3. Electronic Theses and Dissertations (ETDs) - All submissions
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Item The deterioration of the life support base: the perceptions of people in informal settlements towards limiting pollution in their environment(2008-08-28T12:07:31Z) Mporetji, SimonDiepsloot, a township in Johannesburg, South Africa, was used as a case study to explore the perceptions of people in informal settlements towards their role in limiting pollution in their environment. The method followed was qualitative, and primary data were collected through the use of key informants (Ward Councillor and Environmental Health Officer), and three focus groups. Diepsloot is a marginalised residential area located in the Northern perimeter of the City of Johannesburg. The settlement is spatially fragmented, reflects a high residential density and is plagued with high levels of unemployment and poverty. Compounded by poor municipal service delivery, these challenges lead to a range of environmental problems such as overflowing solid waste on the streets, water pollution, and high levels of indoor air pollution. The study found that there were varying levels of commitment to limiting pollution by people in the informal settlement. This (commitment to limiting pollution) was largely dependent on community action through the formation of street committees. In streets where there was community cohesion, street committees were stronger and environmental conditions were better. In contrast, environmental problems were worse where street committees were weak or not operating. Regarding the role of government, the major constraints leading to unresponsive interventions were the limited scale of municipal operation and their poor communication with residents. Suggested corrective measures include recycling, education on pollution and the need for institutional strengthening. Further research aimed at identifying a set of appropriate partnerships and institutions needed for responsive interventions in informal settlements is required.Item Characterisation of Cape Town brown haze(2006-11-16T12:13:23Z) Walton, Nicola MariaThe Cape Town brown haze is a brown-coloured smog that is present over the Cape Town atmosphere during the winter months due to the accumulation of gaseous and particulate pollutants. The main aim of this research was to evaluate the impact of atmospheric pollutants to visibility impairment by the brown haze through visibility modelling of major pollution sources around the City of Cape Town. The screening model, VISCREEN, the Plume Visibility model, PLUVUE II and the CALPUFF Modelling System were employed to model the visual impact of emissions from the major sources. Two point sources, Caltex Oil Refinery and Consol Glass, and three area sources, Cape Town Central Business District (CBD), Cape Town International Airport and the townships of Khayelitsha and Mitchell’s Plain were identified as the major sources. An initial screening analysis indicated that emissions from the two industrial sources would be visible and would result in a yellow-brown discolouration of the atmosphere. Detailed modelling using PLUVUE II identified the area sources of Cape Town CBD and the townships to be the significant contributors to visibility impairment over Cape Town. Plume perceptibility is primarily dependant upon particulate emissions while NOx emissions influence the colouration of the atmosphere. CALPUFF was employed to assess the distribution of NOx, SO2 and PM10 concentrations over the area and the associated visibility impairment on a nonhaze (13 August 2003) and haze day (22 August 2003). Pollutant concentrations were considerably reduced on the non-haze day compared to the haze day. The Cape Town CBD was an important source of all the major pollutants with the townships contributing significantly to the aerosol loading over Cape Town. Pollutant concentrations are particularly elevated during the late evening and early morning periods, particularly between 7 am and 8 am. Visibility impairment is greatest on the haze day, particularly over the central Cape Town region and the townships. The greatest reduction in visibility is experienced between midnight and 9 am which corresponds with the periods of elevated atmospheric pollutant concentrations.