Includes abstract. / Includes bibliographical references (leaves 205-223). / This thesis examines the interrelationship between “water, climate change and small towns”. The research question is framed in three parts: 1) can climate change be integrated into existing planning frameworks? 2) can small towns build resilient strategies against projected climate change impacts? and, 3) is adaptation to climate change an economic issue? It is evident that very little synergy exists between the different sectors dealing with water access. A holistic view of access and the impact of climate change does not exist in the sustainable development, urban planning and water resources management sectors. It is therefore proposed that the successful delivery of accessible water services lies with the integration of the urban planning, water resources management and climate change adaptation responses. In order to achieve this, a planning framework is introduced.

Includes bibliographical references / Wild plants assist in supporting human livelihoods worldwide, both within traditional systems of medicine, and as economically useful plants. Indigenous to the Fynbos biome in the north-western part of the Western Cape, South Africa is the leguminous shrub, A. linearis (rooibos), which is extensively used as ethnomedicine by local communities, while also commercially grown and exported for the herbal tea market. Being a range-restricted species, climate change poses a threat to wild plants and their dependent communities, as well as the sustainability of the rooibos industry. Climate mediated impacts on rooibos are mostly substantiated by anecdotal evidence from commercial growers and local communities and have traditionally been insufficiently addressed. This study integrates predictive modelling and empirical data to provide important insights into rooibos' plant physiological functioning in the presence of climatic and environmental constraints. The aim is to determine whether there is evidence of climate change over the rooibos distribution area, how these climate anomalies are expected to affect the species distribution and to perform experimental studies by testing plant physiological functioning of A. linearis under changing climate conditions. Analysis of climate parameters important for rooibos production (rainfall frequency and intensity, temperature extremes and wind speed) have shown that plants will experience a shorter period of water availability during winter, and prolonged exposure to summer conditions (high temperatures and water stress) in the coming decades. Under these conditions, climate envelope modelling suggests that wild and cultivated rooibos types are at risk to lose between 49.8% and 88.7% in the extent of the bio-climatically suitable localities, most notably along the western and northern periphery of the rooibos production area by 2070. Plant physiological responses (growth analysis, gas exchange parameters and leaf carbon and nitrogen isotope ratios) to the assessed climate anomalies were measured in experimental studies at glasshouse and field scale. Specific adaptation mechanisms (increasing water use efficiency, developing a higher level of sclerophylly and altering the allocation of plant reserves) which helped seedlings to survive short term drought in the glasshouse were not able to offset more severe conditions in field settings. Finally, a comparison of wild and cultivated tea has shown an apparent adaptive advantage of wild tea to tolerate increased aridity with greater water economy, and more reliance on biological nitrogen fixation for N nutrition, indicating a potentially less severe scenario of range contraction for wild types than initially indicated. This study provides a more robust prediction of rooibos plant responses to climate change factors to enable more effective adaptive planning and conservation management in a changing climate.

Includes bibliographical references / Drought is one of the natural hazards that threaten the economy of many nations, especially in Southern Africa, where many socio-economic activities depend on rain-fed agriculture. This study evaluates the capability of Regional Climate Models (RCMs) in simulating the Southern African droughts. It uses the Standardized Precipitation-Evapotranspiration Index (SPEI, computed using rainfall and temperature data) to identify 3-month droughts over Southern Africa, and compares the observed and simulated drought patterns. The observation data are from the Climate Research Unit (CRU), while the simulation data are from 10 RCMs (ARPEGE, CCLM, HIRHAM, RACMO, REMO, PRECIS, RegCM3, RCA, WRF, and CRCM) that participated in the Regional Climate Downscaling Experiment (CORDEX) project. The study also categorizes drought patterns over Southern Africa, examines the persistence and transition of these patterns, and investigates the roles of atmospheric teleconnections on the drought patterns. The results show that the drought patterns can occur in any season, but they have preference for seasons. Some droughts patterns may persist up to three seasons, while others are transient. Only about 20% of the droughts patterns are induced solely by El Niño Southern Oscillation (ENSO), other drought patterns are caused by complex interactions among the atmospheric teleconnections. The study also reveals that the Southern Africa drought pattern is generally shifting from a wet condition to a dry condition, and that the shifting can only be captured with a drought monitoring index that accounts for temperature influence on drought. Only few CORDEX RCMs simulate the Southern African droughts as observed. In this regard, the ARPEGE model shows the best simulation. The best performance may be because the stretching capability of ARPEGE helps the model to eliminate boundary condition problems, which are present in other RCMs. In ARPEGE simulations, the stretching capability would allow a better interaction between large and small scale features, and may lead to a better representation of the rain producing systems in Southern Africa. The results of the study may be applied to improve monitoring and prediction of regionally-extensive drought over Southern Africa, and to reduce the socio-economic impacts of drought in the region.

