The premise of the thesis is that the developmental use of urban land should be ethical, fair and promote social justice. Using multiple research approaches and mixed methods this thesis examines the urban land question in South Africa and particularly Cape Town where land distribution and ownership are inequitable. The thesis unpacks land redistribution, land tenure reform and land restitution within this context. It is argued that the South African Constitution commits government to protect the property rights of those who currently own property and at the same time redistribute land to those who have been dispossessed and explores what this tension means for urban land redistribution and reform using the freedoms approach developed by Amartya Sen as a conceptual framework and as alternative to the neo-classical model. The main findings of the thesis can be summarized as follows. a) The thesis demonstrates that there is no logical reason why the freedoms approach cannot be extended to include urban land. b) The entitlements and endowments that urban land could bestow on the urban poor are shaped by how the State invests in land through the instruments of land planning and land use management which call for a significant role for the State as custodian of public land to not only make explicit the land asset register under public ownership but also instill trust in the poorer sectors of urban society. c) A two track system of land planning and land use management may be more appropriate in the post apartheid South African city, one stream for market driven land and one for targeted public land programmes that directly address urban poverty provided that the State is able to make strong connections between the philosophical and the technical aspects of land and land use management systems. d) As a two track system is suggested the land use management system requires to be reframed. To facilitate land redistribution and reform in urban areas of South Africa therefore, the thesis suggests that a deliberative and systemic planning approach needs to be adopted that is intervention focused. Only when the State assumes a more critical interventionist role in public land programmes would it be possible to obtain social justice and the principles of the good city in the South African urban context. e) Gaining access to and control over land resources beyond the market is possible but limiting for the majority of the urban poor when land and housing debates are conflated. This conflation results in other land debates being silenced yet these have the potential to offer alternatives to the neo-classical model of land and land use management as well as promote a wider role for public land than just housing.

Includes abstract. / Includes bibliographical references. / Like many of the world’s subtropical regions, the Western Cape of South Africa is highly sensitive to oscillations in the earth’s climate system triggered by major tectonic changes, local variations in orbital forcing, better known as Milankovitch cycles, and its position at the interface between temperate and tropical circulation systems. Regrettably, a dearth of reliable and continuous palaeoenvironmental records means that relatively little is known about how regional environments have been impacted over centennial to multi-millennial timescales. Palaeosols constitute an important stratigraphic marker for past environments and may provide useful validation of pedogenic and other earth system process models. However, the characterisation and analysis of palaeosols has been a largely neglected source of information in the Western Cape, South Africa. This thesis aims to improve the understanding of the environments and climate dynamics using evidences from palaeosols. Various palaeosol-based proxies including geochemistry, mineralogical, macro- and micromorphological, δ13C and δ18O isotope, and selected physico-chemical properties of palaeosols were studied and records obtained for four sites in the Western Cape. A number of chemical weathering indices and geochemical climofunctions were used to calculate weathering intensities, pedogenesis, palaeotemperature and palaeoprecipitation for the various locations using geochemical and stable isotope data. Results of this study indicate that palaeosol-based proxies have the potential to provide snapshots into the palaeoenvironments and palaeoclimate of Western Cape and may complement previous studies done with other proxies such as pollens and diatoms. For example, the interpretation of the pedofeatures (calcareousness, vertic, gleyic, illuviation) - from the micromorphology - of thepalaeosols suggests cyclic patterns of erosion and deposition that correlate with climate changes of the past. Podzolization and laterization are the principal pedogenic processes responsible for the red palaeosol formation at the Cape Peninsula, while calcification and salinization are accountable for the Quaternary palaeosols. Inferences of gleization and lessivage are only evident in the mid-Miocene palaeosol at Langebaanweg. At LBW, pedogenesis was more advanced in the Mid-Miocene and Early Pliocene layers signifying a more humid and warmer climate with more stable landscape. Two major regional climate cycles were evident at the Cape Peninsula: relatively warm and humid subtropical climate which gave rise to the pedogenically modified buried red palaeosol and dry semi-arid Mediterranean climate under which the soils overlying the stone line is currently forming, as seen from the poor horizonation and translocation of materials. Clay mineral assemblages suggest the Quaternary palaeoclimate of the Western Cape has been predominantly characterised by low precipitation and active coastal erosion, which jointly accounted for poor soil profile development. This is in agreement with the early reports obtained from marine records of the African continent (e.g. deMenocal, 2005). A cross plot of the δ13C and δ18O of the carbonate palaeosols indicates they all formed under strong marine influence and C3 plants have been dominant since late Quaternary.

