Climate change is altering hydrological processes with varying degrees in various regions of the world. This research work investigates the possible impacts of climate change on water resource and Hydropower production potential in central and southern Africa. The Congo, Zambezi and Kwanza, Shire, Kafue and Kabompo basins that lie in central and southern Africa are used as case studies. The review of climate change impact studies shows that there are few studies on impacts of climate change on hydropower production. Most of these studies were carried out in Europe and north America and very few in Asia, south America and Africa. The few studies indicate that southern Africa would experience reduction in precipitation and runoff, consequently reductions in hydropower production. There are no standard methods of assessing the resulting impacts. Two approaches were used to assess the impacts of climate change on water resources and hydropower. One approach is lumping changes on country or regional level and use the mean climate changes on mean annual flows as the basis for regional changes in hydropower production. This is done to get an overall picture of the changes on global and regional level. The second approach is a detailed assessment process in which downscaling, hydrological modelling and hydropower simulations are carried out. The possible future climate scenarios for the region of central and southern Africa depicted that some areas where precipitation are likely to have increases while other, precipitation will reduce. The region northern Zambia and southern Congo showed increases while the northern Congo basin showed reductions. Further south in southern African region, there is a tendency of decreases in precipitation. To the west, in Angola, inland showed increases while towards the coast highlighted some decreases in precipitation. On a global scale, hydropower is likely to experience slight changes (0.08%) due to climate change by 2050. Africa is projected for a slight decrease (0.05%), Asia with an increase of 0.27%, Europe a reduction up to 0.16% while America is projected to have an increase of 0.05%. In the eastern African region, it was shown that hydropower production is likely to increase by 0.59%, the central with 0.22% and the western with a 0.03%. The southern, and northern African regions were projected to have reductions of 0.83% and 0.48% respectively. The basins with increases in flow projections have a slight increase on hydropower production but not proportional to the increase in precipitation. The basins with decreases had even high change as the reduction was further increased by evaporation losses. The hydropower production potential of most of southern African basins is likely to decrease in the future due to the impact of climate change while the central African region shows an increasing trend. The hydropower system in these regions will be affected consequently. The hydropower production changes will vary from basin to basin in these regions. The Zambezi, Kafue and Shire river basins have negative changes while the Congo, Kwanza and Kabompo river basins have positive changes. The hydropower production potential in the Zambezi basin decreases by 9 - 34%. The hydropower production potential in the Kafue basin decreases by 8 - 34% and the Shire basin decreases by 7 - 14 %. The southern region will become drier with shorter rainy seasons. The central region will become wetter with increased runoff. The hydropower production potential in the Congo basin reduces slightly and then increases by 4% by the end of the century. The hydropower production potential in the Kwanza basin decreases by 3% and then increases by 10% towards the end of the century and the Kabompo basin production increases by 6 - 18%. It can be concluded that in the central African region hydropower production will, in general, increase while the southern African region, hydropower production will decrease. In summary, the analysis has shown that the southern African region is expected to experience decreases in rainfall and increases in temperature. This will result in reduced runoff. However the northern part of southern Africa is expected to remain relatively the same with slight increase, moving northwards towards the central African region where mainly increases have been registered. The southern African region is likely to experience reductions up to 5 - 20% while the central African region is likely to experience an increase in runoff in the range of 1 - 5%. Lack of data was observed as a critical limiting factor in modelling in the central and southern Africa region. The designs, plans and operations based on poor hydrological data severely compromise performance and decrease efficiency of systems. Climate change is expected to change these risks. The normal extrapolations of historical data will be less reliable as the past will become an increasingly poor predictor of the future. Better (observed) data is recommended in future assessments and if not better tools and methods for data collection/ should be used. Future designs, plans and operations should include and aspect of climate change, if the region is to benefit from the climate change impacts.