>Magister Scientiae - MSc / The need to improve groundwater security remains critical especially in urban areas where demand for groundwater as an alternative source of water supply increases. Declining trends in availability of surface water because of climate change effects further exacerbates problems of water supply shortage to meet the increasing demand for water, hence the need for groundwater sources. The use of hydrogeophysics data and derivative analysis in understanding aquifer dynamics remains limited and poorly understood therefore, the study argues that when hydrogeophysics data and derivative analysis are not used in aquifer characterization, it results in models that are not solution-based and cannot guide groundwater management. The study was aimed at providing improved understanding on characterization of aquifer dynamics for solution-based modelling while addressing the importance of integrating hydrogeophysics data and derivative analysis in amplifying the heterogeneities that exist in aquifer system.

Climate change is causing increases in the frequency, severity, and extent of fires in the boreal forest, which in turn is expected to change historical cycles of permafrost response and recovery to disturbance. A review of recent literature (forming part of this thesis) shows that there are disparities in current knowledge of post-fire permafrost response. First, the majority of studies on permafrost-fire interactions have been conducted in Alaska, leaving regional gaps for the boreal forest across Canada. Second, there are limited direct measurements of certain variables which affect post-fire permafrost dynamics. These include snow depth, burn severity, and soil moisture, as well as ground ice content and quantified subsidence and thermokarst development. Third, the majority of post-fire permafrost studies address near-surface impacts, neglecting permafrost conditions at depth. Finally, there is a lack of long-term information and regional investigations over a broad range of environmental conditions, particularly how permafrost responds across a variety of ground ice contents. This thesis addresses these knowledge gaps through in-situ measurements and analysis of permafrost conditions following fires occurring over the last half century and in particular in 2014 and 2015, along a 650 km latitudinal transect spanning the discontinuous zones, from isolated patches (57.8°N) to extensive discontinuous permafrost (63.1°N), in northwest Canada. A variety of monitoring techniques were used to evaluate permafrost change, including ground and air temperature measurements, direct current electrical resistivity tomography (ERT) surveys, measurements of frost table depth, snow depth, organic layer thickness, burn severity, and ground subsidence. Samples of frozen and unfrozen soil were collected by coring or pit digging, and laboratory analyses conducted to establish soil characteristics. Laboratory experiments were also performed to establish a relationship between resistivity and temperature, and to generate a threshold between frozen and unfrozen soil that could assist in the interpretation of ERT surveys. A total of 68 sites along the Mackenzie Highway in northern Alberta and southern Northwest Territories (NWT) were examined to evaluate permafrost change due to climate warming and forest fire since an initial survey in 1962. The transect extends through the isolated patches and sporadic discontinuous permafrost zones, including 11 sites which burned at various times between 1971 and 2012. Overall, there has been significant permafrost degradation, especially at sites with thin organic layers and coarse-grained soils. This occurred preferentially at the southern end of the transect, where nearly 2°C of climate warming has occurred, such that even undisturbed sites experienced degradation. However, permafrost has persisted at about half of the sites where black spruce (Picea mariana) canopies with organic layers generally >40 cm thick overlie fine-grained sediments. Permafrost even persisted at the majority of burned sites, but greater frost table depths were observed at those which were burned in 2012. A second transect was established to examine permafrost change following the abnormally severe fire year of 2014 (and more limited fires in 2015) that affected sites across a wide range of conditions in the southern NWT. Eleven monitoring sites were established in the sporadic and extensive discontinuous zones between 2015 and 2016, and annual field surveys were conducted through to 2019, including the first repeat ERT surveys conducted following fire. Permafrost change occurred at all sites, including unburned ones, indicating the ongoing impacts of climate change in the region. Snow-depth days, maximum snow depth, and the nival offset were all greater at burned sites. Permafrost change was more pronounced at burned sites, with greater relative decreases in average apparent resistivity and increases in frost table depths and ground temperatures, particularly at sites with low gravimetric moisture content, coarse soil textures, and organic layers <40 cm thick. These changes are pronounced in the near surface (<5 m depth), with deeper permafrost appearing relatively unaffected within the 5-year post-fire time-frame. The field observations indicate that permafrost can still persist following fire at a significant percentage of locations in the discontinuous zone. However, slow degradation is occurring at both burned and unburned sites due to the warming climate, and particularly at dry sites with coarse-grained soils and thin organic layers. Post-fire permafrost change is evident at sites which burned in the last 10 years, but over the long-term, frozen ground appears resilient to fire, with characteristics like active layer thickness returning to pre-fire levels. Similarly, cold permafrost on the taiga shield is resilient to fire, even with thin residual organic layers. At high ice-content sites, however, where ground subsidence and thermokarst develop, water inundation and permafrost thaw can occur, particularly in areas which have been severely burned. This thesis underlines, therefore, the importance of monitoring and modelling a variety of landscape types to establish post-fire permafrost impacts and temperature trajectory, and more specifically the effects of heterogeneity of drainage conditions, substrate, and organic layer thicknesses on the fate of permafrost in the boreal forest.

