To assess the skill of seasonal wind prediction in South Africa, the period between 1983 and 2018 was studied, unless otherwise stated. A total of sixteen (16) sites were studied across South Africa to ensure that each region across the country was represented in the study. Seasonally, prediction of the wind energy resource is important in order to plan for local plant operations, such as downtime for maintenance during low wind periods. Additionally, if a forecast indicates a large wind energy resource for a particular season, maintenance at other non-wind energy generation plants may be planned. However, currently there is limited information about seasonal prediction of wind in South Africa and no information about the skill of such a forecast. This thesis begins the process of addressing this knowledge gap. Correlations between the CFS hindcast data and the reanalyses show the windspeed forecast is skilful over the southern regions of South Africa during December – January – February (austral summer), and over northern regions during June – July – August (austral winter), where the Pearson Correlation Coefficient ranges between ~0.5 and ~0.75. This skill is a function of the regional atmospheric stability during the respective seasons which are in turn a function of large-scale circulation features that govern synoptic processes driving the regional wind predictability. La Niña results in a weakening of the high pressure systems to the west of the country, which could cause lower wind speeds specifically over the north-western regions of South Africa. The deepening of an extended sub-tropical low pressure trough over the interior of South Africa during La Niña potentially causes an increase in the pressure gradient, resulting in higher wind speeds over the eastern, north-eastern and eastern interior regions. During La Niña events literature indicates that the south-easterly wind speeds over regions of the Western Cape increase, and this could be due to the southward movement of the South Atlantic High Pressure. During a negative SAM phase, the correlation between the SAM Index and the reanalyses indicates that there is an enhanced predictability in the eastern interior regions of the country, specifically during September – October – November(where the r-value is < -0.4 over specific regions), which is likely a function of the strong belt of westerly winds that move equatorward and therefore closer to South Africa. A low-pressure trough develops and extends across the central interior of country which results in an increased pressure gradient between the interior and the high pressure cells off the coasts of South Africa, resulting in increased wind speeds over the majority of the country. These results indicates that ENSO and SAM are drivers of wind predictability over South Africa at the seasonal scale. The CFS hindcast captures the ENSO forcing (El Niño, neutral and La Niña) of wind speeds for the majority of the same regions and seasons as found in the reanalysis data. However, the CFS does not capture the SAM forcing of seasonal wind speeds described above. Therefore the CFS forecast system is a useful system with respect to seasonal wind forecasts given the ENSO forcing is captured, however, this study recommends that model development research should focus on developing forecast systems that capture other large-scale drivers, apart from ENSO, such as the SAM. The study also demonstrates that it is essential to use multiple reanalyses if assessing the skill of the seasonal forecast using reanalysis products. Results show that there are statistically significant differences between the reanalysis wind datasets. The ERA5 wind speeds were lower in the majority of the sites (14 out of the 16 sites) in comparison to the ERA-Interim and CFSR wind speeds. This indicated that when only one reanalysis was used, it could artificially show higher or lower skill levels. Based on the results above, this study concludes that there is better predictability in the CFS when the atmosphere is stable, and in certain parts of the country under La Niña and negative SAM during specific times of the year; for example, ENSO has greater effect over South Africa during austral summer months. During these skilful periods, the seasonal prediction system can be used to inform seasonal wind energy potential across the country. Understanding when and where a wind forecast is skilful could assist in efficient energy supply planning, inform plant operations such as maintenance and contribute towards the shift to a low carbon economy.

Climate change is seen to be playing an increasingly key role in determining the level of food security within Kenya. In 2020, around 3.1 million people in the country faced acute food insecurity as a result of excessive rainfall, flooding and drought. There has also been a concentration of research on major crops, such as maize and common bean. This study, therefore, seeks to contribute to the research gap in future projections of crop suitability for major and minor crops in Kenya. Temperature and rainfall data, downloaded from CORDEX, from four statistically downscaled Global Climate Models (GCMs) under the Representative Concentration Pathways (RCP) 8.5 and 4.5 were used to run the Ecocrop model. The output was the suitability index spatially plotted over the country for maize, finger millet, common bean, broad bean and sweet potato, within three time periods: historical (1980-2009), near term (2010- 2039) and midcentury (2040-2060). To further understand the influence soil pH has on the climate suitability of these five crops, QGIS was used to overlap Ecocrop suitability outputs and Soilgrids soil pH rasters. CORDEX projections indicated a 2°C- 2.5°C and 1°C rise in temperature under RCP8.5 and 4.5 respectively, and rainy seasons becoming more intense and shorter. The suitability index of maize is projected to have a slight increase (20%) during the long rains, by the end of the century under RCP8.5. Along the RCP4.5 pathways, there is a greater increase in suitability for maize in counties along the coast and western Kenya. Results also project a significant suitability increase (50%) of the orphan crop- broad bean- during the dry season. The spatial distribution of suitability is widespread within many arid and semi-arid counties. This presents an opportunity to integrate legumes such as broad bean into the cropping system within a crop rotation with maize. This form of adaptation would help ease the pressure on the production of staple crops since suitability for maize and common bean is projected to decrease during the short rains. Soil pH results indicated the dominance climate has on determining overall suitability. For instance, pH suitability of finger millet was achieved in majority of the counties however, climate suitability does not favour the planting of this crop. For sweet potato, there is optimum pH and climate suitability, however, it is not greatly distributed around the country. Despite the low spatial distribution, these small areas of sweet potato production can also contribute to better food security in these counties.

