Cut-off lows (COLs) are an important rainfall source in the Western Cape. While several studies have examined the devastating impacts of COLs during extreme rainfall events, little is known about the characteristics of COLs during droughts and how the characteristics are influenced by the South African complex topography. This thesis investigates the interannual variability of COLs and COL precipitation over Western Cape, with a focus on the 2015 - 2017 drought that affected the region and examines how well climate models simulate the variability. It also studies how the complex topography of South Africa influences the COLs characteristics. Four types of datasets (observation, satellite, reanalysis, and simulation) were analysed for the thesis. The observation, satellite and reanalysis data were analysed from the period 1979-2017, while two simulations were performed using a regional climate model (called WRF) and a variable grid model (called MPAS) for the period 2007-2017. A COL tracking algorithm was used to extract all the COLs that occurred in the vicinity of the Western Cape during the study periods. The Self Organising Map (SOM) was used to classify the COLs into groups based on their precipitation patterns. The upper-air data was analysed to study the characteristics of the COLs in each group. To examine the role of topography on COLs, WRF was applied to simulate three COLs over real and three idealised terrains (i.e. "no topography", "only-west-topography" and "only east topography"). The results show that, on average, the Western Cape experiences 10 COLs per year and the COLs contribute about 11% of the annual precipitation over the province, although with a large interannual variability. In 2015 and 2016, the COLs occurred more frequently than normal, with more than normal precipitation contribution, thereby reducing the drought severity in the two years. Contrarily, in 2017, the COL frequency and precipitation contribution were less than normal, because COLs were mainly seen further south. Nevertheless, we found that an increase in annual COL frequency does not always lead to an increase in the annual COL precipitation, because the COLs produce different amounts of precipitation. More than 45% of the COLs over the Western Cape produces little or no precipitation. The SOM results reveal that the spatial distribution of COL iv precipitation can be grouped into four major patterns. The first pattern indicates precipitation over the entire Western Cape while the second shows little or no precipitation; the third and fourth patterns feature precipitation over south-east coast and south-west coast, respectively. The major difference between the first pattern (i.e. wet cols) and the second pattern (dry COLs) is that while the wet COL is associated with a southward transport of warm and moist tropical air towards the Western Cape, the dry COL is not. Hence, the contrast between the warm and cold air mass is weaker in dry COLs than in its wet counterpart. The models (WRF and MPAS) capture the seasonal and annual climatologies of COLs and their precipitation. However, they do not always capture the inter-annual variability, with WRF outperforming MPAS in general and during the drought period. Both models represented all the COL precipitation patterns well but under-estimated the frequency of dry COLs throughout the seasons. However, the models were able to simulate the general observed differences between dry and wet COLs. WRF simulation shows that topography influences the precipitation, track, formation and vertical structure of COLs. Topography provides the additional forcing needed for COL formation. The results of this study may be applied to improve monitoring and prediction of extreme rainfall events over the Western Cape.

Includes bibliographical references. / Table Mountain is an inherently physical and natural landscape that also holds deep cultural meaning, symbolism and value for generations of Capetonians, past and present. The first detailed accounts and artistic representations of Table Mountain come from the early European discoverers, sailors and colonists who travelled to the Cape. These visitors, prejudiced by imperial rhetoric, were polarised in their perceptions of the Mountain between those who viewed it as a heavenly paradise and others who considered it a hellish purgatory. When science and logic eventually subdued the myths and mysteries associated with the ‘Dark Continent’ of Africa the polarised conception of Table Mountain’s cultural landscape was transformed into one of savagery and opportunity. indeed, from the sixteenth to eighteenth century, Table Mountain was effectively a microcosm for European attitudes, assumptions and evaluations of Africa. In the 1990’s Table Mountain's cultural meaning is still divided between those who seek to conserve and preserve its natural and spiritual integrity and those who believe that utilising the Mountain’s landscape as a material asset is the best means for ensuring and justifying its survival. A post-modern perspective highlights the broad range of economic, spiritual, ecological and community based values the Mountain holds for Capetonians and South Africans in general. Set against this viewpoint, Table Mountain, under the structured management of South Africa National Parks, is increasingly becoming a modernist cultural landscape governed by principles of universality, order and control. The ideological clashes that arise from these contrasting interpretations of the Mountain result in the defining characteristic of Table Mountain’s cultural landscape in the 1990’s being one of conflict and reproach. Ultimately by marrying the local and nationalised concepts within the South African landscape tradition to the broader frameworks of landscape study in wider geography, this thesis formulates an eclectic approach to studying a deeply meaningful and complex cultural landscape.

