GISdevelopment.net --> Application --> Archaeology
Opportunities for enhancing communication settlement upgrading with GIT based support tools
Richard Sliuzas
ITC, The Netherlands
Email: sliuzas@itc.nl
Abstract
For many residents in developing cities, informal settlements are the sole avenue of access to shelter and basic services, however poor in quality. The need to improve the living conditions in such areas is once again receiving high priority on the international and national development agendas. Current approaches to settlement upgrading favour the adoption of community based, participatory styles of planning and management. Upgrading inevitably also requires the use, albeit in cooperation with local residents, of more traditional planning and design methods which depend in part on the ability to analyse the physical setting of a given settlement and prepare appropriate solutions to specific problems. Using several examples from informal settlements in Dar es Salaam, it will be shown how a hybrid approach to spatial data provision that incorporates both the traditional sources of spatial data and some of the more participatory approaches can be beneficial. The hybrid approach built around the use of a series of low-cost, up to date aerial mosaics provides relevant spatial data that is relevant and usable by both residents and professionals, thereby presenting opportunities for more communicative and transparent discussions between actors on possible interventions in the settlement.
Introduction
The inability of national and local governments in developing countries to cope with high rates of urbanization has given rise to the proliferation of informal settlements in many cities. These settlements provide shelter for as much as 86% of a city’s population under a variety of living conditions. The term informal here refers to the illegal status of land tenure and/or the non-adherence to building and infrastructure codes and given the scale of informality in many cities, may encompass considerable variation in socio-economic status and living conditions (Fekade 1997). The greatest challenges are presented by the so-called “disadvantaged settlements” (opcit1997) which tend to have the worst living conditions and have a high concentration of the urban poor, and most of the discussion focuses on this type of informal settlement.
The paper begins with an overview of major changes in formal responses to informality and urban management in developing countries. This is followed by an examination of current approaches to settlement upgrading that emphasize collaboration with community based organizations and a discussion of the requirements for spatial data in upgrading projects. Some findings from ongoing studies and research in several informal settlements in Dar es Salaam are used as a basis for the formulation of a hybrid approach to spatial data handling in the context of settlement upgrading projects.
Informality and urban management
Various responses to informal development have been developed since the late 1960’s when Turner and others successfully highlighted the fact that self-help housing was part of the solution to urban shelter provision. The demolition of slum and squatter areas and public housing programmes gradually gave way to in-situ settlement upgrading, often conducted in tandem with Sites and Service schemes (Fekade 1997). While these approaches did recognise the legitimate role of residents in constructing their own shelter, they also tended to adopt externally designed technocratic approaches with an emphasis on the design and construction of physical infrastructure i.e. roads and drainage, water supply and sanitation that did not relate well to the different development models 1 found in planned and unplanned development (Abbott 2001).
The inability of implementing agencies and governments to create sustainable and replicable settlement upgrading programmes contributed to reduced interest in continuing to finance such approaches in the 1980’s. The following period saw a concerted and coordinated shift by major international agencies such as the World Bank, UNCHS and UNDP in the Urban Management Programme (UMP). Central to this effort was the realization that urban areas are of fundamental importance in economic development and hence poverty alleviation. The UMP’s initial substantial emphasis on land management, infrastructure, finance and the environment included support for the selective deregulation of planning and development control processes and a shift toward an enabling role for the public sector and decentralization (Clarke 1991; Mattingly 1994; Wegelin 1994). The UMP approach has also been the subject of critical comment on its ideological linkages with neo-liberal thinking and practical considerations related to the devolution of responsibility without power and resources or pseudo-devolution (Werna 1995). According to Bu ek and Smith (2000, pg. 5) experience shows that to be successful decentralisation must be “..combined with democracy, accountability and responsibility at the local level leading to effective participation”, underlining the importance of governance in contemporary urban management within which settlement upgrading is an essential component.
The latest urban management approaches have responded by advocating more collaborative planning processes (Healey 1997) such as found in UNCHS’s Sustainable Cities Programme. Collaborative planning styles are promoted on the grounds that they are inclusive and provide opportunities for all voices to be heard. In practice the results may depend much on the attitudes of key actors, the level of foreclosure imposed by binding laws and regulations and the institutional complexity associated with vertical and horizontal collaboration between various actors and actor groups (Tewder-Jones 1998). An increasingly important role in collaborative planning is also seen for community groups and voluntary agencies, as key agents in urban development; groups that are believed to be critical to more open and inclusive governance systems, in particular for the most vulnerable and marginalized groups. Here it is important to realise that such bodies are not a priori models of good governance as they are also subject to problems such as internal power struggles, lack of accountability and lack of capacity that typify organisations in other sectors (Fowler 1997; Bûcek and Smith 2000).
Settlement upgrading
The upgrading of informal settlements is generally executed on a project by project basis, with each project phased over a number of years. The project model suggested by Davidson and Payne (2000) groups tasks into 5 main stages: Feasibility Studies, Detailed Studies, Developing Project Options, Detailed Development Proposals and Project Implementation. In each phase there are requirements for spatial information that present opportunities for the adoption of Geographic Information Technologies.
Conventional approaches to upgrading
In a conventional approach, such as was common in the 1970’s, a special unit would be established, usually within a government organisation or ministry, as the lead agency for a specific project. This unit would be responsible for overall project management and the coordination of the inputs of other agencies and organizations. Although most projects included elements of participation with community members, the level of participation was often relatively low and perhaps limited to their being informed about project progress or
1 The term development cycle refers to the development models proposed by Baross. The development sequence in sites and service schemes being Planning-Servicing-Occupation and Building (PSOB) as against Occupation-Building-Planning and Servicing (PBPS) that relates to informal development and in-situ upgrading. consulted on specific issues or proposals. In such projects the community is seen as the target of the project and not as a key partner in the development process. The danger is that lead agencies and professionals dominate the project, tend to adopt technocratic approaches to infrastructure and services yet fail to establish a local capacity for cost recovery, operations and maintenance (Werlin 1999).
Community based approaches
The essential difference between conventional and community based upgrading is in the adoption of a more inclusive, collaborative style of project planning and implementation. This provides for a high level of community mobilization and involvement in decision making that is an essential ingredient for successful upgrading (Werlin 1999, pg. 1529). While participatory appraisal methods have long been popular in rural development (Chambers 1994; Chambers 1994) they have also gained increasing ground in relation to urban planning issues such as upgrading (see for examples:WHO 1991; Wates 2000). In this approach a preliminary project stage of mobilisation may here be required for mutual awareness and sensitisation between the actors in the project. The realization that community participation may provide a means to address the long term sustainability of project benefits by encouraging a feeling of ownership and responsibility has further fostered the adoption of participatory approaches, though it will be some time before such impacts can be evaluated for, as Werlin (1999) points out, short term success is not an indicator of long term sustainability.