Climate change possibly intensifies hydrological droughts and reduces water availability in river basins. Despite this, most research on climate change effects in southern Africa has focused exclusively on meteorological droughts. This thesis projects the potential effect of climate change on the future characteristics of hydrological droughts in the Limpopo River Basin (LRB). The study uses regional climate model (RCM) measurements (from the Coordinated Regional Climate Downscaling Experiment, CORDEX) and a combination of hydrological simulations (using the Soil and Water Assessment Tool Plus model, SWAT+) to predict the impacts at four global warming levels (GWLs: 1.5℃, 2.0℃, 2.5℃, and 3.0℃) under the RCP8.5 future climate scenario. The SWAT+ model was calibrated and validated with a streamflow dataset observed over the basin, and the sensitivity of model parameters is investigated. The performance of SWAT+LRB model was verified using the Nash-Sutcliffe efficiency (NSE), Percent Bias (PBIAS), Root Mean Square Error (RMSE), and coefficient of determination (R2 ). The study also examines the capability of the CORDEX SWAT+ system in reproducing the hydro-climatology and the influence of the quantile delta mapping (QDM) method on bias correction of CORDEX datasets. The Standardized Precipitation Evapotranspiration Index (SPEI) and the Standardized Precipitation Index (SPI) have been used to detect meteorological droughts. The Soil Water Index (SSI) has been used to define agricultural drought, when the Water Yield Drought Index (WYLDI), the Surface Run-off Index (SRI), and the Streamflow Index (SFI) have been used to characterize hydrological drought. The performance of SWAT+ the model simulations over LRB is sensitive to the parameters CN2 (initial SCS runoff curve number for moisture condition II) and ESCO (soil evaporation compensation factor). The best simulation is generally performed better during the calibration period than in the validation period. In calibration and validation periods, NSE is ≤ 0.8, while PBIAS is ≥ ﹣80.3%, RMSE ≥ 11.2 m3 /s and R 2 ≤ 0.9. Although the CORDEX simulations capture the general spatial and temporal distribution of the hydroclimate variables over the LRB, they feature a cold and wet bias across the basin. However, the QDM bias correction reduces the bias and fosters better agreement among the simulations. The simulations project in all hydrological variables is projected over most parts of the basin, especially over the eastern part of the basin. The simulations predict that meteorological droughts (i.e., SPEI and SPI), agricultural droughts (i.e., SSI), and hydrological droughts (i.e., WYLDI, SRI) would become more intense and severe across the basin. SPEI-drought has a greater magnitude of increase than SPI drought, and agricultural and hydrological droughts have a magnitude of increase that is part-way between the two. As a result, this research suggests that future hydrological droughts over the LRB could be more severe than the SPI-drought projection predicts but less severe than the SPEI-drought projection. This research can be used to mitigate the effects of potential climate change on basin hydrological drought.

Includes bibliographical references (leaves 114-121). / Late Quaternary vegetation and palaeoenvironments are relatively easy to reconstruct in humid regions as polled traps (swamps and peat bogs) there are usually abundant. However arid and semi-arid regions (such as southern Africa) lack fossil pollen because of the scarcity of pollen preserving bodies. This attribute results in difficulties in palynological studies regarding the late Quaternary vegetation and palaeoenvironmental resconstruction in arid and semi-arid regions. But the advent of pollen analysis of fossil faunal dung middens in arid and semi-arid areas has enabled palaeoenvironmental reconstruction and interpretation in places where this could not otherwise have been easy. This project is based on pollen analysis of hyrax (Procavia) dung middens for the reconstruction and interpretation of vegetation history in the Western Cape Province, South Africa, thus filling the void of inadequate palaeoenvironmental records in semi-arid southern Africa.