Text in Afrikaans, abstract in Afrikaans and English / Lineere plantegroeipatrone bestaande uit afwisselende grasryke mikrotrog- en boomryke- kruinbane wat parallel met die helling georienteer is, kom voor op die voetbang van die Baviaansberg, in die Warmbadgebied, Noordelike Provinsie. Die hoofdoelwitte van die studie was om uit 'n landskapekologiese benadering die verskynsel te probeer verklaar, om die vertikale en horisontale variasie van eienskappe te kwantifiseer en om die impak van die mens daarop te benadruk. Die differensiasie in die Tukulu- en Etoshagrondvorms in onderskeidelik mikrotroe en -kruine is die gevolg van grondprosesse soos illuviasie van klei, loging en ferrolise.Granulometriese analise dui daarop dat die moedermateriaal van gronde van een bron afkomstig is. Kolluviasie en afsetting van moedermateriaal op die voethang was waarskynlik die beginpunt van landskapontwikkeling waar verdeelde oppervlakvloei van water oenskynlik die mikrostrukture geinisieer het. Na aanleiding hiervan het die ontwikkeling van grondverskille en waterregimeverskille tot plantegroeiverskille gelei. Faktore wat die patroon geaksentueer het is termietaktiwiteite, brand en beweiding. / A linear vegetation pattern consists of alternating grassland micro troughs and woody micro crests lanes which were orientated parallel to the slope occurred on the foot slope of the Baviaansberg, in the Warmbaths area, Northern Province. From a landscape ecological approach the principal aims of the study was to explain the phenomenon, to quantify the vertical and horizontal variation of features and to accent the impact of man on it. The differentiation in Tukulu and Etosha forms in micro troughs and micro crests respectively were the effect of several soil processes. Granulometric analyses showed that the parent material of soil was derived from one source. Colluviation and deposit of parent material was probably the starting-point of landscape development where the divided surface flow of water apparently initiated the micro structures. As a result of this the development of soil and water regime differences lead to vegetation differences. / Geography / M. Sc. (Geografie)

Climate change poses a major environmental challenge, due to its adverse effects on human settlement patterns and food security. The global phenomenon upsets seasonal shifts, leading to changes in planting dates and weather patterns. This unpredictability has severe and adverse effects on farmers and rural communities, as variable environmental factors govern activities related to daily sustenance and food availability. The kind of rapid and intense climate change that South African rural spaces are experiencing now, increase the likelihood of extreme weather events such as droughts, heat waves and floods. There are growing concerns that the rural poor will be unable to adapt. Rural livelihoods are therefore facing overwhelming and extensive environmental threats, while rural dwellers are finding it difficult to adapt and cope. As a result, climate change can thus be described as one of the most complex and dangerous environmental problems challenging rural livelihoods today. The aim of this study was to explore the impact of climate change on rural poverty at Binfield village in the Eastern Cape and to identify the livelihood activities practiced. Furthermore, the research was conducted to ascertain how rural livelihood activities are affected by climate change and identify and assess the effectiveness of adaption strategies employed by the households. The research also aimed to explore and establish further adaptation strategies. This study made use of a qualitative research method. Babooa (2008) argues that qualitative research is concerned with stories and accounts including subjective understandings, feelings, opinions and beliefs. The study used both primary and secondary data for data. The researcher adopted interviews and field observation for primary data whilst secondary data was sourced from journals, articles and internet sources. O‘ Leary (2004) describes the interview as a method of collecting data where the interviewer asks the Interviewee open-ended questions. The questions were based on the key areas of interest. Qualitative research methods are aimed at understanding the rich, complex characteristic nature of human phenomena. Qualitative methods are concerned with understanding human behaviour from the participant‘s own frame of reference.