Basic issues in settlement upgrading
Broadly speaking, major issues in upgrading projects centre around 4 main topics: the nature of target population and in particular the most disadvantaged groups; the physical nature of the project site and prevailing land tenure arrangements; the nature and level of site development and the institutional and financial framework (Davidson and Payne 2000). In practice upgrading models and checklists should be used only as a guideline as there can be a great diversity in problems between settlements and local priorities should be used as the basis for decision making and planning. Engaging communities in setting the agenda for improvement will improve the relevance of the project but there are also some risks. Professional knowledge and experience is also required to ensure that related problems are dealt with in an integrated manner. For example, if roads are to be improved, there will be implications for storm water drainage that residents may not fully appreciate.
Spatial information requirements and the use of GIS
Recent work in Cape Town, South Africa has shown how spatial information and GIS can be applied in settlement upgrading (see for example: Abbott and Douglas 1998; Abbott 2001; Abbott 2001). This experience shows that a GIS based methodology can provide valuable support in upgrading projects. Three core data sets related to shacks, the occupants of the shacks and the spatial and physical aspects of the settlement are used to analyse issues and potential planning responses together forming an information backbone for the project. In the technical design processes experts can then draw on such databases and the designs themselves should also be compatible with the core data sets, in so far as scale and accuracy considerations allow 2 . The core spatial data sets may be derived from aerial
2 Although the spatial data in a GIS can be used to produce outputs at any scale they are not to all intents and purposes scale-less. The source of the data and data capture methods imply a certain level of accuracy and precision that will limit the usability of the data. For example, an engineer preparing designs for drainage systems in relatively flat areas may require precision of 1-2 cm in levels in order to ensure that water flows correctly. Such precise data can only be obtained via terrestrial surveys although less precise data from other sources may be usable in preliminary terrain studies and preparatory work Sliuzas, R. V. and M. Brussel (2000). Usability of large scale topographic data for urban planning and engineering applications: examples of housing studies and DEM generation in Tanzania. ISPRS, Amsterdam, ISPRS.. images in raster form but they will be predominantly object based, and therefore vector based.
One concern related to the use of GIT in participatory planning is that the technology itself has the potential to alienate and exclude non-GIT experts. Although the development and use of so-called Participatory GIS (PGIS) is an area attracting considerable interest amongst researchers, the use of such technology carries the risk of undermining participation rather than promoting it. When used with care and concern for these potential dangers successful GIS-based joint learning for planning collective action can be realised. Gonzalez (2000) for example used a PGIS approach in working with local communities in The Philippines, including data acquisition from aerial photographs and satellite images via a process she called “participatory image interpretation”.
Planners and engineers are trained to use spatial data that is stored and visualized in abstract vector formats at various scales. Their basic knowledge in the representation of reality cartographically, whether in the form of hardcopy maps or in a GIS provides them with a means to develop, design and communicate ideas for improving a settlement. But training is required to appreciate and use such abstract representations and many residents of informal settlements will not have this skill. The use of vector based representations of settlements therefore cannot be readily used as an instrument for mutual learning between residents and professionals and may in fact impede, rather than foster, community participation and knowledge sharing.
Aerial photographs, on the other hand, provide a less abstract image or reality, albeit from an unusual birds-eye view. Where recent photographs are available they can be used as a useful source of information in settlement upgrading by both professionals and residents. Much work at ITC includes the use of both vertical aerial photography and low-cost small format aerial photography (SFAP) in studies of informal development [some examples of this are \ (Bruijn 1987; Küpfer, Turkstra et al. 1987; Leelasena, Schaap et al. 1987; Sliuzas 1988) and the ease with which most residents are able to interpret aerial images of their own area is well recognised. The ability to create a temporally relevant view of a project area that is also geometrically compatible with other spatial data sources is an important feature of the SFAP approach. As such settlements are highly dynamic, SFAP techniques can be used to provide updated images of the settlement throughout the project cycle. Such a series of images can be used in a variety of ways beneficial to the upgrading process: to provide a record of physical development at throughout the project including both improvements and any additional informal developments; to provide documentary evidence of property demarcations (Nostrand 1986) and they can be an important instrument in mobilization by providing residents with an overview of the settlement for identifying problem areas and exploring possible solutions together with professionals.
The following section discusses informal settlements in Dar es Salaam and how the use of GIT could contribute to the community based upgrading approaches that are currently being followed. Two settlements Hanna Nassif and Tabata have been recently upgraded while the third, Keko Mwanga, is a densely developed but as yet unimproved.
Settlement upgrading, governance and GIT in Dar es Salaam
Changing attitudes to informal housing
Informal settlements have been a feature of Dar es Salaam for many years. Like other countries in the region, Tanzania inherited an urban planning system that was focussed more on the needs of the European population (Rakodi 1986; King 1991). In the colonial period the status of indigenous population was typically seen as only temporarily urban and this view was reflected in the relative disinterest in their living conditions. However, when the conditions in so-called African areas were seen to pose a potential threat to public health generally the colonial authorities may have intervened. Leslie (1963 ) for example reports that as early as 1947 the growth of slums and shanty areas in the city was out of control and in the same study identifies Keko, at this time, as being one of those areas “..dangerous to health and order”.
Policies on informal settlements in Dar have at different times emphasized different approaches. In the colonial period and shortly after independence they were often neglected or the subject of demolition and resettlement (Grohs 1973). In the 1970’s a combined sites and services/upgrading approach was adopted but with little long term impact (Magembe and Rodell 1983; Materu 1986; Schmetzer 1986; Kaitilla 1987; Kironde 1991; Materu 1993; Kyessi 1994). The reported problems generally matched those identified by Sanyal (1987) as contributing to the failure of such projects: a lack of understanding by residents on their obligations, inefficient collection of user charges, a lack of incentives and sanctions for compliance with requirements and insufficient political support. Ultimately, with the withdrawal of donor support for upgrading in the 1980’s, such projects were abandoned, though the sites and services unit within that was created for managing such projects remained in existence and did from time to time produce new “paper plans”. The failure of this approach left the provision of low-income housing largely to the informal sector and to some extent the housing needs of middle-income groups are also catered for via the same mechanism, as the state was also unable to provide adequate numbers of serviced plots for such groups.
Recent research by the author (Sliuzas 2001) on informal development that is the consequence of the ineffective formal land management and housing systems indicates that informal settlements are rapidly expanding while simultaneously, older more established settlements continue to consolidate via processes of densification. As part of this work a survey of local professionals has revealed that knowledge about the scale and extent of informal development processes tends to be scattered and piecemeal. Such “knowledge gaps” can act as barriers to the search for more effective land delivery and servicing systems and in the prioritization of action projects.