We live in a constantly changing world, where recent human-induced changes and climate change affect virtually every component of the Earth's surface and systems. Coastal ecosystems are particularly at risk, as one of the most utilised and urbanised of natural systems worldwide, as well as being at risk from sea level rise. This will degrade or even destroy many feeding and breeding sites. Those species colonising new habitats in an attempt to escape rising sea level and climate change related threats, will be competing for space with the growing human population and urbanisation. Although 97 of 346 seabird species (28%) are globally threatened, 57 (17%) have increasing populations, including 17 gulls (Larinae). The Kelp Gull Larus dominicanus is a cosmopolitan species with an increasing population worldwide. Kelp Gulls in southern Africa L. d. vetula are one of 15 seabird species that breed in the region, and one of only five breeding seabirds listed as Least Concern in the region. Three Kelp Gull breeding colonies in Plettenberg Bay, Western Cape, were surveyed to provide an updated count for this area. A combination of direct counts and the trial use of an unmanned aerial vehicle (UAV),were used as methods of counting nests. The direct monitoring of nests allowed for the effect of different microhabitats on the breeding performance of Kelp Gulls to be investigated, which has implications for their ability to adapt to future habitat changes. The importance of anthropogenic food items in the diet of Kelp Gulls breeding in Plettenberg Bay was explored through the use of regurgitated pellets of indigestible matter, and chick regurgitations, and how this is reflected in the time spent in various areas as shown by GPS loggers and point counts in urban areas. Another aspect of the urban adaptation of Kelp Gulls is the incorporation of anthropogenic debris in their nests, which was examined at eight breeding colonies throughout the Western Cape.

Many studies have projected a future warming over Southern Africa without including the influence of on - going vegetation changes in the region. This study investigates how the vegetation changes may alter the projected warming. For the study, two regional climate models (RegCM and WRF) were applied to simulate the present day (1970 - 2005) and the future (2030 - 2065; IPCC RCP 4.5) climate, with and without vegetation change. The study considers two scenarios of vegetation change: the first accounts for the potential impacts of natural bush encroachment and commercial forestation in the eastern part of South Africa, while the second accounts for the expansion of grass cover along the western region of the Grassland Biome in South Africa. The result s of this study agree with that of previous studies in that elevated greenhouse emissions will induce warming over Southern Africa in the future , but further indicate that the ongoing vegetation change s may considerably alter the magnitude of the warming. Forestation may enhance the warming over the forested area and induce cooling elsewhere. It may also produce wet conditions locally and induce dry conditions over other area within the region. In contrast, the expansion of grass cover may reduce the projected warming over the grass covered area and induce warming elsewhere. It may also induce dry conditions locally and produce wet conditions over other areas in the sub-continent. Both vegetation change scenarios ( i.e. forestation and expansion of grass cover ) alter the projected future climate changes through their influence s on local surface albedo ; while forestation decreases the surface albedo, the expansion of grass cover increase s it . However, the changes in rainfall and temperature from the vegetation changes could enhance the frequency drought over some areas and reduce it over other areas with in Southern Africa. This study, therefore, suggests that the vegetation changes may produce unexpected impacts on future climate. It also suggests that before using vegetation changes to mitigate climate change in Southern Africa, the biogeochemical benefits (i.e. carbon sequestration) should be carefully weighed against biogeophysical effects (i.e. changes in albedo).

