3. Electronic Theses and Dissertations (ETDs) - All submissions
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Item Using an anisotropic diffusion scale-space for the detection and delineation of shacks in informal settlement imagery(2011-05-04) Levitt, Stephen PhillipInformal 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.Item The persistent urban challenges of migration and informal settlements in the context of HIV: towards the development of a framework to guide the appropriate and equity promoting urban health and developmental responses of local government within Johannesburg, South Africa(2011-01-25) Vearey, Joanna LouiseRationale Understanding how to ensure and sustain the health and health equity of urban populations is of increasing importance as over half of the world population is now urban (UNFPA, 2007). Urbanisation is taking place rapidly across Africa, with fifty percent of the continent expected to be residing in urban areas by 2030 (UNFPA, 2007). South Africa has experienced a faster rate of urbanisation compared to neighbouring countries, with almost sixty percent of the population estimated to be urban (Kok & Collinson, 2006). This process of urban growth is accompanied by in-migration from within the country and across borders. Urban growth places pressure on limited, well-located and appropriate housing, resulting in the development of informal settlements within and on the periphery of urban areas. In addition to the multiple exposures to a variety of health hazards in informal settlements, HIV presents a contextual challenge, particularly in South Africa where the highest HIV prevalence is found within urban informal settlements (Shisana, Rehle, Simbayi, Parker, Zuma, Bhana et al., 2005). South African local government has a ‘developmental mandate’ which calls for government to work with citizens to develop sustainable interventions to address their social, economic and material needs (The Republic of South Africa, 1998a). This requires local government to address the challenges of urban growth, migration, informal settlements and HIV, as outlined above (Bocquier, 2008; Landau & Singh, 2008; Landau, 2007). The current (2007 – 2011) South African National Strategic Plan (NSP) for HIV signalled a welcome shift in HIV policy, with recognition of the role of government in ensuring that (1) internal and cross-border migrant groups and (2) residents of informal settlements are able to access the continuum of HIV-related services, which includes prevention, testing, support, treatment, and access to basic services. However, guidelines are lacking to assist local government in addressing HIV-related concerns with migrant groups and in informal settlements at the local level. As a result, migrant groups and residents of informal settlements struggle to access HIV-related services, including healthcare, adequate housing, and basic services such as water, sanitation and refuse removal. Given the developmental mandate of local government in South Africa (The Republic of South Africa, 1998a), this raises the question: how should local government respond to the urban challenges of migration and informal settlements in the context of high HIV prevalence? This thesis explores how the challenges of migration and informal settlements – within a context of high HIV prevalence – interact to generate a specific urban reality that requires an appropriate urban health response at the local government level. The question of how to address the gap between discourse, theory and action is tackled. Various frameworks for urban health have been developed that aim to assist in understanding the impact of city living on urban health, several of which draw on the concept of the social determinants of urban health (SDUH) (for example Galea, Freudenberg, & Vlahov, 2005; WHO, 2008b, 2008a). However, as I will go on to argue, none of the existing urban health frameworks deal adequately with the specific complexities of developing country urban environments. In particular, the frameworks have failed to adequately account for guiding local government in responding to the challenges identified above, namely: urban growth and informal settlements; internal and cross-border migration; high HIV prevalence; and, the responsibilities of a developmental local government. Aim Based on the findings from four studies, this PhD research aims to generate a revised urban health framework that will address the following specific challenges that I argue are associated with developing country contexts: (1) urban growth and informal settlements; (2) internal and cross-border migration; (3) high HIV prevalence; and, (4) the responsibilities of developmental local government. It is proposed that this revised framework will assist local government in responding to the interlinked challenges of informal settlements and migration in a context of high HIV prevalence. Methods A series of four studies were undertaken in Johannesburg. A review of international and local literature – including existing policy – was undertaken. In order to engage with the complexity of the urban environment, the four studies draw on both quantitative and qualitative methods. These include: a cross-sectional household survey across Johannesburg inner-city and one urban informal settlement (n = 487); a cross-sectional survey with ART clients at four ART sites in the inner-city (n = 449); and semi-structured interviews with community health worker volunteers, healthcare providers, local level policy makers and programmers involved with urban health and HIV in Johannesburg. By reflecting on involvement in participatory photography and film projects, the experiences of rural migrants who enter the city through ‘hidden spaces’ are examined; the concept of ‘being hidden’ is explored as a tactic employed by marginalised groups so that they are able to find a way to enter and participate in the city. Through