The adoption of community based upgrading
Since 1992 Dar’s urban planning system has been the subject of a major reform and revitalization effort. The traditional expert led planning approach (Armstrong 1986) based on received concepts, standards and procedures (Kironde 1992) has been moving toward more performance oriented planning through a combination of strategic planning and action planning (Halla 1994; Kyessi 1994; Davidson 1996). Community based action planning has been introduced in a number of informal settlements, including Hanna Nassif and Tabata (see Figure 1). Hanna Nassif which covers approximately 50 Ha and has a population of about 20,000, was the first settlement to be upgraded with a community based approach when the CBO approached the City Council for assistance to improve roads and reduce flooding problems. Over the period 1994-2000 various local and international organizations have worked with the community to improve living conditions, employing where possible local residents in construction activities. The Tabata project started in the mid 1990’s under the Community Infrastructure Project umbrella that was created to build on the Hanna Nassif experience. The area covered is 171 Ha with a population of about 14,000 that is in terms of income, more mixed that of Hanna Nassif (Kyessi 2000). These projects should be seen in the light of new governance structures that are emerging as part of a more radical overhaul of government system of which urban planning is one component.
Spatial data availability Currently investigations are being undertaken to identify the basic stages and activities related to spatial information in these projects 3 . Table 1 below provides an overview from 2 key professionals involved in the Hanna Nassif project. The initial spatial data deficiencies caused by the reliance on machine plots 4 were
Figure 1: location of case settlements
eventually overcome by the release of new maps in 1994. However, the project has run over a 6 year period and in that time no new photogrammetric mapping was carried out. The spatial data situation in Tabata was, if anything worse than in Hanna Nassif, as the upgrading of commenced there in 1996, 4 years after the best maps available were made.
Table 1: Overview of project stages and spatial data requirements and deficiencies in Hanna Nassif
community members and professionals that suggest there is considerable potential for exploiting such technology in upgrading projects as a means to improve the participation or residents and professionals in communication, planning and design processes.
Figure 2: Example of a PRA transect walk map produced in the Tabata upgrading project (source: Mwalukasa, 2001)
Production of SFAP mosaics for upgrading projects Previously SFAP and GIS have been used in several studies into informal development in Dar es Salaam but in this early work there were considerable problems associated with the inability to geometrically adjust the images sufficiently well enough for them to be considered comparable with topographic maps (Bruijn 1987; Sliuzas 1988; Kyessi 1990). In spite of this problem, in the hands of experienced users they could be a rich source of spatial information and allow insights into physical development processes to be studied in some detail.
Advances in desktop GIS have overcome this problem and several SFAP mosaics have now been made using SFAP images, including Keko Mwanga and Hanna Nassif (see Figure 3). The resulting mosaics are compatible with the digital topographic data available in Dar, have a pixel size of 20 cm and can be used to produce enlargements up to a scale of 1:1000, which is the scale required for detailed planning and design in Hanna Nassif (see example in Figure 4). In 1997, oblique images of Hanna Nassif were used by project consultants to prepare and implement a household survey. However, at that time a mosaic was not produced and the images were not available to community members. More recent work has attempted to provide some insight into this aspect.
Usability of maps and SFAP mosaics for community planning
Interviews conducted in 2000 with the Keko ward executive officer (WEO) and 2 mtaa 5 leaders from the Keko Mwanga settlement revealed that maps of these areas were not available for their use, although the former had on occasion seen them. Both the WEO and
5 A Mtaa is the lowest administrative area in the city. Mtaa leaders are elected by the residents and have certain responsibilities to manage their areas, but are at this time unpaid. the mtaa leaders stated that the SFAP mosaic (scale 1:1500) of Keko Mwanga settlement was easier to understand than the traditional map (1:2500). Though it was suggested that some annotations such as street names and names of public buildings such as the school, that are typically found on the maps would enhance the readability of the mosaic.
Figure 3: Mosaic of Hanna Nassif settlement produced from a 11 SFAP images made by the author in December 1999 with ILWIS software.
Figure 4: Section of Hanna Nassif mosaic at scale 1:1000 overlaid with building polygon outlines from topographic data at scale 1:2500, road centrelines and surface water drains.
The relative ease of use of the mosaic by untrained people was confirmed in a focus group session held later with a group of women and a group of men from the same community. Each person had no difficulty in identifying their own houses, some specific locations such as the school market and cemeteries and perhaps more importantly they were able to identify locations of specific problem areas related to problems such as flooding, waste dumping sites and poor accessibility.
Each mtaa leader received a copy of the mosaic of Keko Mwanga which was kept in their offices in a cardboard tube for protection against damage. The use made of the mosaics was monitored over a period of 3 months and again after 12 months 6 . Although neither leader had received any training in its use of interpretation, the mosaic was frequently used in a variety of ways (see Table 2). Further discussions with the leaders in June 2001 revealed that they continue to make frequent use of the mosaics and that they consider it to be a valuable resource in their work.
This experience is somewhat in contrast to that in Hanna Nassif. A similar mosaic, mounted in a frame protected by glass was presented to the Hanna Nassif Community Development Assocaition (HNCDA) in June 2001. From a recent meeting 7 attended by 15 HNCDA members (9 men and 6 women) it was found that most people considered it be for decorative purposes only and they cited the lack of training in how to use it in any other manner. However, when asked to consider further how it could be used in their activities they mentioned several the identification of newly constructed drains and water kiosks, locating households participating in the community’s credit scheme, facilitation of further planning for road and drain construction and as a general guide for the many visitors that come to the
6 Immediate follow-up work was carried out by Anthony Kibadu a local research assistant and in 2001 the area was visited by the author with a group of international professionals attending an international education programme at the ITC.
7 The meeting on 22 March 2002 was convened by Mr. S. Sheuya, a staff member of UCLAS who was involved in senior positions in the Hanna Nassif upgrading project between 1994 and 2000. area because of its leading role in community based upgrading in Dar. The community members also indicated a preference for 2 map scales: the 1:5000 image which provides an A4 sized overview of the entire settlement and the 1:1500 scale for more detailed work, though given the needs of planers and engineers, a scale of 1:1000 may be preferable.
Table 2: Uses made of SFAP mosaic of Keko Mwanga in the period April-June 2000.
It was also noted that development pressure has increased in Hanna Nassif since the upgrading project. Rising land prices and the sale of properties to seemingly more wealthy people has been observed, though no figures are available to confirm the extent to which this is occurring. Those present at the meeting saw that the investments of these wealthier newcomers as providing an economic stimulus to the area, but were at the same time concerned about their lack of affinity with the area and referred to their lack of knowledge and respect for plot boundaries. Whether such conflicts can be reduced with the help of the mosaic remains to be seen but it could provide a medium to introduce new residents to the settlement’s history and structure, raising their awareness of local issues and sensitivities with a view to minimizing the disruptive effects of local land conflicts.
Some considerations of governance and conclusions
The adoption of community based approaches to upgrading in Dar es Salaam is part of a more general reform of urban planning and management that is more participatory and seeks to improve the quality of the relationship between the state and civil society in which communication between the public sector and civil society is an essential element (Corubolo 1999). Participatory approaches can be used to mobilise community resources and allow formal organisations to gain access to the assets and information that exists in informal channels (opcit). However, if the capacity of local communities to engage in the improvement and management of their living environment is to be increased structural barriers to mutual learning and communication must be also addressed. This implies not only making information public (Rakodi 2001, pg 221) but ensuring that the medium of communication is understandable by the intended recipients.