Bibliography: leaves 84-90. / This dissertation is concerned with the question of local resource use. It explores this question and more specifically common property resource management regimes using Skoonheid Resettlement Project in the Omaheke Region in Namibia as a case study. This study was born out of a Retrospective Assessment of the Environmental Implications of Resettlement in Namibia, commissioned by the Namibian Programme to Combat Desertification (NAPCOD) through the Namibian Ministry of Environment and Tourism (MET).

Bibliography: p. 103-107. / Contract No. LHDA (Lesotho Highlands Development Authority) 1000 is the design and construction of the supporting infrastructure for the Mohale Dam, Phase lB of the Lesotho Highlands Water Project (LHWP). The Environmental Evaluation Unit (EEU) of the University of Cape Town (UCT) was employed by GBJV (Gibbs-Bergman Joint Venture), consulting engineers, to conduct the environmental impact assessments for contract No. LHDA 1000. The impact assessments were: * an initial EIA of the Maseru bypass alternatives; * an EIA of two site access roads at the Mohale Dam construction site; * an EIA of the Resident Engineers Camp, and * an EIA of the Least Cost Alternative Route (LCAR) and the Western Access Route (WAR) for the transport of construction materials to the Mohale Dam site. The WAR, which forms part of the existing Mountain Road, was identified as a viable option for the transport of construction materials to the Mohale Dam site. The LCAR was identified from eight alternatives, excluding the WAR, in an initial desk-top study, as a viable route. The WAR proposal involves the upgrading part of existing Mountain Road, which runs in an easterly direction from Maseru, over the Thaba-Putsoa Mountain Range to ThabaTseka. The WAR proposal would upgrade 60 km of this presently degraded road between St. Michael's and Patiseng. The LCAR runs from Maputsoe to Ha Mateka via Teyateyaneng along existing roads. 55 km of new road will be built through the Jorodane Valley from_ Ha Mateka to Mafotholeng (refer to Map 1). Two separate baseline EIA reports were produced for the LCAR and the WAR proposals.

Includes bibliographical references. / The modulation of Tanzanian coastal rainfall variability with the El Nino/Southern oscillation (ENSO), the largest known mode of Southern Hemisphere climatic variation is examined. A rainfall index was formulated from variable Tanzanian coastal stations and used to identify the rainfall characteristics of each ENSO year. Monthly anomalies of selected meteorological fields were analyzed for El Niño/La Niña composites and each individual event to determine the mechanisms associated with seasonal rainfall over teh Tanzanian coast during ENSO years.

The Thermal internal Boundary Layer (TIBL) is a dynamic and turbulent mesoscale feature of the coastal atmosphere that forms over the land during conditions of onshore flow. The TIBL develops as an adjustment of the atmospheric boundary layer to the discontinuities of temperature and roughness that occur at the interface between the underlying marine and terrestrial surfaces. The resulting formation of a characteristically convex mixed layer below relatively stable air aloft has serious implications for the dispersion of pollutants in shoreline environments. Although a wide range of research relating to various features of the TIBL may be found in the literature, relatively few broadly-based studies have been performed. This study has employed both airborne and surface measurements to obtain a comprehensive spatial and temporal data set, in order to elucidate aspects of the characteristic structure and behaviour of the TIBL. TIBL growth was found to follow a diurnal pattern, the initially irregular boundary becoming more uniform during the day as a steady balance between various factors was achieved. The TIBL was associated with a layer of uniform wind speed anti direction flowing perpendicular to the coastline, within which warmer temperatures and changes in relative humidity and moisture content were observed. The temperature structure of the onshore flow strongly influenced the intensity of turbulence encountered in the TIBL and the degree of entrainment aloft. Patterns of turbulent properties displayed significant increases in the TIBL, which were relatively abrupt near the surface and more gradual towards the top of the TIBL. Measurements of sensible heat flux revealed strong undulations in TIBL structure due to transitory eddies and thermal upcurrents. Certain theoretically based predictive equations of TIBL height displayed the best overall performance out of eight selected models, and some promise was shown by an empirical formulation. TIBL development was generally complex and irregular within the first few kilometres of the shore, while further inland more regular TIBL formation enabled the relatively accurate observation and prediction of TIBL height.

