opportunities would easily enable a town growth up to 10 000 inhabitants. Clay Clay based materials have good properties and sufficient resources in the context of Ethiopia. Still, the clay building material industry is small comparing to concrete and cement industry. Therefore the current building constructions in Ethiopia are based on hollow concrete blocks (HCB). Looking at Thuringia small towns, most of the housing construction is done in bricks as it has better properties than concrete and as well an established industry. Could

this be a sustainable option for Ethiopian rural urban developments? When comparing the two materials we looked at the following aspects: required amount, costs, availability, transportation, environmental impact, health aspects, durability and recycling. In conclusion bricks are more environmental friendly and provide a healthier indoor climate than concrete. But in current state the limitation of the undeveloped production is the main factor for the choice of HCB blocks. At the same time it could be an opportunity for new job and industry creation. A limiting factor in both cases is the cost intensive and tied to big industries production. Additionally a sufficient transportation connection is required.

Which alternatives are there beyond commonly used building materials? In the past years alternatives are being researched and developed in academia: projects like the SUDU (Sustainable Urban Dwelling Unit), SICU

(Sustainable Incremental Construction Unit) , MACU (Mobile Automated Contemporary Unit) or SECU (Sustainable Emerging Cities Unit). All these projects are aiming for constructions from affordable and recyclable elements with standardised systems. These approaches are very welcomed by the Ethiopian government and other organisations. Further on they are giving the foundation for alternatives to standardised concrete mass housing developments.

What are the possibilities for Dannisa? For the town of Dannisa, as agriculture is the main production sector, we see a possibility in materials production which is tied to it. Materials which are produced out of agricultural leftovers, like the agrostone or straw panels, could pose a possibility for the building construction materials. Agrostone is a composition of agricultural and/or industrial waste, lightweight minerals (fillers), magnesium-based chemicals (binder) and fibreglass (reinforcement).

total usable space exterior wall size interior wall size

TYPOLOGY EXAMPLE

+ HOLLOW CONCRETE BLOCKS cost of walls 91.500 birr +plastering 97.500 birr

BRICKS

cost of walls 66.825 birr + plastering 97.500 birr

STRAW PANELS

cost of walls 123.000 birr + connectors and glues 20.000 birr

70m2 120m2 165m2

established market easy production no advanced construction skills required

high costs due to high cement usage dependancy on cement high water consumption low indoor climate

environmental friendly, breathable and good insulation healthy material, due natural origin low impact on environment no advanced construction skills required

high production costs complicated production

low cost environmental friendly, breathable and good insulation natural origin and high percentage of reused ingredients low impact on environment no advanced construction skills required easy production, also on local scale

no industrialised production and supply

As cement is not needed, the costs can be held low and most of the ingredients can be found locally. Additionally the production does not require expensive and big machinery. (Taffese, 2012) Straw panels are an environmentally friendly, healthy, low-cost and easy in construction. Industrialised production is already existing in Rwanda and it is recognised as a functioning construction material. As the production technology is developed to be easy to manage by small local manufacturing, it gives an opportunity for reusing the agricultural waste in Dannisa. (Strawtec, 2015) If we look at the building sector in a symbiotic way, connecting it with other components like agriculture, water and industry, a holistic concept can provide efficiency by maximising the use of resources. As affordable housing is needed, we see an opportunity in developing alternative materials in the educational institutions, which are then made of locally available materials and in a local production (see chart to the right).

Still, currently concrete constructions will be preferred as alternatives are not established or enough proven to function. Yet, we think there is good base for further development and therefore a chance for a sustainable construction development in rural urban growth.

low water consuming production and construction

jobs

water

input

transportation

materials

research on new materials

education

usage of agricultural waste

agriculture

manufacturing of materials

output

industry

7.1

computational analysis model

The model with Rhino and Grasshopper To overcome the difficulties of planning without having the opportunity to explore the physical environment, and to accurately connect the research on typologies, water supply systems and possible economic development scenarios we had built various computational models. The physical models were built in Rhino and further developed/analysed with Grasshopper. Firstly we analysed the topography of the settlement, showing the height differences and the slopes. The first important model regarding the drinking water supply system was based on this data. As mentioned in the previous chapter dealing with the gravity water supply system, the reservoirs supplying water to the town have to be installed minimum 6 and maximum 40 meters above the serviced area. Avoiding low and high