The selection of spatial data for use in upgrading projects should explicitly consider the characteristics of all potential users of the data, to ensure that the cartographic communication process (Kraak and Brown 2000) will be truly effective. This view of is also supported by Geertman (Geertman 1999) who identifies the characteristics of the users as one of 4 factors that should be considered explicitly if GIT is to be used effectively. The examples from Dar es Salaam show that traditional topographic maps are not readily understood by residents in informal settlements while participatory maps such as those produced in Tabata are created by the community members but have limitations in terms of accuracy when they have to be integrated with topographic data. The ability to generate high quality SFAP mosaics in a PC based GIT opens new possibilities for spatial data provision, participation, communication and mutual learning. Such mosaics, enhanced with a minimal amount of topographic annotations, can be conceived of as a hybrid approach. As it has been shown to be easily understood and interpreted with relatively little instruction it would provide a basis for discussions at community meetings and could be directly annoted by community members during transect walks and participatory mapping exercises. These annotations could then be easily converted into digital form for later use by professionals and when required could be re-produced for community use. Given the accuracy achievable with image it can also be used to update the topographic data directly, providing further opportunities for property identification and registration and geo-referencing household information if and when required.
Further work is required to assess in practice how this and other GIT based tools can be applied to greatest effect in settlement upgrading. Two guiding principles are recommended for this work. Firstly, the characteristics and requirements of the community members who will be the key agents in determining the future development of the informal settlements in this work must be explicitly considered. Secondly, key products must be available at the community itself so that they can benefit directly from the availability of relevant spatial information in the daily management of their settlement.
References
Opportunities for enhancing communication settlement upgrading with GIT based support tools
Richard Sliuzas
ITC, The Netherlands
Email: sliuzas@itc.nl
Abstract
For many residents in developing cities, informal settlements are the sole avenue of access to shelter and basic services, however poor in quality. The need to improve the living conditions in such areas is once again receiving high priority on the international and national development agendas. Current approaches to settlement upgrading favour the adoption of community based, participatory styles of planning and management. Upgrading inevitably also requires the use, albeit in cooperation with local residents, of more traditional planning and design methods which depend in part on the ability to analyse the physical setting of a given settlement and prepare appropriate solutions to specific problems. Using several examples from informal settlements in Dar es Salaam, it will be shown how a hybrid approach to spatial data provision that incorporates both the traditional sources of spatial data and some of the more participatory approaches can be beneficial. The hybrid approach built around the use of a series of low-cost, up to date aerial mosaics provides relevant spatial data that is relevant and usable by both residents and professionals, thereby presenting opportunities for more communicative and transparent discussions between actors on possible interventions in the settlement.
Introduction
The inability of national and local governments in developing countries to cope with high rates of urbanization has given rise to the proliferation of informal settlements in many cities. These settlements provide shelter for as much as 86% of a city’s population under a variety of living conditions. The term informal here refers to the illegal status of land tenure and/or the non-adherence to building and infrastructure codes and given the scale of informality in many cities, may encompass considerable variation in socio-economic status and living conditions (Fekade 1997). The greatest challenges are presented by the so-called “disadvantaged settlements” (opcit1997) which tend to have the worst living conditions and have a high concentration of the urban poor, and most of the discussion focuses on this type of informal settlement.
The paper begins with an overview of major changes in formal responses to informality and urban management in developing countries. This is followed by an examination of current approaches to settlement upgrading that emphasize collaboration with community based organizations and a discussion of the requirements for spatial data in upgrading projects. Some findings from ongoing studies and research in several informal settlements in Dar es Salaam are used as a basis for the formulation of a hybrid approach to spatial data handling in the context of settlement upgrading projects.
Informality and urban management
Various responses to informal development have been developed since the late 1960’s when Turner and others successfully highlighted the fact that self-help housing was part of the solution to urban shelter provision. The demolition of slum and squatter areas and public housing programmes gradually gave way to in-situ settlement upgrading, often conducted in tandem with Sites and Service schemes (Fekade 1997). While these approaches did recognise the legitimate role of residents in constructing their own shelter, they also tended to adopt externally designed technocratic approaches with an emphasis on the design and construction of physical infrastructure i.e. roads and drainage, water supply and sanitation that did not relate well to the different development models 1 found in planned and unplanned development (Abbott 2001).
The inability of implementing agencies and governments to create sustainable and replicable settlement upgrading programmes contributed to reduced interest in continuing to finance such approaches in the 1980’s. The following period saw a concerted and coordinated shift by major international agencies such as the World Bank, UNCHS and UNDP in the Urban Management Programme (UMP). Central to this effort was the realization that urban areas are of fundamental importance in economic development and hence poverty alleviation. The UMP’s initial substantial emphasis on land management, infrastructure, finance and the environment included support for the selective deregulation of planning and development control processes and a shift toward an enabling role for the public sector and decentralization (Clarke 1991; Mattingly 1994; Wegelin 1994). The UMP approach has also been the subject of critical comment on its ideological linkages with neo-liberal thinking and practical considerations related to the devolution of responsibility without power and resources or pseudo-devolution (Werna 1995). According to Bu ek and Smith (2000, pg. 5) experience shows that to be successful decentralisation must be “..combined with democracy, accountability and responsibility at the local level leading to effective participation”, underlining the importance of governance in contemporary urban management within which settlement upgrading is an essential component.
The latest urban management approaches have responded by advocating more collaborative planning processes (Healey 1997) such as found in UNCHS’s Sustainable Cities Programme. Collaborative planning styles are promoted on the grounds that they are inclusive and provide opportunities for all voices to be heard. In practice the results may depend much on the attitudes of key actors, the level of foreclosure imposed by binding laws and regulations and the institutional complexity associated with vertical and horizontal collaboration between various actors and actor groups (Tewder-Jones 1998). An increasingly important role in collaborative planning is also seen for community groups and voluntary agencies, as key agents in urban development; groups that are believed to be critical to more open and inclusive governance systems, in particular for the most vulnerable and marginalized groups. Here it is important to realise that such bodies are not a priori models of good governance as they are also subject to problems such as internal power struggles, lack of accountability and lack of capacity that typify organisations in other sectors (Fowler 1997; Bûcek and Smith 2000).
Settlement upgrading
The upgrading of informal settlements is generally executed on a project by project basis, with each project phased over a number of years. The project model suggested by Davidson and Payne (2000) groups tasks into 5 main stages: Feasibility Studies, Detailed Studies, Developing Project Options, Detailed Development Proposals and Project Implementation. In each phase there are requirements for spatial information that present opportunities for the adoption of Geographic Information Technologies.