Desertification is the diminution or destruction of the biological potential of land, and can lead ultimately to desert-like conditions. The vegetation of southern Africa is claimed to have altered over the past 100 years and much of the change is attributed to pastoral practice. In recent years however there has been much debate around the issue of the deterioration and loss of productivity of the natural rangelands, specifically those under communal management. It is one thing to claim that the vegetation has changed but quite another to produce data and analyses to show this unequivocally. Furthermore it is generally difficult to determine the nature and extent of change in natural ecosystems, as one does not know what the optimal base-line conditions should be. For this reason emphasis has been placed on developing models of potential or expected vegetation. By comparing a model of potential or expected vegetation with that of the contemporary vegetation, areas that deviate from expectation can be identified, in so doing providing evidence of the direction of change in the rangelands under various management treatments. The objective of this study was to determine shifts in the vegetation under different land-use treatments, by developing a technique to predict the potential vegetation of an area. In order to explore the nature and extent of degradation at the landscape scale a study site was selected where a range of land-use and rangeland management practices could be studied in parallel. The mid-Fish River valley consists of three markedly different units of land management, namely commercial rangelands, communal rangelands and nature conservation areas. The vegetation within the mid-Fish River valley falls within the Thicket biome and consists of three main vegetation types namely, Short Succulent Thicket, Medium Succulent Thicket and Mesic Bushclump Savanna. The creation of this potential vegetation model was dependent on the direct gradient analysis approach of relating the community patterns with environmental variables. To achieve this, floristic information was collected at sites along a topographical-moisture gradient. A Canonical Correspondence Analysis (CCA) between the environmental variables and the plant communities produced a classification from which the conditions normally associated with the major plant communities were predicted. When projected as a digital map, the qualifying sites provided a testable hypothesis of the potential vegetation. The results of this study showed a definite grazing gradient, which reflects a change from a more mesic environment towards a more arid environment with an increase in utilisation pressure. The predictive vegetation model proved to be useful for predicting the occurrence of the valley thicket communities within the Eastern Cape.

From Summary: This is a geographical study of land use in the Eastern Cape Province. The land use pattern, although related closely to the features of the natural environment, is perhaps even more closely related to the spatial variations of the man-made environment, particularly to the disposition of the different racial groups with their different cultures and economies, and to the kaleidoscopic character of the settlement pattern.

Vegetation stress as a form of degradation is a widespread problem in many catchments in the Eastern Cape province. The Keiskamma is one of the catchments where considerable parts of the thicket biome are stressed. This necessitates an assessment of the status of the thicket biome by way of detecting vegetation stress in the area. The underpinnings of vegetation stress are investigated in this study. As a basic method to evaluate the thicket condition, remotely sensed data were acquired. High resolution ASTER imagery for the Keiskamma area at two different dates (2001 and 2005) was used to compute SVI and NDVI as indicators of vegetation stress conditions. A Digital Elevation Model (DEM) was used to derive slope angle and aspect. By way of digitizing from ortho-photo maps, various land-use types were mapped using Arc View GIS. The relationship between land use, terrain, soil erosion and vegetation stress was established. Field based techniques comprising stomatal conductance measurements were used and compared to remotely sensed data. The SVI and NDVI resultant images expressed similarities in areas depicting vegetation stress conditions at both epochs. A strong linear regression between NDVI and stomatal conductance measurements (mmol/m²) serve to confirm that the NDVI is a reliable indicator of vegetation stress condition. Slope angle and aspect were found to have a significant influence on vegetation stress conditions. Similarly variations in soil moisture and soil surface condition have strong implications for vegetation stress. Amongst other land-use types, abandoned lands were found to have the lowest NDVI values implying an association with the worst vegetation stress scenarios. It was concluded that an element of persistent stress conditions exists amongst the thicket vegetation of the Keiskamma catchment. This was mainly due to land use activities in the area.