points in the distribution system are also important for a reliable supply. After locating the highest areas still enabling sufficient connections to the lowest lying buildings we have located the optimal zones for creating the reservoirs. Using these points as inputs we calculated the maximum area which can be covered by a water distribution system based on gravity. In addition to that we added the areas used for agriculture and the central, un-buildable wetland to the model as further restrictions for building activities. We separated the area of the existing settlement and surrounding areas into numerous blocks (firstly in a 50 meter wide corridor along the main roads), to individually evaluate what functions may be located in them through the different phases of development. Another model was made to calculate the plot size, open space and site

occupancy ratio (SOR) for different building typologies and numbers of storeys. In addition to this an estimation can be done for the total size of the area occupied by residential buildings and lots belonging to them as well as the total open space. We calculated with 5 person households of 70 square meters. Connecting the model which shows the spatial limitations, the analysed blocks and the typology related calculations gave us the exact number of dwellings for each block, with all the previous considerations included. This helped us to accurately predict the possible spatial development and population growth for all three phases. The most important outcome are the land use maps describing the distribution of functions and the diversity of typologies inside the settlement.

7.2

criteria for development

whenwhen the the town towngrows... grows... what what

SHOULD SHOULD

? ? WHATNOT NOT

it develop around/along, and and WHAT it develop around/along,

Current buildings remain intact in initial phases

Current buildings remain intact in initial phases Possible to distribute water pipes to all blocks

Possible to distribute water pipes topoints all blocks Set out social functions as reference for the spatial grid Build on open spaces within current settlement Set out social functions as reference points for the spatial grid along the road(s)current - initial buffer of 50 meters Build Developing on open spaces within settlement

Developing along the road(s) - initial buffer of 50 meters

No land grabbing - agriculture land to remain in initial phases No development in direct connection with health centre and school

No land grabbing - inagriculture land to to wetlands remain in initial phases No exploitation direct connection Consider topography - Noconnection buildings on with the steepest (slopes) No development in direct healthareas centre and school

No exploitation in direct connection to wetlands Consider topography - No buildings on the steepest areas (slopes)

7.3

scenarios and land-use maps

Criteria leading to scenarios When considering different development scenarios we concluded that the growth of the RDC of Dannisa will be more bound to the economic opportunities it offers for people moving in, as to different spatial and structural possibilities. In

the absence of sufficient drivers for economic and thus population growth, the development may stagnate at one point. Accordingly, we identified three different growth phases, along the variety of attracting economic activities and evaluated the possible spatial development scenarios. The three stages of

possible water distribution with two water sources

growth are set as; the “Slow Growth” phase (1), “Diversification” (2) and “Specialisation” (3). Lastly results also show how Dannisa could grow when agriculture land relocates and allow for higher exploitation. Details follow on next pages.

agriculture land in green and wetlands in blue. All of these areas form limits for spatial development in initial phases of development.

topography with lowlands in green, steeper areas in orange and highest points in red. The red areas are un-buildable.

SCENARIO 1 - SLOW GROWTH

The necessary infrastructure is being built and established; a bus line to Ginchi, the roads are being paved and reinforced, the water basins are built and electricity reaches all households. People moving here are mostly farmers, with main attraction points being available arable land, services, improved infrastructure and connections to bigger cities. Most would naturally settle along the well situated road, and small businesses are

established, but slowly. Population: Growth of 485 people (54% increase) to 1385. Typology: Same as existing typology and additionally detached single storey, with a higher density. +97 new houses

Legend housing commercial public institutions manufacturing attached, three storey, OSR 50 attached, double storey, OSR 45 attached, single storey, OSR 45 detached, double storey, OSR 40 detached, single storey, OSR 35 detached, single storey, OSR 15

SCENARIO 2 - DIVERSIFICATION

The school and health centre grows in numbers and sections, attracting not only pupils from around but families to move in and start their own businesses. The economy is diversifying, with a lot of land available for constructing housing. The road system is rapidly growing with improved parallel streets between markets, administrative buildings and manufacturing functions to the main road. Here, many interested in commercial

opportunities open up businesses connected with their living space. We can start to identify a diverse set of functions along the main road, and more developers raising twostorey attached housing with shops and services on the ground floor facing the street. Small manufacturing businesses develops in various locations, and those seeking to specialise later on look out for larger plots, a street or two away from the main road.

Population: Growth of 3080 people (216% increase) to 4465. Typology: Attached single storey, detached double storey and a in some areas already signs of more dense attached double storey typologies. +616 new houses Land use manufacturing 8199sqm. public institution 4120sqm. commercial 6139sqm.