Conventional approaches to upgrading
In a conventional approach, such as was common in the 1970’s, a special unit would be established, usually within a government organisation or ministry, as the lead agency for a specific project. This unit would be responsible for overall project management and the coordination of the inputs of other agencies and organizations. Although most projects included elements of participation with community members, the level of participation was often relatively low and perhaps limited to their being informed about project progress or
1 The term development cycle refers to the development models proposed by Baross. The development sequence in sites and service schemes being Planning-Servicing-Occupation and Building (PSOB) as against Occupation-Building-Planning and Servicing (PBPS) that relates to informal development and in-situ upgrading. consulted on specific issues or proposals. In such projects the community is seen as the target of the project and not as a key partner in the development process. The danger is that lead agencies and professionals dominate the project, tend to adopt technocratic approaches to infrastructure and services yet fail to establish a local capacity for cost recovery, operations and maintenance (Werlin 1999).
Community based approaches
The essential difference between conventional and community based upgrading is in the adoption of a more inclusive, collaborative style of project planning and implementation. This provides for a high level of community mobilization and involvement in decision making that is an essential ingredient for successful upgrading (Werlin 1999, pg. 1529). While participatory appraisal methods have long been popular in rural development (Chambers 1994; Chambers 1994) they have also gained increasing ground in relation to urban planning issues such as upgrading (see for examples:WHO 1991; Wates 2000). In this approach a preliminary project stage of mobilisation may here be required for mutual awareness and sensitisation between the actors in the project. The realization that community participation may provide a means to address the long term sustainability of project benefits by encouraging a feeling of ownership and responsibility has further fostered the adoption of participatory approaches, though it will be some time before such impacts can be evaluated for, as Werlin (1999) points out, short term success is not an indicator of long term sustainability.
Basic issues in settlement upgrading
Broadly speaking, major issues in upgrading projects centre around 4 main topics: the nature of target population and in particular the most disadvantaged groups; the physical nature of the project site and prevailing land tenure arrangements; the nature and level of site development and the institutional and financial framework (Davidson and Payne 2000). In practice upgrading models and checklists should be used only as a guideline as there can be a great diversity in problems between settlements and local priorities should be used as the basis for decision making and planning. Engaging communities in setting the agenda for improvement will improve the relevance of the project but there are also some risks. Professional knowledge and experience is also required to ensure that related problems are dealt with in an integrated manner. For example, if roads are to be improved, there will be implications for storm water drainage that residents may not fully appreciate.
Spatial information requirements and the use of GIS
Recent work in Cape Town, South Africa has shown how spatial information and GIS can be applied in settlement upgrading (see for example: Abbott and Douglas 1998; Abbott 2001; Abbott 2001). This experience shows that a GIS based methodology can provide valuable support in upgrading projects. Three core data sets related to shacks, the occupants of the shacks and the spatial and physical aspects of the settlement are used to analyse issues and potential planning responses together forming an information backbone for the project. In the technical design processes experts can then draw on such databases and the designs themselves should also be compatible with the core data sets, in so far as scale and accuracy considerations allow 2 . The core spatial data sets may be derived from aerial
2 Although the spatial data in a GIS can be used to produce outputs at any scale they are not to all intents and purposes scale-less. The source of the data and data capture methods imply a certain level of accuracy and precision that will limit the usability of the data. For example, an engineer preparing designs for drainage systems in relatively flat areas may require precision of 1-2 cm in levels in order to ensure that water flows correctly. Such precise data can only be obtained via terrestrial surveys although less precise data from other sources may be usable in preliminary terrain studies and preparatory work Sliuzas, R. V. and M. Brussel (2000). Usability of large scale topographic data for urban planning and engineering applications: examples of housing studies and DEM generation in Tanzania. ISPRS, Amsterdam, ISPRS.. images in raster form but they will be predominantly object based, and therefore vector based.
One concern related to the use of GIT in participatory planning is that the technology itself has the potential to alienate and exclude non-GIT experts. Although the development and use of so-called Participatory GIS (PGIS) is an area attracting considerable interest amongst researchers, the use of such technology carries the risk of undermining participation rather than promoting it. When used with care and concern for these potential dangers successful GIS-based joint learning for planning collective action can be realised. Gonzalez (2000) for example used a PGIS approach in working with local communities in The Philippines, including data acquisition from aerial photographs and satellite images via a process she called “participatory image interpretation”.
Planners and engineers are trained to use spatial data that is stored and visualized in abstract vector formats at various scales. Their basic knowledge in the representation of reality cartographically, whether in the form of hardcopy maps or in a GIS provides them with a means to develop, design and communicate ideas for improving a settlement. But training is required to appreciate and use such abstract representations and many residents of informal settlements will not have this skill. The use of vector based representations of settlements therefore cannot be readily used as an instrument for mutual learning between residents and professionals and may in fact impede, rather than foster, community participation and knowledge sharing.
Aerial photographs, on the other hand, provide a less abstract image or reality, albeit from an unusual birds-eye view. Where recent photographs are available they can be used as a useful source of information in settlement upgrading by both professionals and residents. Much work at ITC includes the use of both vertical aerial photography and low-cost small format aerial photography (SFAP) in studies of informal development [some examples of this are \ (Bruijn 1987; Küpfer, Turkstra et al. 1987; Leelasena, Schaap et al. 1987; Sliuzas 1988) and the ease with which most residents are able to interpret aerial images of their own area is well recognised. The ability to create a temporally relevant view of a project area that is also geometrically compatible with other spatial data sources is an important feature of the SFAP approach. As such settlements are highly dynamic, SFAP techniques can be used to provide updated images of the settlement throughout the project cycle. Such a series of images can be used in a variety of ways beneficial to the upgrading process: to provide a record of physical development at throughout the project including both improvements and any additional informal developments; to provide documentary evidence of property demarcations (Nostrand 1986) and they can be an important instrument in mobilization by providing residents with an overview of the settlement for identifying problem areas and exploring possible solutions together with professionals.
The following section discusses informal settlements in Dar es Salaam and how the use of GIT could contribute to the community based upgrading approaches that are currently being followed. Two settlements Hanna Nassif and Tabata have been recently upgraded while the third, Keko Mwanga, is a densely developed but as yet unimproved.
Settlement upgrading, governance and GIT in Dar es Salaam
Changing attitudes to informal housing
Informal settlements have been a feature of Dar es Salaam for many years. Like other countries in the region, Tanzania inherited an urban planning system that was focussed more on the needs of the European population (Rakodi 1986; King 1991). In the colonial period the status of indigenous population was typically seen as only temporarily urban and this view was reflected in the relative disinterest in their living conditions. However, when the conditions in so-called African areas were seen to pose a potential threat to public health generally the colonial authorities may have intervened. Leslie (1963 ) for example reports that as early as 1947 the growth of slums and shanty areas in the city was out of control and in the same study identifies Keko, at this time, as being one of those areas “..dangerous to health and order”.