A dissertation submitted to the Faculty of Science, University of the Witwatersrand, Johannesburg, in fulfilment of requirements for the degree of Master of Science. Johannesburg, May 2016. / Globally, urban areas are the fastest growing land cover with significant numbers of people residing within these urban spaces. The continuous growth and expansion of urban settlements continue to exert unprecedented negative pressure on the natural environment, and green spaces are increasingly disappearing. In most intermediate and secondary cities of developing countries, loss of urban green spaces is partly due to the knowledge gap in urban planning as well as the lack of comprehensive assessment of the challenges and factors contributing to the deteriorations of urban spaces in these cities. In any given urban environment, green spaces of all types are acknowledged for creating valuable economic, social and environmental services. Urban green spaces are fast becoming means to sustainable development due to their extensive multifunctional roles and benefits to different users. This research focusses on critically assessing the relationship that exists between urban greenness and sustainable development in the city of UMhlathuze, KZN, South Africa. It also explores how urban greening is increasingly tied to urban planning and the challenges that urban greening faces in the context of rapidly increasing urbanisation. Results of this study show that there is increasing need to improve green spaces especially for low income groups who cannot afford to travel out of town to experience natural environments. Urban development therefore calls for stakeholders to follow the principles of sustainable development with reference to ecological systems in urban areas, including community green spaces, gardens, biodiversity, native species and urban green infrastructure. If urban greening is properly planned and integrated into urban development and planning policies, it can brings economic, social and environmental benefits to developing world cities. / GR 2016

Thesis (MScAgric)--Stellenbosch University, 1932. / No Abstract Available

The overall objective of the whole study was to assess whether conservation agriculture (CA) systems can work in the Eastern Cape Province (EC). The CA systems were engaged through cover cropping to address land degradation problems by emphasizing high biomass production in order to realize short term benefits such as moisture conservation, weed suppression and soil fertility benefits under rainfed conditions in the central region of the Eastern Cape province. Since rainfall is the most limiting factor to crop production in the EC, a within season rainfall distribution analysis was conducted to expose the quality of the season (onset, end and duration) and hence the feasibility of CA systems to guide agronomic decisions by farmers in EC. To assess season parameters, thirty four years of daily rainfall was collected from the University of Fort Hare Research station and used to conduct the rainy pentad (5 day rainfall totals) analysis and the daily rainfall analysis using INSTAT software programme. Based on the pentad analysis, results showed that Alice does not have a rainy season in 1 out of 2 years (50% probability) but has one in 1 out of 4 years (25% probability level). This criterion proved to be harsher and conservative when compared to the daily rainfall approach which is more precise in measuring trends on season parameters. The daily rainfall analysis indicated a 65% feasibility for the dry land cropping systems in the EC. The pentad analysis however was effective in illustrating seasonality and it showed that the wet season begins on the 1st of November, ending on the 22nd of March lasting for 140 days. Though the season duration appeared too long, the existence of dry spells during critical growth stages adversely affects the quality of the season. The daily rainfall analysis also managed to derive a signal which can guide planting decisions. For planting to be successful, this analysis determined that 20 mm of rain should be received in two consecutive days after the 1st of November. A screening trial for cover crop biomass production and weed suppression was conducted on-station Fort Hare Research Farm (32°46' S and 26° 50' E), and Msobombvu village (MSBV) (32°44' S, and 26° 55' E) over two seasons (2007/08 and 2008/09). Six summer cover crops i.e. cowpea (Vigna unguiculata), dolichos lablab (Dolichos argenteus), sunnhemp (Crotalaria juncea), buckwheat (Fagopyrum sagittatum), forage sorghum (Sorghum bicolor) and sunflower (Helianthus annus) were evaluated for biomass yield, and weed suppression. Decomposition rates, moisture conservation and residual effects of these cover crops on the succeeding main crop were also evaluated under dryland conditions. The screening trial was laid in randomized complete block design replicated three times. Forage sorghum (Sorghum bicolor) and sunflower (Helianthus annus) were identified as high biomass producers and their dry matter yields ranged from 8 -12 t ha-1. These cover crops can be useful in generating high biomass in rainfed cropping systems in the EC. Other cover crops produced 3 - 4 t ha-1 of biomass which fell short of the 6 t ha-1 expected benchmark. However, these biomass yields were important in weed management since all cover crop species showed a similar degree of weed suppression which surpassed the weed fallow treatment. As dead mulches, the cover crops failed to show residual moisture conservation and weed control benefits for the succeeding maize crop mainly because of poor residue persistence, and low harvestable fallow rainfall. Buckwheat (Fagopyrum esculentum), was selected for further investigations in a follow up trial on station in 2008/09 season because of its weed smothering qualities, suitability to short cycle rotations, and possible allelopathic properties. The trial aimed at finding weed and cost effective management options of buckwheat that are none detrimental to the succeeding maize crop. Results showed that cropping systems where buckwheat is followed by a main crop may not work as they are unprofitable with respect to R100 rand invested. Though perceived to have allelopathic properties, buckwheat failed to demonstrate the possibilities of allelopathic action against weeds. Intercropping trial was conducted on-station in 2007/8-2008/09 seasons to try and find better ways of fitting legume cover crops into maize based cropping systems without compromising production of staple cereals on limited landholdings. The trials evaluated three factors in factorial combination, cover crop planting date, intercropping strategy, and cover crop species. The trial was laid as 2 x 2 x 3 factorial arranged in a split-split plot design. The main plot factor was cover crop planting date, cover crops simultaneously planted with maize and cover crop planted two weeks after planting maize (DKC 61-25). The sub-plot factor was intercropping strategy, strip intercropping and betweenrow intercropping. The sub-sub-plot factor was cover crop species, Dolichos lablab (Dolichos argenteus (Highworth), and Cowpea Vigna ungiculata (Agrinawa) plus control plots of sole maize. Results showed that same time planting of leguminous cover crops with maize using the in-between row intercropping patterns can derive appreciable system biomass (maize/cover crop) yields, utilize land efficiently whilst getting favourable maize grain yield. Based on the rainfall analysis, results showed that the probability of success when relay seeding cover crops after two weeks into standing maize is low (15% chances of success). This suggests that relay intercropping strategies would not work due to the unavailability of a good quality season.