the four studies, a series of four central themes were identified: (1) rights to the urban social determinants of health; (2) urban livelihoods; (3) policy and governance; and (4) urban methodologies. These four themes assist in synthesising the study findings and generating a revised approach to guide local government in responding to urban health challenges in a developmental way. Key findings The developmental mandate of local government is evolving very slowly (Paper I, V). Local level responses to the interlinked urban health challenges of migration, informal settlements and HIV are lacking (Paper I, V). Where they do exist, HIV is not viewed as an intersectoral developmental challenge and vertical HIV programmes prevail (Paper V). It will be argued that informal settlements require integrated local developmental responses (Paper V). In general, policies and guidelines that outline the right to basic healthcare and ART for crossborder migrants are not implemented at the local level (Papers I and III). In addition, residents of informal settlements struggle to access adequate housing and basic services (Papers IV and V). Some internal migrant groups, who reside in ‘hidden spaces’ of the innercity, are found to employ deliberate tactics in order to evade the state, whilst others are marginalised through a lack of state intervention (Paper II). The research shows that innovative methods are required to engage with urban populations, both for research and intervention purposes. Participatory approaches are found to be useful methods for engaging with urban migrant groups and this research draws on participatory photography and film projects as examples (Paper II, V). It is essential that urban public health practitioners and other development professionals learn how to engage with the complexities of the urban environment. A review of existing urban health frameworks finds that whilst these frameworks are themselves complex, and include the multiple levels and determinants that ultimately impact health outcomes, they result in generalised and static models of urban health. I argue that these existing frameworks are unable to inform responses to the specific complexities present within a particular urban context. Through the synthesis of the four study findings, an alternative approach to assist local government and other stakeholders in responding to urban health challenges is proposed. The idea of ‘concept mapping’ is suggested as a way to vii enable local government, and other actors, to engage with the complexities of the urban context in a participatory way. A core set of components have been identified that can be used to guide the creation of city-specific ‘concept maps’, that are able to work towards identifying and addressing the specific urban health needs associated with different areas within a city. A recommitment to intersectoral action, ‘healthy urban governance’ and public health advocacy is considered critical to the effectiveness of such an approach. It is suggested that the resultant ‘concept map’ will assist local government in responding in a developmental way to the interlinked challenges of migration and informal settlements in a context of high HIV prevalence. Implications Based on the findings of the PhD research, a new approach to urban health is suggested. ‘Concept mapping’ is presented as a new tool to assist local government in achieving its developmental mandate and address urban health. Whilst developed to address the challenges faced by urban migrants and residents of informal settlements in a context of high HIV prevalence, the concept map approach is likely to be a useful tool for considering the health and development needs of other urban groups. Future research is needed to evaluate the effectiveness of the application of participatory ‘concept mapping’ to assisting local level urban health policy makers, planners, and other stakeholders respond to the interlinked challenges of migration and informal settlements in a context of HIV.Item An assessment of the Johannesburg's Human Development Strategy and its appropriateness in dealing with HIV/AIDS in informal settlements(2008-10-06T07:59:59Z) Thabane, TsholofeloWhen HIV/AIDS first emerged from the shadows decades ago, few people could visualise how the epidemic would evolve, and fewer still could describe with any certainty the best ways of combating it. Today, we know from experience that the impact of HIV/AIDS thrives in conditions of socio-economic vulnerability and inequity. We are witnessing how HIV/AIDS is devastating regions, widening the gap between the rich and the poor, pushing the already stigmatised groups further away and destroying the sustainability of communities and their development conditions. The burden lies on local governments, National as well as regional authorities to take a more proactive role in confronting the pandemic and to prioritise activities geared towards the prevention of the spread of the disease. To fight poverty is to promote human development thus broadening people’s choices. This research project assesses the current practices that Johannesburg government has taken as an appropriate strategy to fight HIV/AIDS in Informal Settlements using the Human Development Strategy. Assessing the appropriateness of Human Development Strategy, an Informal Settlement named Sol Plaatjies, which is situated in Region 5 of Johannesburg, is used as a case study. The appropriateness of this strategy is measured against its ability to reduce the effects that are brought about by the HIV/AIDS since this strategy has been implemented in Sol Plaatjies.Item Socio-spatial exclusions and the urbanisation of injustice: a case study in northern Johannesburg(2008-03-07T10:15:37Z) Brett, JamesThe dissertation employs insights from critical race theory and the environmental justice literature, questioning the sustainability of dominant state policies concerning