Policies on informal settlements in Dar have at different times emphasized different approaches. In the colonial period and shortly after independence they were often neglected or the subject of demolition and resettlement (Grohs 1973). In the 1970’s a combined sites and services/upgrading approach was adopted but with little long term impact (Magembe and Rodell 1983; Materu 1986; Schmetzer 1986; Kaitilla 1987; Kironde 1991; Materu 1993; Kyessi 1994). The reported problems generally matched those identified by Sanyal (1987) as contributing to the failure of such projects: a lack of understanding by residents on their obligations, inefficient collection of user charges, a lack of incentives and sanctions for compliance with requirements and insufficient political support. Ultimately, with the withdrawal of donor support for upgrading in the 1980’s, such projects were abandoned, though the sites and services unit within that was created for managing such projects remained in existence and did from time to time produce new “paper plans”. The failure of this approach left the provision of low-income housing largely to the informal sector and to some extent the housing needs of middle-income groups are also catered for via the same mechanism, as the state was also unable to provide adequate numbers of serviced plots for such groups.
Recent research by the author (Sliuzas 2001) on informal development that is the consequence of the ineffective formal land management and housing systems indicates that informal settlements are rapidly expanding while simultaneously, older more established settlements continue to consolidate via processes of densification. As part of this work a survey of local professionals has revealed that knowledge about the scale and extent of informal development processes tends to be scattered and piecemeal. Such “knowledge gaps” can act as barriers to the search for more effective land delivery and servicing systems and in the prioritization of action projects.
The adoption of community based upgrading
Since 1992 Dar’s urban planning system has been the subject of a major reform and revitalization effort. The traditional expert led planning approach (Armstrong 1986) based on received concepts, standards and procedures (Kironde 1992) has been moving toward more performance oriented planning through a combination of strategic planning and action planning (Halla 1994; Kyessi 1994; Davidson 1996). Community based action planning has been introduced in a number of informal settlements, including Hanna Nassif and Tabata (see Figure 1). Hanna Nassif which covers approximately 50 Ha and has a population of about 20,000, was the first settlement to be upgraded with a community based approach when the CBO approached the City Council for assistance to improve roads and reduce flooding problems. Over the period 1994-2000 various local and international organizations have worked with the community to improve living conditions, employing where possible local residents in construction activities. The Tabata project started in the mid 1990’s under the Community Infrastructure Project umbrella that was created to build on the Hanna Nassif experience. The area covered is 171 Ha with a population of about 14,000 that is in terms of income, more mixed that of Hanna Nassif (Kyessi 2000). These projects should be seen in the light of new governance structures that are emerging as part of a more radical overhaul of government system of which urban planning is one component.
Spatial data availability Currently investigations are being undertaken to identify the basic stages and activities related to spatial information in these projects 3 . Table 1 below provides an overview from 2 key professionals involved in the Hanna Nassif project. The initial spatial data deficiencies caused by the reliance on machine plots 4 were
eventually overcome by the release of new maps in 1994. However, the project has run over a 6 year period and in that time no new photogrammetric mapping was carried out. The spatial data situation in Tabata was, if anything worse than in Hanna Nassif, as the upgrading of commenced there in 1996, 4 years after the best maps available were made.
Table 1: Overview of project stages and spatial data requirements and deficiencies in Hanna Nassif
| Project stage | Activities related to collection, use or management of spatial information | Deficiencies in spatial information, effects and solutions |
| Project identification (Pre-CBO) Mtaa leaders and Balozi approach DCC for assistance with flooding | Initial identification of flood prone areas and definition of project area. | Initially only very poor quality maps (so- called machine plots) were available. These did not include contour lines. was Initial overview made by transect walks with local leaders. |
| Mobilization (sensitisation and awareness) | Standard 1:2500 maps used and rough version made at 1:1000. Settlement divided into zones for sensitisation meetings. One zone 40-60 people | As above: machine plots used. Zones were not mapped and people were not able to read maps effectively. so could not map problem areas. |
| Design and planning (Technical) | Sections (zones) enlarged to 1:1000 Line and level surveys conducted along all roads, major footpaths and in known flooding areas. Area divided into surface water catchments | Lack of information on location of existing water pipes so this was ignored and had to be dealt with later. |
| Implementation |
|
Water pipes were often left exposed in mid-air during construction. No way to visualise progress and future work. |
| Operation and | It was not planned to use maps. No maps of the settlement are | No information is available on this. |
community members and professionals that suggest there is considerable potential for exploiting such technology in upgrading projects as a means to improve the participation or residents and professionals in communication, planning and design processes.
Figure 2: Example of a PRA transect walk map produced in the Tabata upgrading project (source: Mwalukasa, 2001)
Production of SFAP mosaics for upgrading projects Previously SFAP and GIS have been used in several studies into informal development in Dar es Salaam but in this early work there were considerable problems associated with the inability to geometrically adjust the images sufficiently well enough for them to be considered comparable with topographic maps (Bruijn 1987; Sliuzas 1988; Kyessi 1990). In spite of this problem, in the hands of experienced users they could be a rich source of spatial information and allow insights into physical development processes to be studied in some detail.
Advances in desktop GIS have overcome this problem and several SFAP mosaics have now been made using SFAP images, including Keko Mwanga and Hanna Nassif (see Figure 3). The resulting mosaics are compatible with the digital topographic data available in Dar, have a pixel size of 20 cm and can be used to produce enlargements up to a scale of 1:1000, which is the scale required for detailed planning and design in Hanna Nassif (see example in Figure 4). In 1997, oblique images of Hanna Nassif were used by project consultants to prepare and implement a household survey. However, at that time a mosaic was not produced and the images were not available to community members. More recent work has attempted to provide some insight into this aspect.
Usability of maps and SFAP mosaics for community planning
Interviews conducted in 2000 with the Keko ward executive officer (WEO) and 2 mtaa 5 leaders from the Keko Mwanga settlement revealed that maps of these areas were not available for their use, although the former had on occasion seen them. Both the WEO and
5 A Mtaa is the lowest administrative area in the city. Mtaa leaders are elected by the residents and have certain responsibilities to manage their areas, but are at this time unpaid. the mtaa leaders stated that the SFAP mosaic (scale 1:1500) of Keko Mwanga settlement was easier to understand than the traditional map (1:2500). Though it was suggested that some annotations such as street names and names of public buildings such as the school, that are typically found on the maps would enhance the readability of the mosaic.
Figure 3: Mosaic of Hanna Nassif settlement produced from a 11 SFAP images made by the author in December 1999 with ILWIS software.
Figure 4: Section of Hanna Nassif mosaic at scale 1:1000 overlaid with building polygon outlines from topographic data at scale 1:2500, road centrelines and surface water drains.
The relative ease of use of the mosaic by untrained people was confirmed in a focus group session held later with a group of women and a group of men from the same community. Each person had no difficulty in identifying their own houses, some specific locations such as the school market and cemeteries and perhaps more importantly they were able to identify locations of specific problem areas related to problems such as flooding, waste dumping sites and poor accessibility.
