The total urban area of each study site was calculated for each time slice and the results were represented as maps depicting urban expansion. Graphs were also created depicting the total urban area vs. total population for each time slice (1970s, 1990s and 2000s).

Bibliography: pages 97-102. / The assessment conducted in this dissertation was shaped by the intended formulation of an Integrated Coastal Zone Management Plan (ICZMP), as proposed by the Danish Co-operation for Environment and Development. An ICZMP provides an integrated and holistic approach to planning, in which the various activities and resource demands that occur within the coastal belt and neighbouring regions are appropriately coordinated. The first phase of the formulation of this management plan entailed the compilation of a baseline report summarising the present state of the environment in the study area, with particular emphasis on the major issues which will require attention in an ICZMP. This study was undertaken by Masters students from the Department of Environmental and Geographical Science at the University of Cape Town. The study area is located within the coastal belt of Namibia's Erongo Region, and more specifically within the magisterial districts of Swakopmund and Walvis Bay (Map 3). This includes the National West Coast Tourist Recreation Area and a portion of the Namib Naukluft Park. The southern boundary extends to the Sandwich Harbour, while the northern boundary extends to the southern bank of the Ugab River. The eastern perimeter is that of the Swakopmund magisterial district, and includes the municipal areas of Walvis Bay, Henties Bay and Arandis, together with Rossing Mine and its immediate environment. The seaward boundary is defined by the three nautical mile limit from shore. The Baseline Report: Coastal Zone Management Plan for the Erongo Region, Namibia was submitted to DANCED in March 1996. The findings of the investigation, as recorded in the report, highlight a number of issues which require urgent attention in the ICZMP. One such issue concerns the rapid influx of migrants to the urban centres in the study area. Population is a determining factor which significantly influences the functioning of other key sectors within a given location. As such, an understanding of the ramifications of increased population numbers is imperative to the formulation of an ICZMP. The objective of this dissertation was, therefore, to identify the factors generating rapid migration to the study area, and to facilitate an assessment of the impacts of this phenomenon. Once identified and assessed, these impacts can be better managed within a holistic, integrated framework.

Includes bibliographies. / Urban development and engineering works have resulted in the majority of rivers that drain urban areas being severely degraded, both ecologically and in terms of their potential amenity value. This dissertation explores the reasons for this "spiral of degradation" and it describes the ecological and social impacts on rivers caused by urban development, channelisation and canalisation. It then suggests possible measures to mitigate the impacts at the levels of the catchment, floodplain and river channel. The present cycle of degradation of urban rivers in the Cape Metropolitan Area (and elsewhere) can be halted. In addition, where degradation has already occurred, mitigation and rehabilitation are possible and could restore some of the lost conservation and ecological values, as well as the potential amenity, recreation and education functions. Early colonisation of Cape Town by Europeans inflicted severe impacts on the rivers surrounding and passing through the city. These included: catchment degradation, water abstraction, the disposal of unpurified sewage and industrial effluents, removal of riparian forests, clearing of instream vegetation and the draining of wetlands. During the 20111 century, many urban rivers have been "improved" by straightening or confining within rectangular concrete-lined canals in order to protect urban development in flood-prone areas. The unquestioning faith in technology during this period and the attitude that human ingenuity could "improve nature" are now regarded by the scientific community, together with some local and regional authorities and informed members of the public, as mistakes that resulted in ecological and environmental degradation. These technical solutions merely treated the symptoms of the problem without recognising, let alone attempting to treat, the causes, that is poor catchment and floodplain management. However, there is still a public demand for canalisation of the remaining "natural" rivers in the greater Cape Town area and beyond. At the same time, there has been an increase in environmental awareness, as well as a growing appreciation of the value of holistic and multi-objective planning in the engineering and planning professions. This dissertation aims to assess the impacts of urbanisation, channelisation and canalisation on the aquatic ecosystem and socio-economic environment of urban rivers, and to develop possible measures to mitigate these impacts.