development of informal settlements. The work explores spatialized and racialised forms of class and their normalisation in South Africa. Discussion of the rise and redefinition of urban segregation in South Africa notes racialised exclusions have not disappeared with the end of apartheid. Economic supremacy of ‘white’ populations reproduces ‘white’ control – with dirt, crime and disorder constitutive of the pathological spaces of the ‘other’. Second part examines the role of environmental ideas in reproducing ‘white’ spaces of privilege and ‘black’ spaces of degradation. Discussing neo-liberal development, sustainable development and ecological justice in South Africa – the dissertation shows service delivery and housing policy to possess similarities to apartheid projects – with weaknesses of the dominant model failing the requirements of environmental justice. The case study which follows examines a contemporary attempt to relocate an informal settlement sited in an affluent neighbourhood through ‘greenfields’ housing development, revealing environments as contested, with spatial subjugation dramatic and ongoing.Item Community Participation in the Upgrading of Informal Settlements with reference to Thembelihle and Kanana informal settlements, Johannesburg(2006-11-14T11:13:34Z) Nemaonzeni, Ephraim RaphalalaniThis study engages with community participation in post-apartheid South Africa, in an attempt to discern participation approaches that might enhance development in the upgrading of informal settlements within the Metropolitan Cities. The research attempts to come up with an intervention strategy that incorporates participation of Community- Based Organisations, Community leaders and society into informal settlement interventions in South Africa. It reviews the South African framework and structures for informal settlement community participation (including civic organisations, other community-based organisatios, and elected statutory representation). It then examines to what extent lessons from the International literature review 2003 study conducted by Thabelo Nethenzheni may be relevant to the South African situation.Item Fertility Levels and Differentials in Informal Settlements in South Africa: Evidence from the 2001 South African Population Census.(2006-11-13T13:28:09Z) Mpezo, MuanzuPrevious studies on fertility in South Africa have mostly focused on the analysis of fertility trends, levels and differentials at the national level and have argued that socioeconomic development affects the national fertility level. This study examines the fertility levels in South Africa informal settlements with a view of examining whether there is any fertility variation between national and informal settlements. Data from the South Africa 2001 Census 10 per cent sample were used. Three levels of analysis were conducted. One examines fertility differentials. Two, multiple regression technique was applied to identify important socioeconomic factors of fertility in South African informal settlements and finally direct and indirect estimation of fertility was done. There is no difference in fertility levels between national and informal settlements. Fertility of 3 children per woman, in informal settlements is close to the national figure of 2.9. It is also shown that there is an inverse relationship between fertility and education and income, in South Africa informal settlements. Multivariate analysis shows that only about 6% of the variation in the dependent variable can be explained by the socioeconomic factors considered in the study. Fertility in the informal settlements was highest amongst women with higher education, among married women, and among those unemployed. In addition, the fertility of Christian women, and those women dwelling in households without radio and television was high. It is found that there is no difference between fertility levels at the national and informal settlements levels.Item The integration of housing rights into the informal settlement intervention process: An international review(2006-10-31T08:21:17Z) Ismail, Mohamed Iqbal EbrahimThe failure of governments to promote efficient housing policies coupled with increasing speculation in land markets has resulted in scarcity of serviced land, leading to a lack of adequate housing for the majority of the urban population. This has resulted in illegal land use and development and the eventual situation of informal settlements developing at a rapid rate. However most governments in the developing world, including South Africa have failed to acknowledge that most new urban informal settlements are developed by an illegal process as informal settlement residents willingly or unwittingly contravene planning regulations, contravene laws out of ignorance of the legal requirements, coupled with the inability to conform to the high standards set. Consequently, States respond to this illegality in the form of eviction as it threatens the economic, social and political stability of the urban environment. Concepts promoted internationally and identified in international literature recognize that the solution to informality lies in appropriate protection of rights which should ensure access to secure shelter leading to access to other benefits such as livelihood opportunities, public services and credits. That flowing from International Laws and Covenants, Human Rights Law needs to be looked at as a system of law that creates legally binding obligations for states with the aim of protecting, respecting and promoting housing rights for informal settlement residents. In the context of rights, Fernandes goes further in emphasising the legal constitutional perspective of the urban phenomenon where law is used as a vehicle for urban development and social change as well as encouraging state action and its attempts at socio-political legitimization in the context of informal settlement intervention.