Each mtaa leader received a copy of the mosaic of Keko Mwanga which was kept in their offices in a cardboard tube for protection against damage. The use made of the mosaics was monitored over a period of 3 months and again after 12 months 6 . Although neither leader had received any training in its use of interpretation, the mosaic was frequently used in a variety of ways (see Table 2). Further discussions with the leaders in June 2001 revealed that they continue to make frequent use of the mosaics and that they consider it to be a valuable resource in their work.
This experience is somewhat in contrast to that in Hanna Nassif. A similar mosaic, mounted in a frame protected by glass was presented to the Hanna Nassif Community Development Assocaition (HNCDA) in June 2001. From a recent meeting 7 attended by 15 HNCDA members (9 men and 6 women) it was found that most people considered it be for decorative purposes only and they cited the lack of training in how to use it in any other manner. However, when asked to consider further how it could be used in their activities they mentioned several the identification of newly constructed drains and water kiosks, locating households participating in the community’s credit scheme, facilitation of further planning for road and drain construction and as a general guide for the many visitors that come to the
6 Immediate follow-up work was carried out by Anthony Kibadu a local research assistant and in 2001 the area was visited by the author with a group of international professionals attending an international education programme at the ITC.
7 The meeting on 22 March 2002 was convened by Mr. S. Sheuya, a staff member of UCLAS who was involved in senior positions in the Hanna Nassif upgrading project between 1994 and 2000. area because of its leading role in community based upgrading in Dar. The community members also indicated a preference for 2 map scales: the 1:5000 image which provides an A4 sized overview of the entire settlement and the 1:1500 scale for more detailed work, though given the needs of planers and engineers, a scale of 1:1000 may be preferable.
Table 2: Uses made of SFAP mosaic of Keko Mwanga in the period April-June 2000.
|
User group Mtaa leaders and community management committees Municipal planners and engineers Wateraid (NGO) Solid waste collectors (private/CBO) Bureau of Statistics |
Summary of use made As a general communication tool when visitors come to the area as it provides a good overview of the settlement and is useful to highlight specific features and problems In discussions about a possible school expansion to delineate the expansion area, identify buildings for purchase and estimate the cost of compensation. Delineation of flood prone areas and possible need for house relocation – originally the work was to be done using 1992 maps of the area but the mosaic was found to be more up to date and easier to use for orientation and identification of buildings. To identify sites for new bore holes for water supply. The mosaics were used in the field and were borrowed and used to present the results to the Wateraid management. To identify sites for solid waste collection. It was also seen to be useful for house identification in the revenue collection process. Mosiac used in preparation for new census for the delineation of enumeration units – boundaries were delineated on the mosaic and transferred to their own maps. |
It was also noted that development pressure has increased in Hanna Nassif since the upgrading project. Rising land prices and the sale of properties to seemingly more wealthy people has been observed, though no figures are available to confirm the extent to which this is occurring. Those present at the meeting saw that the investments of these wealthier newcomers as providing an economic stimulus to the area, but were at the same time concerned about their lack of affinity with the area and referred to their lack of knowledge and respect for plot boundaries. Whether such conflicts can be reduced with the help of the mosaic remains to be seen but it could provide a medium to introduce new residents to the settlement’s history and structure, raising their awareness of local issues and sensitivities with a view to minimizing the disruptive effects of local land conflicts.
Some considerations of governance and conclusions
The adoption of community based approaches to upgrading in Dar es Salaam is part of a more general reform of urban planning and management that is more participatory and seeks to improve the quality of the relationship between the state and civil society in which communication between the public sector and civil society is an essential element (Corubolo 1999). Participatory approaches can be used to mobilise community resources and allow formal organisations to gain access to the assets and information that exists in informal channels (opcit). However, if the capacity of local communities to engage in the improvement and management of their living environment is to be increased structural barriers to mutual learning and communication must be also addressed. This implies not only making information public (Rakodi 2001, pg 221) but ensuring that the medium of communication is understandable by the intended recipients.
The selection of spatial data for use in upgrading projects should explicitly consider the characteristics of all potential users of the data, to ensure that the cartographic communication process (Kraak and Brown 2000) will be truly effective. This view of is also supported by Geertman (Geertman 1999) who identifies the characteristics of the users as one of 4 factors that should be considered explicitly if GIT is to be used effectively. The examples from Dar es Salaam show that traditional topographic maps are not readily understood by residents in informal settlements while participatory maps such as those produced in Tabata are created by the community members but have limitations in terms of accuracy when they have to be integrated with topographic data. The ability to generate high quality SFAP mosaics in a PC based GIT opens new possibilities for spatial data provision, participation, communication and mutual learning. Such mosaics, enhanced with a minimal amount of topographic annotations, can be conceived of as a hybrid approach. As it has been shown to be easily understood and interpreted with relatively little instruction it would provide a basis for discussions at community meetings and could be directly annoted by community members during transect walks and participatory mapping exercises. These annotations could then be easily converted into digital form for later use by professionals and when required could be re-produced for community use. Given the accuracy achievable with image it can also be used to update the topographic data directly, providing further opportunities for property identification and registration and geo-referencing household information if and when required.
Further work is required to assess in practice how this and other GIT based tools can be applied to greatest effect in settlement upgrading. Two guiding principles are recommended for this work. Firstly, the characteristics and requirements of the community members who will be the key agents in determining the future development of the informal settlements in this work must be explicitly considered. Secondly, key products must be available at the community itself so that they can benefit directly from the availability of relevant spatial information in the daily management of their settlement.
References
- Abbott, J. (2001). “An analysis of informal settlement upgrading and critique of existing methodological approaches.” submitted to Habitat Intl. Feb. 2001.
- Abbott, J. (2001). “A method-based planning framework for informal settlement upgrading.” submitted to Habitat Intl. June 2001.
- Abbott, J. (2001). “The use of spatial data to support the integration of informal settlements into the formal city.” International Journal of Applied Earth Observation and Geoinformatics 3: 267-277.
- Abbott, J. and D. Douglas (1998). The development of a GIS system for the provision of housing for in-situ informal settlement upgrading. Int. Conference on Shelter in Africa, Cape Town, South Africa.
- Armstrong, A. (1986). “Tanzania's expert - led planning: an assessment.” African Environment 17-18-19: 117-127.
- Bruijn, C. A. d. (1987). “Monitoring a large squatter settlement in Dar es Salaam with sequential aerial photography.” ITC Journal(3): 233-238.
- Bûcek, J. and B. Smith (2000). “New approaches to local democracy: direct democracy, participation and the 'third sector'.” Environment and Planning C: Government and Policy 18: 3-16.
- Chambers, R. (1994). “Participatory Rural Appraisal (PRA): Analysis of experience.” World Development 22(9): 1253-1268.
- Chambers, R. (1994). “Participatory Rural Appraisal (PRA): Challenges, potentials and paradigm.” World Development 22(10): 1437-1454. Clarke, G. (1991). “Urban management in developing countries. A critical role.” Cities(May): 93-107.
- Corubolo, E. (1999). Some ideas on governance from N-AERUS: 4., Discussion paper prepared for the Network Association of European Researchers on Urbanisation in the South.