Includes bibliographical references (leaves 101-113). / Seven decades ago, the pre-eminent limnologist, Miss Edith Stephens described the Cape Flats as "a paradise for the aquatic biologist". At that time the area was characterised by numerous temporary or seasonal wetlands that filled and dried in concert with the seasons. Since Miss Stephen's observations, the number of seasonal wetlands on the Cape Flats has dwindled alarmingly and very few remain. This dissertation attempts to account for this and provide guidance for the management of the remaining seasonal wetlands. The dissertation shows how development (characterised by the urban and agricultural land-use) has radically altered the nature of seasonal wetlands and that Typha capensis can be used as an indicator of the ecological value or integrity of these wetlands. Two case studies have been selected to test this premise. The various interrelationships between vegetation, hydrology, nutrients, land-use and ecological value are explored and the proliferation of wetland communities of Typha capensis is shown to be an indicator of negative impacts on seasonal wetlands. The literature review indicates that the proliferation of Typha capensis signifies a decline in habitat diversity and biodiversity (species richness). Typha capensis has been shown to be influenced by streamflow and nutrient input (the plant thrives in shallow areas, permanently inundated with nutrient-rich waters). Therefore, changes to the total area occupied by Typha capensis can be used to illustrate how development has affected the hydrology, habitat diversity, biodiversity and ecological value of seasonal wetlands. The primary source of information was aerial photography, of varying scales, dated from the early 1940s to 2000 and acquired from the Department of Land Affairs: Land Surveys and Mapping. Identifying, mapping and interpreting land-use changes and changes to Typha capensis formed the basis of the research. Water chemistry information, obtained from the Scientific Services Department of the City of Cape Town, and an extensive literature review supplemented the photographic information. Zeekoevlei / Rondevlei wetland and the Khayelitsha wetlands are used as case studies. Together they have been affected by a significant range of impacts generated by different manifestations of development including Wastewater Treatment Works, high-income residential areas, catchment hardening, manipulation of drainage patterns, informal settlement, informal grazing, agricultural runoff and horticultural market gardens. The pattern of land-use change within the selected wetlands' catchments (Lotus River catchment and Kuils River catchment), the impacts of the observed land-use changes, and the impacts to Zeekoevlei / Rondevlei and the Khayelitsha wetlands with respect to seasonality, Typha capensis and ecological value are presented and discussed in detail. In general, urban areas have increased over time to dominate the two catchments. Agricultural areas were consolidated into a few areas while the areas of open space diminished rapidly. Surface and stormwater runoff from "hardened" catchments, irrigation of farmland, and treated effluent from Wastewater Treatment Works all drastically increased, In addition, the concomitant influx of nutrients (nitrates, nitrites and phosphorus) polluted the rivers and wetlands, making them eutrophic and promoting the proliferation of large stands of Typha capensis. The impact of these changes was the loss of seasonality, habitat diversity and biodiversity. Specific recommendations are made for the long term management of Zeekoevlei, Rondevlei and the Khayelitsha wetlands. The proposed management strategy is based on selected management objectives i.e. what is the wetland being managed for? It might not be possible to fully rehabilitate them to a pristine state but management as recreational areas, conservation areas and even educational areas is possible. Key points of the recommended management plans include: * maintaining the winter drawdowns at Zeekoevlei / Rondevlei; * implementation of a dredging and Typha clearing programme; * strategically placed reed beds to purify inflow; * a fire programme for the Khayelitsha wetlands; and * instating an environmental awareness course at the Khayelitsha wetlands. The importance of an Integrated Catchment Management Plan is emphasised. Catchments should be managed as a whole, recognising the relationships between planning, land-use and water resources.

Bibliography: leaves 126-134. / In 1998, after spending ten years in government business, as an economist in Tanzania, four of which in departments/ministries dealing with environmental and natural resources management in the country, I made a decision to study Environmental Science. This was triggered by the fact that I noticed there is a dearth of Environmental and Resource Economists in my county. I realised that most politicians and technocrats were paying lip service to environmental problems, and could not link environmental management issues with economic development policies and strategy.

Includes bibliographical references. / The small-scale mining (SSM) sector in South Africa has been overshadowed by the wealth generating capacity of the formal mining industry. To address the disparity between the SSM sector and the large formal mining industry, a number of government initiatives have been introduced, the latest being the preparation of the Minerals and Petroleum Resources Development Act 28, which was finalized in October 2002. The Act, which has not yet been implemented, is expected to redress some of the sector's current obstacles. Two case studies conducted in the Northern Cape and North West Provinces, provided the basis for this social impact assessment (SIA). The aim of these studies was to identfy the most serious issues faced by the SSM sector and to assess the likely socio-econiomic impacts of the Act.

Includes bibliographical references (leaves 107-117). / This thesis examines the feasibility of applying people-centred approaches to flood early warning systems (EWS) in informal settlements in the City of Cape Town, particularly, through the experiences of poor and disadvantaged communities in Kosovo and Masiphumelele informal settlements. The impact of recurrent floods during the winter rainfall months and their costs are disproportionally borne both by those at risk and the local government that is required to repeatedly respond to them. A social science perspective is adopted, with the application of a risk communication framework. The urban flood-risk context of both study sites and the risk governance approach to managing and communicating flood risk were investigated and factors influencing flood warning processes and behavioural factors influencing response to flood-risk and flood warning, examined.