SCENARIO 3 - SPECIALISATION

Industrial and manufacturing activities further develop, and in some cases specialize, taking up larger areas. The population steadily grows, at a lower rate than in the previous scenario, some areas are densified, new housing is built. Infrastructure develops accordingly. Commercial uses take up more space in the central areas. Population: Growth of 4250 people (95% increase) to 8715.

Typology: Mostly higher density two storey attached typology, one storey buildings in steeper areas. +850 new houses Land use manufacturing 72948sqm. public institution 5120sqm. commercial 11507sqm.

POST SCENARIO

In case the settlement develops further, the building of new housing is only possible by taking existing agricultural land. The most appropriate areas for that are the plots located centrally around the wetland. Further growth is only possible by exploiting more agricultural land, possibly affecting related production and manufacturing, thus endangering the metabolism of the city.

Population: Growth of 3940 people (45% increase) to 12 655. Typology: Typologies: Central block with two storey attached typology, other two blocks one storey attached. +788 new houses

HEIGHT OF BLOCKS INDICATING THE PERCENTAGE OF HOUSING FOOD PROCESSING MANUFACTURING SMALL MANUFACTURING FOR THE BUILDING SECTOR HEALTH CENTRE COMMERCIAL PUBLIC/ADMINISTRATIVE

60%

SCHOOL housing commercial public institutions manufacturing

20%

attached, three storey, OSR 50 attached, double storey, OSR 45 attached, single storey, OSR 45 detached, double storey, OSR 40

detached, single storey, OSR 35 detached, single storey, OSR 15

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personal reflection

“Over the aim of understanding urban metabolism in small cities both in Thuringia and Ethiopia context, it had been expected to create tools for development and find a way for the tools to flow in between in compliance. The main struggle was finding the way to apply the tools that we found from analyzing Thuringia. The second one was understanding the challenges in Ethiopia’s prospects for enhancing its own economic and social growth performance, and the implications of the shift in the small towns through becoming urban centers, especially, the country that we could not have been before. We took into consideration of economic, social and environmental factors for more stable and sustainable development model. Within this approach we tried to find the limits of existing resources and enhance the existing potentials through the projected growth by government of Ethiopia.

It was challenging to create a development model for Ethiopia via taking references by Thuringia. Despite such two different contexts, it helps us to improve our skills to comprehend the limits of the development and how far a city could grow with convenient devices.” -CB „A glance into rural development, a metabolic approach to understanding the dynamics of small cities, the particularities of planning in a totally unfamiliar Sub-Saharan African environment, the advantages of computational urban analysis - this is the outline of what I learned a lot about during this project. Even planning in our own everyday environment is a great challenge, so unsurprisingly without a clear initial justification of why should we be able to find the answers to the problems of Ethiopian rural developments

the whole idea felt a little overwhelming and purposeless. But parallelly with deepening my understanding of the mentioned topics it also became clear, that with sufficient self-critique and enthusiasm we may be able to contribute to an important issue - which approach enabled me to work relieved from the initial pressure. The short time available made the group work more intense and forced us to rely on each other more. This along with the various consultations we received from different professionals enabled us to create a highly interdisciplinary approach to the planning of rural development centres in Ethiopia, and I hope it will be of value in the developments to come.” -MH “Planning communities far away from our reality is provoking, difficult, and sometimes overwhelming. It will not matter how

much we research, sit back and listen and let others tell their story, our perspective will remain no matter how far out of our comfort zone we stand. I have been seeking a stronger personal standpoint on what our role in planning can be, and sought to find a balance between discussing new notions of planning with bringing in my own ideas to provoke new thoughts. The interactions with our fellow exchange students from Addis Ababa has been the most fruitful ones, where so many ideas have been exchanged. I believe that we always have to ask, as professionals, as researchers, as students; why are WE doing this? How are OUR ideas legitimate? And with these questions in mind take the opportunity as a way of radically challenge our way of thinking about planning issues, to say that if our perspective is far away from the Ethiopians, then mustn’t our plans also shift? I

think we have just touched upon putting this into action, and I am eager to continue progress in this matter.” -JN “How do we find solutions for a place we have never been to? How can we know what is the best for people we have never met? How can we understand a culture we have never experienced? In the beginning of the project I found it difficult to understand what answer we can give to these questions. After some time I realised it is not about finding absolute solutions or giving the right answer. It is about transferring knowledge, showing up possible opportunities from our experiences and rethinking them in the new context; not repeating the same mistakes urbanised countries have made, but learning from them and thinking further in the search for new solutions in the urbanisation of rural areas. Seeing