- Davidson, F. (1996). “Planning for performance: requirements for sustainable development.” Habitat International 20(3): 445-462.
- Davidson, F. and G. K. Payne (2000). Urban Projects Manual. Liverpool, Liverpool Uiversity Press for DFID.
- Fekade, W. (1997). Formal urban land management and informal responses. A cross country literature review. Transformation von Wirtschaftssystemen, Dortmund/Dar es Salaam.
- Fowler, A. (1997). Striking a balance. A guide to enhancing the effctiveness of Non-Governmental Organisations in International Development. London, Earthscan Publications Ltd.
- Geertman, S. (1999). Geographical Information Technology and Strategic Physical Planning.
- Geographical Information and Planning. J. Stillwell, S. Geertman and S. Openshaw. Berlin-Heidelberg, Springer-Verlag.
- Gonzalez, R. M. (2000). Platforms and terraces: bridging participation and GIS in joint-learning for watershed management with the Ifugaos of the Philippines. Enschede/Wageningen, ITC/Wageningen University: 186.
- Grohs, G. (1973). Slum clearance in Dar es Salaam. Urban Challenge. J. Hutton. Nairobi, East African Publishing House: 94-104.
- Halla, F. (1994). “A coordinating and participatory approach to managing cities. The case of the Sustainable Dar es Salaam Project in Tanzania.” Habitat International 18(3): 19-31.
- Healey, P. (1997). Collaborative Planning. Shaping places in fragmented cities. Basingstoke, UK, Macmillan Press Ltd.
- Kaitilla, S. (1987). “The land delivery mechanism in Tanzania. The implications for a socialist state.” Habitat International 11(3): 53-59.
- King, A. D. (1991). Urbanism, colonialism, and the world economy: cultural and spatial foundations of the world urban system. London, Routledge.
- Kironde, J. M. L. (1991). “Sites and services in Tanzania. The case of Sinza, Kijitonyama and Mikocheni areas in Dar es Salaam.” Habitat International 15(1/2): 27-38.
- Kironde, J. M. L. (1992). “Received concepts and theories in African urbanisation and management strategies: The struggle continues.” Urban Studies 29(8): 1277-1292.
- Kraak, M. J. and A. Brown, Eds. (2000). Web cartography, developments and prospects. London, Taylor & Francis.
- Küpfer, G., J. Turkstra, et al. (1987). “Spatial growth of unplanned areas in Nairobi: use of aerial photographs for monitoring urban growth and improvement planning.” ITC Journal(3): 239-247.
- Kyessi, A. G. (1990). Urbanisation of fringe villages and growth of squatters: the case of Dar es Salaam, Tanzania. Urban Survey and Human Settlement Analysis. Enschede, ITC.
- Kyessi, A. G. (1994). “Squatter settlement development and upgrading in Dar es Salaam, Tanzania.” The Journal of Building and Land Development 3(2): 23-30.
- Kyessi, A. G. (1994). Urban planning of human settlements: Intersectoral co-ordination in planning and implementation - Strategies and Mechanisms: the case of Dar es Salaam. International Conference on Re-appraising the Urban Planning Process as an instrument for sustainable urban development and management, Dar es Salaam.
- Kyessi, A. G. (2000). Community participation in urban infrastructure provision: servicing informal settlements in Dar es Salaam. Faculty of Spatial Planning. Dortmund, University of Dortmund.
- Leelasena, W. M., A. D. J. Schaap, et al. (1987). “Public participation in integrated rural development projects: a case study of Hambantota District, Sri Lanka.” ITC Journal 3: 222-232.
- Leslie, J. A. K. (1963). A survey of Dar es Salaam, Oxford University Press.
- Magembe, E. J. A. and M. J. Rodell (1983). Housing production in selected areas of Dar es Salaam, Tanzania: a comparative study of sites and services, squatter and upgrading areas. Dar es Salaam, Centre for Housing Studies
- Institute for Housing Studies.
- Materu, J. (1986). “Sites and services projects in Tanzania: a case study of implementation.” Third World Planning Review 8(2): 121-138.
- Materu, J. (1993). An overview of the performance of the shelter sector in Tanzania. Fifth HABINET International seminar on Construction Management for Sustainable Self-Help Housing in Habinet Countries, Dar es Salaam, Centre for Housing Studies.
- Mattingly, M. (1994). “The meaning of urban management.” Cities 11(3): 201-205.
- Mwalukasa, M. B. M. (2001). SFAP as data source for strategic urban planning and management applications: A case study of Community Based Infrastructure Upgrading Programme in Dar es Salaam, Tanzania. UPLA. Enschede, ITC.
- Nostrand, J. v. (1986). Squatter and urban upgrading and the idea of a town: lessons in urbanization from Botswana and Lesotho. International symposium Strategies for slum and squatter upgrading in the developing world, Berlin.
- Rakodi, C. (1986). “Colonial urban policy and planning in Northern Rhodesia and its legacy.” Third World Planning Review 8(3): 193-217.
- Rakodi, C. (2001). “Forget planning, put politics first? Priorities for urban management in developing countries.” International Journal of Applied Earth Observation and Geoinformatics(3): 209-223.
- Sanyal, B. (1987). “Problems of cost-recovery in development projects: experience of the Lusaka squatter upgrading and site/service project.” Urban Studies 24: 285-295.
- Schmetzer, H. (1986). Slum upgrading and Sites-and-Services schemes under different political circumstances: experiences from East Africa. Strategies for slum and squatter upgrading in the developing world., Berlin, TRIALOG.
- Sliuzas, R. V. (1988). Problems in monitoring the growth of a squatter settlement: the housing process in Manzese, Dar es Salaam. Department of Urban Survey and Human Settlement Analysis. Enschede, ITC.
- Sliuzas, R. V. (2001). “Understanding the dynamics of informal housing in Dar es Salaam: an exploration of professional knowledge and opinions.” TRIALOG 69(2): 41-46.
- Sliuzas, R. V. and M. Brussel (2000). Usability of large scale topographic data for urban planning and engineering applications: examples of housing studies and DEM generation in Tanzania. ISPRS, Amsterdam, ISPRS.
- Tewder-Jones, M., Thomas, H. (1998). “Collaborative action in local plan-making: planners' perceptions of 'planning through debate'.” Environment and Planning B: Planning and Design 25: 127-144.
- Wates, N., Ed. (2000). The community planning handbook: how people can shape their cities, towns and villages in any part of the world. London, Earthscan Publications Ltd.
- Wegelin, E. (1994). The Urban Management Programme and Integrated Urban Infrastructure Development. unknown.
- Werlin, H. (1999). “The slum upgrading myth.” Urban Studies 36(9): 1523-1534.
- Werna, E. (1995). “The management of urban development, or the development of urban management? Problems and premises of an elusive concept.” Cities 12(5): 353-359.
- WHO (1991). Surface water drainage for low-income communities. Geneva, World Health Organization.