Due to climate change, fisher households who depend on fishing for their livelihood are faced with a number of challenges that include low productivity. There is now an acknowledgement internationally that fishers cannot depend on hunting fish when all other food producing sectors have adapted. How economic and feasible is it for fishers to consider aquaculture in the face of climate change? This dissertation investigates the economic viability of aquaculture as a climate change adaptation option in rural fisher communities of Zimbabwe. The southern lowveld district of Mwenezi was used as a case study in the economic evaluation of pond culture and cage culture as a climate change adaptation strategy from a baseline position. Data was obtained from secondary sources which include the private sector involved in aquaculture, civil society organisations and the fishers practising aquaculture in both Mwenezi and another district, Kariba. The cost benefit analysis method of economic evaluation was used to assess the economic viability of pond and cage culture forms of aquaculture. The net present value, internal rate of return and benefit cost ratio were used as the decision criteria. Two scenarios were considered depending on the type of funding for the initial investment - scenario one was built on donor funding support while scenario two relied on a bank loan with interest for financing. A sensitivity analysis was also performed to determine the extent to which different factors affect the economic viability of both pond and cage culture. Both pond and cage culture were found to be economically viable as climate change adaptation options in fisher communities of Zimbabwe. Cage culture was found to have a higher net present value under both scenarios when compared to pond culture. However, under scenario two, pond culture was found to have a higher internal rate of return and benefit cost ratio. The inconsistencies were due to the variations in the scale of upfront investments between pond and cage culture where the latter requires a higher initial investment. Key factors that affect the viability of aquaculture as an adaptation strategy in Zimbabwe include the market price of fish, the cost of fish feeds and the price of fingerlings. While these factors are primarily economic, there are other factors which may affect the viability such as the increasing frequency of natural disasters.

'Green' business is claimed by some South African retailers even though they lack well-founded and integrated sustainable, social, and environmental commitments. This is because no standards of greening exist for retail in South Africa. The purpose of this study is to explore, 'What constitutes green retail in the South African supermarket sector?' This required investigation into the sustainability of the companies' green business processes, social component of sustainability, and the existing state of the green retail sector. The five dominant supermarkets were selected to answer a questionnaire based on different environmental variables and principles. Interviewee responses were supplemented with publicly available company reports and these were then critiqued by allocating a level of commitment to sustainability of companies' green business processes, social considerations of sustainability, and establishing the current state of the green retail sector. Results show that within business processes, sustainable procurement is becoming increasingly accounted for through eco-labels and enterprise development programs. Distribution processes assist in verifying green claims and production. Various international and local sustainability programs are used to validate green efforts in the lack of national standards. Best practice frameworks are being utilised in the absence of local green standards and where limited, some are creating their own innovative solutions. Sustainability is a core focus at an executive level to some to ensure full integration of sustainability. Retailers may not necessarily pursue trends, but they have similar pressures that are often variably addressed. Although retailers' attempts to green their operations may not be standardised, the retail industry in South African has almost privatised sustainability and socio-economic development as they have superseded legislation to contribute to society and transform communities. It is an opportunity for retailers to take responsibility for their operations and in doing so create innovative solutions that address South Africa's environmental and social issues, in spite of the lack of green standards and governmental regulation, and in doing so become leadership companies that are accountable to their consumer base.

Meat consumption has been a prominent part of humanity’s dietary culture, particularly in modern, Western developed nations. However, recent research has shown that collectively reducing our consumption of animal products can have major benefits for mitigating our environmental footprint. Despite a consensus among climate scientists on its potential impact, the public does not recognize the effectiveness of this behavioral shift. Recent efforts to address this have created movements and organizations that focus on reduction of meat consumption (e.g. flexitarianism, reducetarianism, Meatless Mondays), rather than elimination of meat consumption (e.g. vegetarianism, veganism) with the intent of creating a more acceptable message, from a less stigmatized group, thereby reaching more people and resulting in greater change. However, the relative impact of these messages has not been compared in previous work. The present research investigates the perceptions of these messages and messengers to assess if there are differences in how people respond to these messages and change their intentions. Study 1 examined interpersonal communication, testing the difference between a message of giving up meat, coming from a vegetarian, and a message of reducing meat consumption, from a reducetarian. Study 2 extended Study 1, replicating the study while adding a third condition to further differentiate the effects of message and messenger using a reduction focused article from a vegetarian. Study 3 extended the previous studies to communication from NGOs with explicit goals as reducetarian or vegetarian. Across all studies, we find that people are more willing to share messages from a reducetarian perspective than a vegetarian one, people agree with that message more, and indicate that they are closer to reducing up meat consumption after reading that article.