Bibliography: leaves 86-92. / Quarry operations are only a temporary use of the land, while the environmental impacts associated with them are more long term. For this reason, it is unacceptable to merely abandon a quarry once operations have ceased. This study considers the role of rehabilitation in providing solutions for the disturbances caused by quarrying. The value of adopting a pre-planning approach towards rehabilitation is considered, and the components of a rehabilitation programme are identified. Using this information a rehabilitation checklist is drawn up. A survey of thirty rehabilitation reports, submitted to the Cape Town regional offices of the Department of Mineral and Energy Affairs, was undertaken using the checklist. Results of this survey indicate that rehabilitation reports are submitted merely to meet the minimum legal requirements contained in the Minerals Act of 1991 (Act No 50 of 1991). This study recommends that successful rehabilitation will only be achieved when rehabilitation reports function as effective working documents.

The use of genetically modified (GM) crops to resolve food security and poverty issues has been met with controversy and scepticism. The rationale for this research was to highlight the nuanced reasons as to why smallholder farmers are motivated to use agricultural biotechnology. The aim of this study was to explore the uptake of GM maize by South African smallholder farmers in order to contribute towards understanding the implications of agricultural biotechnology in smallholder agriculture. Using the case studies of Hlabisa in KwaZulu-Natal, the objectives were; (i) to investigate the perceived benefits and problems associated with the uptake of GM maize. (ii) to identify which institutional, political, social, and environmental factors influence the choices and decisions made by smallholder farmers to grow GM maize and (iii) to assess how GM maize has affected the well-being of farmers, including social cohesion in the farming communities. The reason Hlabisa was selected for the case study is that it represents one of the few areas in South Africa where GM crops (white GM maize in particular) has been cultivated on a long term basis by smallholder farmers. The necessary information was obtained through the means of a survey in which a number of farmers in the Hlabisa area participated in this regard the participants were; 40 farmers who used white GM maize that possessed the herbicide tolerant and insect resistant traits; seven farmers who used white insect resistant maize and 11 non-GM maize farmers. In addition, five key informant interviews and three focus group discussions were used to collect data. The history of agriculture in the area reveals that modern maize varieties were introduced when agricultural extension officers started operating in the area, beginning with maize seed hybrids in the 1970s. Maize hybrids were framed as better varieties compared to traditional maize in terms of performance. Later, in the 2000s, the seed company Monsanto, and the local department of agriculture introduced various GM maize varieties through farmers' days. This marked the addition of another institution providing so-called expert knowledge about maize farming in Hlabisa. It was argued that relationships between the local department of agriculture, farmers' associations and seed companies were instrumental in encouraging the uptake of GM maize seeds. It is also posited that the GM maize farmers in this study received pseudo-extension and advisory services. These had the agenda of promoting GM maize varieties over traditional varieties, relaying inappropriate agricultural knowledge in the process. There was also a lack of transparency in communicating the potential health and environmental risks associated with GM maize farming. Farmers were unaware that they were legally not allowed to save and exchange the patented GM maize seeds and had to plant refugia to prevent insect resistance. The uptake of GM maize has not significantly affected the seed saving and exchange practices of farmers. Fifty-two percent (24) of the 47 respondents no longer exchanged or saved any of their maize seeds in the study. A chi-squared test for independence indicated that the GM maize farmers were less likely to save and exchange seeds. The non-GM maize farmers were deterred from planting GM crops by the expensive input costs. The issue of affordability of the GM technology also extended to GM farmers, most of whom used social grants to purchase their GM maize seeds. Forty-nine percent of these farmers were in debt due to their uptake of the GM maize. Despite this debt, 74% of respondents claimed that they had perceived an improvement in their quality of life after using white GM maize, as they harvested enough maize to last them to the next planting season and were able to sell surplus maize. However, they only made marginal profits to cover household expenses. There are several conclusions that can be drawn from this study. First, there is a noticeable shift from farmers relying on their own knowledge and experience to using that of seed companies and agricultural extension officers. Second, Seed companies are beginning to fill the gaps left by public extension and advisory institutions and farmers are vulnerable to making uninformed decisions as they are not given relevant information. It is recommended that farmers are given agency through the provision of transparent information. This should be the responsibility of the government and not seed companies with vested interests. The government should try to move away from the idea that farmers need to scale up production through using modern varieties. A better approach would be the strengthening of appropriate support and extension services for South African smallholder farmers who use various maize systems. Lastly there is a need to raise awareness about the social, economic and environmental implications to farmers who elect to use GM seeds.

