PhD, Faculty of Engineering and the Built Environment, University of the Witwatersrand, 2010 / Informal settlements are a growing world-wide phenomenon. Up-to-date spatial information mapping settlements is essential for a variety of end-user applications from planning settlement upgrading to monitoring expansion and infill. One method of gathering this information is through the analysis of nadir-view aerial imagery and the automated or semi-automated extraction of individual shacks. The problem of shack detection and delineation in, particularly South African, informal settlements is a unique and difficult one. This is primarily due to the inhomogeneous appearance of shack roofs, which are constructed from a variety of disparate materials, and the density of shacks. Previous research has focused mostly on the use of height data in conjunction with optical images to perform automated or semi-automated shack extraction. In this thesis, a novel approach to automating shack extraction is presented and prototyped, in which the appearance of shack roofs is homogenised, facilitating their detection. The main features of this strategy are: construction of an anisotropic scale-space from a single source image and detection of hypotheses at multiple scales; simplification of hypotheses' boundaries through discrete curve evolution and regularisation of boundaries in accordance with an assumed shack model - a 4-6 sided, compact, rectilinear shape; selection of hypotheses competing across scales using fuzzy rules; grouping of hypotheses based on their support for one another, and localisation and re-regularisation of boundaries through the incorporation of image edges. The prototype's performance is evaluated in terms of standard metrics and is analysed for four different images, having three different sets of imaging conditions, and containing well over a hundred shacks. Detection rates in terms of building counts vary from 83% to 100% and, in terms of roof area coverage, from 55% to 84%. These results, each derived from a single source image, compare favourably with those of existing shack detection systems, especially automated ones which make use of richer source data. Integrating this scale-space approach with height data offers the promise of even better results.

This thesis discusses the involvement of informally housed communities in shaping local government policies aimed at poverty alleviation. Involving the poor in the design of anti-poverty policies at local level is regarded as an invaluable opportunity that should be used by municipal governments to make poverty alleviation efforts more demand-driven and therefore more relevant to the people they are meant to benefit. The argument is that because the poor know about poverty first-hand, they would be in a position to revive local government's capacity to respond effectively to their needs. But this does not come without a price. Because of the complexity of public management, participative democracy is liable to slow down the process of governance. It may also become advantageous to the interests of some people or groups of people at the expense of others if attention is not paid to the representation and consideration of all the voices in the community–to name two drawbacks. For this reason, it is essential to the realization of an effective bottom-up approach to anti-poverty policy-making that certain conditions are in existence and practical issues of involvement are worked through. Accordingly, it is the intention of this study to focus on two particular areas (conditions and practical issues that would facilitate the process of involving informally housed communities in the design of local government policies that affect their lives), which are investigated with particular reference to the South African context. Drawing upon a series of field surveys and a broad selection of relevant works of scholars from both the international and local scene, the picture that emerges is that there needs to be a proper level of government's commitment, capacity and legally binding responsibility coupled with a healthy degree of community's motivation, ability and organizational capacity in order to involve the poor in local governance efficiently. The study has also found that there needs to be proper forms of involvement (the most relevant of which are identified as an ombudsman, public meetings and residents' committees) that are to be employed with attention to such issues as stakeholders to be engaged, degree of participation, timing of involvement and topics for which public debate may be sought. / Development Studies / D.Litt. et Phil. (Development Studies)

This thesis discusses the involvement of informally housed communities in shaping local government policies aimed at poverty alleviation. Involving the poor in the design of anti-poverty policies at local level is regarded as an invaluable opportunity that should be used by municipal governments to make poverty alleviation efforts more demand-driven and therefore more relevant to the people they are meant to benefit. The argument is that because the poor know about poverty first-hand, they would be in a position to revive local government's capacity to respond effectively to their needs. But this does not come without a price. Because of the complexity of public management, participative democracy is liable to slow down the process of governance. It may also become advantageous to the interests of some people or groups of people at the expense of others if attention is not paid to the representation and consideration of all the voices in the community–to name two drawbacks. For this reason, it is essential to the realization of an effective bottom-up approach to anti-poverty policy-making that certain conditions are in existence and practical issues of involvement are worked through. Accordingly, it is the intention of this study to focus on two particular areas (conditions and practical issues that would facilitate the process of involving informally housed communities in the design of local government policies that affect their lives), which are investigated with particular reference to the South African context. Drawing upon a series of field surveys and a broad selection of relevant works of scholars from both the international and local scene, the picture that emerges is that there needs to be a proper level of government's commitment, capacity and legally binding responsibility coupled with a healthy degree of community's motivation, ability and organizational capacity in order to involve the poor in local governance efficiently. The study has also found that there needs to be proper forms of involvement (the most relevant of which are identified as an ombudsman, public meetings and residents' committees) that are to be employed with attention to such issues as stakeholders to be engaged, degree of participation, timing of involvement and topics for which public debate may be sought. / Development Studies / D.Litt. et Phil. (Development Studies)