Dissertations / Theses on the topic 'Geomorphology - South Africa - Drakensberg'

Hillslopes usually have high heterogeneity in terms of landscape processes. Interactions occur between geology, geomorphological processes, and vegetation distribution on a hillslope. This study was undertaken to assess the processes and interactions of geology, regolith production, geomorphological processes, channel formation and how these are influenced by the vegetation on a portion of Mariepskop. Mariepskop forms part of the Drakensberg Escarpment, but is a separate hillslope within the Mpumalanga Province. A north-eastern portion of the Mariepskop forms the study site, with a drainage line located within the site. Deciduous bush covers most of the study site, and grassland patches occur on the southern parts of the study site. Quartz-feldspar-biotite gneiss dominates most of the area with the cliff and higher parts consisting of feldspar-rich schist. Three site visits were undertaken where bedrock geology, weathering, soil formation, erosion, mass movement processes and the drainage channel were assessed. Maps of these processes as well as slope profiling and plan forms were compiled. According to the results, Mariepskop shows heterogeneous processes both laterally and vertically, with various degrees of interactions taking place. Underlying geology, mass movements on higher altitudes, and soil creep on lower altitudes occur on both the northern and southern parts. Processes mainly occurring on the northern part are rockfall from drainage channel incision, weathering, rill erosion and fluvial erosion within the drainage channel. Main processes on the southern part are mass movement in term form of slumping/debris flow, and erosion, in particular rainsplash and overland flow. Soil is deeper on northern part than on southern part of the study site. Geomorphological processes interact with the vegetation distribution over the study area. Grassland patches on the southern part of the study site are mainly due to slumping/debris flow, rainsplash erosion, convexity of the plan form (therefore no valleys) and oxidic soils occurrence. Similar geomorphological processes will probably influence grassland patches over the rest of Mariepskop.
Dissertation (MSc)--University of Pretoria, 2013.
gm2014
Geography, Geoinformatics and Meteorology
unrestricted

This thesis provides a description of the periglacial environment and features in the vicinity of Tiffindell Ski resort, on the slopes of Ben MacDhui (3001.2m.), the highest point of the East Cape Drakensberg, South Africa. Active and inactive periglacial features were located, mapped and described. Of particular interest were periglaciar slope deposits including gelifluction turf-banked lobes and stone lobes, and cryoturbation features including polygons and thufur. Local environmental factors, such as aspect, moisture, topography, soil texture and depth of freezing, appear to act as important controls on the spatial distribution of the periglacial features. Identification and quantification of periglacial processes in the regolith was investigated using temperature and soil moisture sensors coupled to dataloggers. Research was undertaken over a 16 month period from June 1995 to September 1996 so that comparisons between the winter conditions of 1995 and 1996 could be drawn. The Tiffindell area was observed to be characterised in the winter months by 'diurnal freezethaw days', as well as by 'ice days', 1996 experiencing colder temperatures than 1995. With more than 78% of the days from May to September 1996 being 'ice days', and simultaneously experiencing high soil moisture contents, freezing penetration to a depth of greater than 0.2m was observed to occur in the Tiffindell area, causing frost heave and gelifluction. The summer thaw of ice lenses that developed in the cold winter months caused surface movement downslope of gelifluction lobes of up to 39mm over an 18 month period, although movement declined rapidly with depth and was essentially restricted to the uppermost 130mm of the regolith. Other features such as sorted and non-sorted polygons and thufur were identified and found to be active under the present climatic conditions and depth of frost penetration at Tiffindell. Stone lobes were identified on the south and southeast-facing slopes at Tiffindell, but are apparently inactive under present climatic conditions. Their existence suggests the presence of severe seasonal frost in the past. The implications of the air and ground surface temperatures, and of seasonal frost penetration for the development of Tiffindell Ski resort were considered, and suggestions regarding their economic significance are presented.

Soil erosion is a persistent problem that requires continued control efforts as agricultural land loses productivity and communities dependent on the land become increasingly vulnerable to decreased food security. The negative effects of soil erosion in Khamopele River catchment, in the Mount Fletcher southern Drakensberg region of South Africa, are manifest in extensive gullying and wetland loss. Soil erosion has resulted in siltation in a recently constructed dam and the alteration of aquatic habitats. This research was undertaken to identify the sources of eroded sediment in the small upper catchments of the Mzimvubu River catchment to inform broader catchment management strategies. The scale of erosion was quantified using field surveys of gully extent and form. Environmental magnetic tracing techniques were used to determine the sources of eroded sediment in Khamopele River and upper Tina River catchments. The radionuclide ¹³⁷Cs was used to determine soil loss over a 55 year period in Khamopele River catchment. The Landscape Connectivity framework was used to describe the sediment source, pathway and sink interactions at sample area level. Results indicated that historical and contemporary land management practices such as uncontrolled grazing, grassland burning and furrows promoted soil erosion in the catchment. Soil erosion was most pronounced in the Taung sample area where there was extensive gullying, tunnelling and subsurface erosion. Environmental magnetic tracing results indicated that there were clear differences in source areas. Despite its prevalence in the area, gully erosion was not shown to be a major source of sediment to downstream sinks. Topsoil and hillslope derived sediment were shown to be mobile in the catchment, suggesting that sheet erosion processes were dominant in the catchment. Radionuclide tracing studies showed that at least 20 cm of soil had been eroded from the Khamopele River catchment surface since 1956. This research has shown that it is possible to distinguish source areas of erosion in the catchment by matching catchment mineral magnetic signatures to those in sink areas. This means that rehabilitation projects can use resources efficiently as the areas needing the most attention can be identified.