No description available.

Includes bibliographical references.

Bibliography: leaves 178-189. / The opportunities and constraints experienced in managing abutting urban and natural areas represent a microcosm of the issues facing future conservation practices. The focal areas for this study are Kommetjie and Ocean View -- two adjacent but insulated communities, that reflect basic socio-economic characteristics of South African cities, and situated amidst the natural areas of the Cape Peninsula. Current theoretical perspectives on natural and urban areas fail to offer a practical approach to inform integrated and equitable management of these ostensibly disparate realms of the environment. Although largely based in rural research, political ecology, which embraces a multidisciplinary perspective, promotes an integrated framework for managing adjacent urban and natural boundaries of the kind associated with the Cape Peninsula. Using conventional botanical methods, evidence in the case studies suggests that a relationship exists between environmental degradation in natural areas and the proximity of urban settlements. Moreover, the nature of environmental degradation seems contingent on the level of economic development of local communities. A social analysis of the communities reveals that co-operative management between landowners and key-players on either side of the boundary is similarly hindered by socio-economic factors. Using an adaptation of Blaikie's (1995b) "Chain of Explanation", the interactions between Kommetjie and Ocean View, and surrounding natural areas are integrated in an analysis which crosses disciplinary divides, and exposes the relationship between local environmental conditions and broader social issues. The boundary of a national park is not sufficient to manage the interactions between protected areas and neighbouring communities, but must be supported by partnerships between city and conservation authorities, NGOs, private landowners and residents in ways that address the needs of neighbouring communities. To facilitate local involvement in the management of the environment, residents, both rich and poor, must understand how the state of the environment directly affects their lives.

Includes bibliographical references. / [Fix subscripts in abstract.] The attractive image of Cape Town is threatened by periods of poor air quality occurring most often between April and September, during episodes of brown haze. When this haze occurs, it appears in the morning as a layer of concentrated pollution, likely to be associated with photochemical pollutants such as tropospheric ozone (O3) and some of its precursors. Previous studies have identified local emission sources and meteorological conditions associated with both the air pollution and the brown haze in Cape Town. However, due to the transport of air pollutants, emissions from remote sources may also contribute to air pollution levels in Cape Town. This dissertation investigates the local variation and the regional-scale transport of atmospheric pollution over Cape Town, with a focus on O3 pollution. The study analyses O3 observations from local air quality stations and uses two atmospheric chemistry-transport models to simulate the photochemical pollution over southern Africa.

Bibliography: leaves 77-84. / A technique employing the classification capabilities of the Kohonen self-organising map (SOM) is introduced into the body of computer-based techniques available to synoptic climatology. The SOM is one of many types of artificial neural networks (ANN) and is capable of unsupervised learning or non-linear classification. Components of the SOM are introduced and an application is then illustrated using observed daily sea level pressure (SLP) from the Australian Southern Hemisphere data set. To put the technique in the context of global climate change studies, a further example using simulated SLP from the GENESIS version 1.02 General Circulation Model (GCM) is illustrated, with the emphasis on the ability of the technique to highlight differences in seasonality between data sets. The SOM is found to be a robust technique for deducing the modes of variability of map patterns within a circulation data set, allowing variability to be expressed in terms of inter and intra-annual variability. The SOM is also found to be useful for comparing circulation data sets and finds particular application in the context of global climate change studies.