Includes abstract. / Includes bibliographical references (p.127-131). / Global Circulation Models (GCMs) are the primary tool for simulating future climate changes. These models by necessity make use of various assumptions and simplifications due to computational constraints, and in so doing introduce biases and systematic error. Along with other sources of uncertainty regarding our understanding of the climate system and given the quasi-chaotic nature of the climate, climate projections differ between models whose climate simulation skill is poorly quantified. A new methodology is presented to assess the regional biases in GCMs and to, in part, compensate for some aspects of these biases. The study will focus on the Southern African region but could be replicated for other regions. Using Self-Organising Maps (SOMs), synoptic archetypal patterns are identified and the distribution and frequency of these patterns assessed. The use of synoptic archetypes to quantify model metrics presents a novel approach with many benefits over standard metrics, such as errors and means per variable. SOMs add a spatial and multi-variable dimension to the analysis as each metric is calculated based on its synoptic circulation pattern and associated to a set of atmospheric variables. Some persistent biases in the models are notable based on comparisons between the NCEP and GCM SOM node mapping, such as an overall cool bias in the models and a shift of the dominant high pressure cells and thus the westerly wave to the south. The weighting techniques provide insight into how much of the model bias is contributed by differences in synoptic frequency and what part is attributable to systematic biases in the models which result in a different mean state for a given synoptic process. The frequency correction enabled a correction of up to 25% of the difference between model and reanalysis data, but in most cases the change was far smaller than this. The differences in mean conditions remained the largest component of the bias. To correct for this the weighting was applied to the climate change anomaly (difference between future and control projections) per synoptic process to create a multi-model climate change component that is added to the NCEP baseline. This provides the most accurate depiction of future climate from the data provided. The models generally have different strengths, therefore the weighted multi-model solution allows models to give a greater contribution where they are skilful and less where they do not match the observed dynamics. Comparison of the magnitude of the climate change signal showed that winter states in the weighted multi-model composite had a smaller temperature increase and reduced rainfall compared to the unweighted results. In summer states there is greater warming and increased rainfall, especially over the oceans. This suggests the models are over estimating changes in temperature in winter and underestimating the increases in summer. Synoptic events are the primary driver of climate change impacts. Therefore errors in synoptic state will have a notable influence on the climate change projections and need to be fully considered in any climate change impact study. The use of the weighting technique helped to identify and reduce uncertainties in the climate change projections over Southern Africa.

Includes abstract. / Includes bibliographical references. / Lagrangian moisture source attribution model is developed in order to explore the regional moisture source dynamics of southern Africa. In particular, the model was developed in order to explore the role of the regional land surface as a source of moisture for regional precipitation. This work was prompted by previous studies suggesting that the land surface may play an important role in the regional climate system and particularly in the regional hydrological cycle. Existing moisture transport and source methodologies have a number of limitations.

Climate change studies are subject to high uncertainties partly resulting from data reliability. This study investigates the challenges of using statistical downscaled climate data to examine the likely impacts of climate change on maize growth in southern Africa in the context of these uncertainties.

Includes abstract. / Includes bibliographical references (leaves 215-241). / The study is focused on four study sites, two in the Western Cape, namely the Bruno section and Lake Michelle and two in southwestern Australia, namely Wambellup Swamp and Devil's Pool. These sites were chosen as they are well situated to investigate the complex interaction between Late Quaternary climate change, the influence of fluctuating sea levels and the impact of human interaction with the environments in question and provide a regional picture of these interactions.

Word processed copy. / Includes bibliographical references (p. 219-236). / This study investigated the causes, magnitude and selected socio-ecologlcal effects of soil degradation, with the ultimate goal of explaining and mapping the spatial and temporal variations of degradation in the dryland area of central Uganda.

Word processed copy. Includes bibliographical references (leaves 235-255).

Bibliography: leaves 182-189.

Includes bibliographical references (p. 111-119).