urban developments in a metabolism way helped us to understand the impact of all the components and how they can complement each other. Ethiopia is currently in the state where it can still take other paths than already urbanised countries and develop in a socially inclusionary and an environmental friendly way. This opportunity has to be taken. We tried to do our best for the short time period we had. We have not come so far that I can say this would ensure a sustainable future for Dannisa and for the global context. This is why, it would be nice to continue this excursion into the world of Ethiopia.” -TP

references and acknowledgements

Acknowledgements During our work we have been supported by numerous people at the university. We would like to thank Philippe Schmidt and Sven Schneider for the regular consultations regarding the whole of our developed concept. Andreas Aicher for helping us with water related planning issues. Asgedom Haile for giving us insight to the Ethiopian building/construction sector. Martin Dennemark, Ondrej Vesely and Iuliia Osintseva for consultations regarding computational urban analysis. References Adesina, A. (2017). Using Agriculture and Agribusiness to Bring About Industrialization in Africa. Inter Press Service. Retrieved 6 July 2017, from http://www.ipsnews. net/2017/05/using-agriculture-and-agribusiness-to-bring-about-industrialisation-inafrica/ Afkari A. (2010). Sustainable Low-Cost Housing in Ethiopia - A Study of CSSBTechnology. Bachelor Thesis in Construction Engineering Programme. School of Business and Engineering, Halmstad University. Analyzing Urban Benchmarks: Production-Industry, (2017). Unpublished. Arnalich, S. (2010). Gravity Flow Water Supply. Conception, design and sizing for cooperation projects. Arnalich water & habitat. Davis, M (2017). Planet of Slums. Verso Books, Brooklyn New York. Donath, D. (2012). Experimental prototypes for emerging housing constructions in Addis Ababa, Ethiopia. Sustainable Futures: Architecture and Urbanism in the Global South. Kampala, Uganda. Dorosh, P & Schmitt, E (2010) The Rural-Urban Transformation in Ethiopia. Ethiopia Strategy Support Program II (ESSP II) International Food Policy Research Institute, Addis Ababa. Fabrizi, L. Water Supply in Small Communities. Lenntech BV. Delft, Netherlands. (retrieved from: http://www.lenntech.com/small-community-water-supplies.htm)

Franco, A. S., (2014). Mozambique-Embracing the Resource Boom. Perspective: Political Analysis and Commentary, (1), pp. 28-24. Germany, Heinrich-Böll Stiftung. Gebreeyesus, M., (2016). Industrial policy and development in Ethiopia: Evolution and present experimentation. Learning to Compete, No. 6. United Nations University World Institute for Development Economics Research. Retrieved 6 July 2017, from https:// www.brookings.edu/wp-content/uploads/2016/07/L2C_WP6_Gebreeyesus-1.pdf Golooba-Mutebi, F., (2014). Africa Rising-The Rwanda Story. Perspective: Political Analysis and Commentary, (1), pp. 20-35. Germany, Heinrich-Böll Stiftung. Hebel, D. E., Wisniewska, M. H., & Heisel, F. (2014). Building from waste: recovered materials in architecture and construction. Basel: Birkhäuser. Hjort, B., & Sendabo, T. (2006). Introduction of Sustainable Low - Cost Urban Housing with regard to Techno-Economic Aspects and Prevailing Attitudes - A Case Study. CIB W107 Construction in Developing Countries International Symposium “Construction in Developing Economies: New Issues and Challenges”. Santiago, Chile. Office for the Revision of Addis Ababa Master Plan. (2002). Norms and Standards of the Addis Ababa Structure Plan Components. Addis Ababa. Strawtech. (2015). Strawtech made in Rwanda. Kigali, Rwanda Taffese, W. (2012). Low-Cost Eco-Friendly Building Material: A Case Study in Ethiopia. International Journal of Civil, Environmental, Structural, Construction and Architectural Engineering, 6(2), 183-187. UN-Habitat. Water and Sanitation. (retrieved from: https://unhabitat.org/urbanthemes/water-and-sanitation-2/) Walle, H., Zewde, S., & Heldal, T. (2000). Building stone of central and southern Ethiopia: deposits and resource potential. NGU Bulletin, 436, 175-182. water.org. The Water Crysis. (retrieved from: https://water.org/our-impact/water-crisis/? gclid=Cj0KCQjw4vzKBRCtARIsAM3l8ODnHc5c1g3zWGfu6WJ9902LIJhQbPjmncewfTuQOaC3 nzMCoaiHlRkaAh7eEALw_wcB Wienerberger (2016). Brick. Simply better. Vienna, Austria