Climate is an important factor of agricultural productivity and many rural dwellers in developing countries depend on agriculture and are highly affected by climate change and variability. The world is currently experiencing climatic changes and variability conditions which results in high temperatures, low rainfall patterns, shortage of water and drought persistence. Climate change and variability is affecting weather patterns and shifting seasons which results in serious repercussions on smallholder farmers. Smallholder farmers are extremely vulnerable to climate change and variability because their farming and production systems are climate sensitive and are not rebound to climate stresses. These adverse effects in developing countries arise from different climate change and variability-related causes, notable extreme weather events, food security, increased health risks in agriculture from vector home diseases, and temperature-related morbidity in environments. The study was carried in King Sabata Dalindyebo Municipality in the Eastern Cape Province in South Africa. This study examines farmers’ awareness of climate change and variability and its effects on agricultural productivity in King Sabata Dalindyebo municipality using a Descriptive Statistics, Binary and Ricardian Model fitted to data from a cross-sectional survey of 200 farmers in King Sabata Dalindyebo Municipality. Both primary and secondary data was used. This research study estimates the effects of climate change and variability on King Sabata Dalindyebo agricultural productivity using a continental dimension of Ricardian analysis. Results revealed that local farmers were aware of climate change and variability and perceived changes in average temperatures and rainfall. The changes in average temperatures and rainfall had adverse effects on crop and livestock production. However, farmers’ awareness of climate change is not to an extent that they presume adaptation to climate change as a necessity and crucial. The results show that climate change and variability affects farm income and there is a non-linear relationship existing between climatic variables (temperature and precipitation) and farm income which depicts U-shaped. The study results indicated that climate change and variability affect agricultural productivity and have an effect on agricultural productivity in King Sabata Dalindyebo Municipality. In view of the research findings, several policy proposals are suggested. The study findings suggest that climate change and variability must be taken seriously and monitored. Policy makers and government officials must support farmers with information distribution,education, market access, well trained extension agents, credit and information about mitigation strategies to climate change and variability which includes institutional and technological methods, particularly smallholder farmers.