Includes bibliographical references (p. 119-123).

Includes bibliography. / The popular use of the term sustainability represents a consensus around the fact that society must change its path towards ecological destruction and the consequent decline in human's quality of life. Sustainability facilitates the integration of environmental issues, previously seen as radical and disruptive, into mainstream political, social and economic discourse. The term therefore represents a transitional tool which will lead society from its current non-sustainable phase to greater sustainability. At present the most successful action for change is being initiated from the local level through local sustainability planning. Sustainability planning represents an alternative approach to local government decision-making based on the principles of sustainability. Many countries are experiencing success with local sustainability planning initiatives such as Healthy Cities and Local Agenda 21. These initiatives represent generic approaches to sustainability planning. This thesis contends that a more successful approach could be gained through tailoring strategic planning to local contexts. The challenge is to design a framework that meets the needs of the specific socio-economic, legislative and institutional contexts of a given area. South Africa's discriminatory socio-political history has resulted in major social and environmental legacies, especially amongst the marginalised and poor sectors of society. These legacies must be understood and addressed in order to carry-out successful sustainability planning processes. Since 1994 sustainability in South Africa has received significant attention in the legislation which has emanated from the democratic government. The legal framework for sustainability is provided by a progressive Constitution [Act 108 of 1996]. The Constitution provides clear objectives for environmental management. Furthering the framework for environmental management set out in the Constitution is the National Environmental Management Act [Act 107 of 1998] (NEMA). NEMA is a key piece of legislation which has far-reaching implications for sustainability. It establishes general principles which act as a framework within which environmental management in the country will be carried out. The Constitution [Act 108 of 1996] also sets out clear objectives for local governance. Local government in the CMA, as in the rest of South Africa, is suffering from the effects of the (re)current restructuring period following the country's transition to democracy. This sphere of government is experiencing significant financial and capacity constraints. The situation has been compounded by a lack of civil-sector consultation during this protracted period of change. Mechanisms for addressing sustainability and incorporating environmental issues within local government planning and decision-making are absent from national legislation. Local government sustainability planning represents such a mechanism. This study researches the current status and future prospects for local government sustainability planning using the Cape Metropolitan Area (CMA) in South Africa as a case study. A framework for local government sustainability planning is developed based on the current national and local contexts. The proposed framework places the fundamental principles of sustainability at the highest strategic level in the authority. Alongside these principles are key operational themes of sustainability. Each of these should be used to guide and inform decisions and activities carried out within the local government authority. As we enter the new millennium local government in South Africa has an increasing responsibility to achieve local sustainability and in so doing to elevate its citizens quality of life. A bold response to local sustainability planning is required if this is to be achieved.

Includes bibliographical references (leaves 87-91). / The work presented in this dissertation stems from the link that exists between meteorological conditions and the significant accumulation of air pollutants in large urban agglomerations. The research focuses on the Greater Cape Town Area (GCTA), where temperature inversions lead to high air pollutant concentrations and episodes of air pollution. As local meteorological conditions are often manifestations of larger weather producing phenomena (e.g. anticyclones), the work presented studies the changes that may occur in the synoptic conditions associated with temperature inversions, which will consequently affect the rate of occurrence of air pollution episodes. After a brief introduction of the topic, background information on the relevant legislation and the actions taken towards an air pollution abatement strategy and a detailed literature review, the high levels of air pollution in the GCT A during winter and especially during the morning peak hour traffic and their link to temperature inversions are studied in detail for the year 2002. The large scale circulation and its link to temperature inversions are studied through the application of the Self-Organizing Maps technique using NCEP-DOE Reanalysis 2 data and making use of the findings for the year 2002. The synoptic states most associated with temperature inversions are found to be the anticyclonic conditions caused by the South Atlantic High Pressure (SAHP) system and the west coast trough associated with berg winds bringing dry continental air towards the GCT A. The 2002 data also show that more air pollution episode days are associated with west coast troughs than with the SAHP system and the average strength of the temperature inversions associated with west coast troughs is found to be approximately 50 % higher than that associated with the SAHP system. The Global Circulation Models (GCMs) ECHAM5, CNRM-CM3 and CSIRO-MK3.5 are used to study the potential changes in the future climate of the area under the IPCC A2 emissions scenario. ECHAM5 shows a small increase in the synoptic states associated with anticyclonic influence over the south western part of South Africa and CNRM-CM3 shows a small increase in both the synoptic states associated with anticyclonic influence and those associated with a west coast trough. Both models show a small decrease in the synoptic states associated with cold fronts. CSIRO-MK3.5 was not found to adequately reflect the current climatology in the domain, making it difficult to distinguish between model bias and future climate trends.

Includes bibliographic references (leaves 178-197). / Tourism is one of the mainstays of the Mozambican economy but has potentially negative impacts on local communities. This study assessed the extent to which coastal communities in Mozambique are benefiting, or losing, from various tourism initiatives. Data was collected using qualitative and quantitative methods in three case study sites: two cases in Inhambane province (Tofo and Barra) and one in Maputo province (Gala), all representing marginalized coastal communities engaged in tourism.

Integrated Water Resource Management (IWRM) is acclaimed as an important paradigm in the sustainable management of water resources. While the logic of IWRM is largely undisputed, it is often criticised for lacking sufficient guidance on its practical implementation. The gap between theory and practice in IWRM is mainly attributed to divergent interpretations of integration and how implementation should be practically pursued in water governance regimes. This research contributes to the on-going discussion around IWRM by investigating an integrated management initiative in the Berg River Catchment, in the Western Cape, South Africa. The Berg River Partnership (BRP) is a collective of government and non-government actors and stakeholders working together in an effort to improve the Berg River. The Berg River is a socially and economically important water system within the region, supporting a number of crucial industries. The Berg River is also under serious environmental stress due to polluted urban runoff, wastewater effluent discharges, agricultural runoff and the presence of alien invasive flora. The Management and Transition Framework (MTF) is adopted in this study as the framework that underpins the structured analysis of the Berg River Partnership, allowing the principles of IWRM to be identified and assessed in the governance structures and processes of the BRP. The study demonstrates how some principles of IWRM are practically implemented within the Berg River Partnership, while confirming some of the limitations of implementing IWRM.

Fog is a key source of moisture to the diverse coastal Namib Desert biota, delivering five times more moisture than rain. Apart from the importance of fog as a source of water for plants, it is also associated with particulates that may contain essential nutrients for plants. Furthermore, dry deposition can be an important input of nutrients to many ecosystems, but without water, dust deposited on leaves or on soil is inaccessible for plant uptake. In other studies of coastal ecosystems (e.g. Strandveld), it has been found that this combined deposition of nutrients represents a major source of nutrients to terrestrial ecosystems. In the case of the Namib Desert, the range of Arthraerua leubnitziae is limited to those areas where fog occurs. This study was carried out at five meteorological stations in the gravel plains of the Namib Desert, along an east-west transect increasing in elevation inland. I hypothesised that marine-derived deposition contributes to moisture and nutrient supply of Arthraerua leubnitziae, an endemic shrub restricted to the fog zone of the central Namib Desert, and consequently determines its distribution. To test this hypothesis, two sub-hypotheses were developed and tested independently. The first sub-hypothesis was that fog contributed to the distribution range of A. leubnitziae in the central Namib Desert and the second was that fog deposition has a significant potential to supply moisture and nutrients to A. leubnitziae in the central Namib Desert. To test the first sub-hypothesis, I measured fog and rain volume, and plant morphological characteristics at the five sites. In addition, a fog map was derived using climatic variables from the five sites and used with climate and edaphic variables in MaxEnt model of the probability of occurrence of A. leubnitziae. The occurrence of A. leubnitziae was found to coincide with areas with high fog occurrence with fog contributing 36% to the modelled distribution of A. leubnitziae alongside precipitation, elevation and isothermality. In order to test the second sub-hypothesis, I measured nutrients deposited in fog water derived from wet and dry deposition (Ca, K, Mg, Na, Cl, Br, NO₃, PO₄ and SO₄) and plant essential nutrients in plant and soil samples (N, P, K, Ca, Mg, Mn, Fe, Cu and Zn). I also determined the nutrient uptake by stems of A. leubnitziae. During the period of Sep 2015 to Aug 2016, fog provided 92% of the yearly water input across the study sites. Over the course of the sampling cycle, the total annual nutrient content of fog and dust was dominated by Ca and Na. Most of the nutrients (K, Mg, Na, and S) were of marine origin. However, Ca enrichment factors (relative to seawater) were higher than 1, suggesting an input from dust. A. leubnitziae was found to be able to directly intercept and absorb some of the nutrients in the dust and fog via their stems. Even though plant and soil nutrients did not match each other, a contribution to plant nutrition from dust and fog was evident. The low nutrient concentrations in the soils of the Namib Desert and significant inputs from dust and fog suggests deposition is an important source of nutrients for A. leubnitziae. Although work is still required to better understand the importance of fog water uptake for nutrient provision, I have identified that water, nutrients and environmental stress alleviation should not be considered separately in studying the role of fog as a determinant of plant distributions.