The research focuses on the contemporary pollen rain-vegetation relationship for vegetation communities within the Natal Drakensberg, a region which is recognized as having the potential for extensive palynological investigations. The objective was to investigate the fundamental assumption underlying palynology, viz: that the pollen rain of a particular region is indicative or representative of the existing vegetation of that region. If the modern pollen rain is indicative of and/or distinctive for a particular vegetation community then the principle of methodological uniformitarianism can be applied, which states that the present day patterns and relationships can provide a factual basis for the reconstruction of the past through the extrapolation of modern analogues backwards in time. A vegetation survey was conducted in thirteen communities identified as pertinent to the research and a two-year modern pollen rain sampling programme was carried out, using both surface soil and pollen trap samples as a means of recording and quantifying the pollen rain. Once the necessary sample preparation and pollen counts had been performed, descriptive and numerical/statistical methods were employed to determine and describe the existing pollen-vegetation relationship. Descriptive analysis of the data sets was carried out with the aid of spectra depicted as rotated bar graphs and representing the relative percentage frequencies of the collected/counted taxa. Annual and seasonal pollen influx values were calculated and presented. Analysis of variance was applied to test various hypotheses related to sampling strategy and pollen influx variation. Statistical methods employed were two-way indicator species analysis (a classification analysis technique), detrended correspondence analysis and principal components analysis (ordination techniques), canonical correlation analysis (for data set association) and multiple discriminant analysis (for determination of vegetation zonal indices). The latter technique allowed for the probability of modern analogues to be assessed which are necessary for accurate interpretation of fossil pollen assemblages if the assumption under investigation is correct. The findings of the study were that the modern pollen rain-vegetation assumption holds true. Recommendations are put forward regarding future contemporary pollen studies with regards to the number of soil and pollen trap samples required, the magnitude of the pollen count and the numerical/statistical techniques most appropriate to clearly interpret the results. The conclusions are that future fossil pollen spectra can be expected to provide a good indication of former regional vegetation patterns for the study region. The study has extended the limited understanding of the contemporary pollen rain-vegetation relationship in South Africa and enables the interpretation of fossil pollen spectra to be carried out with greater confidence. This in turn lends greater credibility to possible Quaternary environmental change models required to help understand present and possible future environmental change.

The Drakensberg rock-jumper (Chaetops aurantius) is a high-altitude passerine endemic to South Africa and Lesotho, living along a highly disrupted portion of the southern Great Escarpment from the Drakensberg highlands in the north-east to the Sneeuberg in the west, above an altitude of 1500 m. Along with the Cape rock-jumper (C. frenatus), this genus provides one of the stronger faunal links between the floristic biomes known as the Drakensberg Alpine Centre (DAC) and the Cape Floristic Region (CFR). Despite this, there is a significant lack of information regarding the species. The great majority of information is based on incidental observation, and no dedicated study has been undertaken. I conducted a series of field excursions between January 2011 and November 2012 in order to explore the rock-jumper’s feeding ecology, diet, habitat usage and genetic diversity. By trapping the birds, I was able to mark them individually with unique colour ring-combinations, and pluck a tail feather for genetic analyses. Observational data reveal that birds living close to their lower altitude threshold (c. 1500 m) are strongly habitat specific, living in boulder fields dominated by grassy vegetation. However, in areas at higher elevations (c. 2000 – 2500 m) this restriction seemed to fall away, possibly as a result of farming practices in those areas – higher grazing pressure results in shorter grass and less foraging effort for the birds. They live in groups ranging from pairs to small family groups of up to twelve individuals and maintain year round territories. Territory defence takes the form of calling and displaying from a prominent rock or boulder and becomes particularly noticeable just prior to, and during, the breeding period. No colour ringed individuals were ever spotted in boulder fields outside from where they had been initially ringed. This, coupled with the behaviour of territory maintenance, suggests a strongly sedentary lifestyle. Genetic inferences are constrained by a small sample size (only 25 birds were caught), but results indicate that some genetic isolation is occurring – a single haplotype was exhibited in birds from across the southern Escarpment, while seven private haplotypes show that any genetic mixing is likely to be historical rather than current. Historical gene flow would most probably have occurred during the last glacial maximum (18 000 years before present), when the cooler, drier conditions which are currently restricted to high peaks would have been much more extensive, thereby decreasing the distance required for effective dispersal. This is in agreement with the observation results, concluding that although there has been movement of birds across the southern Escarpment in the past, it does not appear to be occurring currently. However, this does leave plenty of scope for further work, particularly in the genetic diversity of the species, and in expanding the ecological observations to include the breeding biology.

A prevalence of wildlife poaching with escalations has occurred since 2008, especially regarding rhinoceros poaching. It is essential to protect southern Africa’s heritage by developing/adapting new research methods and techniques that can assist prosecutors to improve their successes in achieving convictions. The aim of the study was to investigate the use of forensic geomorphology in the context of a poached rhino to assist in the prosecution of suspected poachers. This study was conducted at two experimental study sites which mimicked the aspects of the landscape of rhinoceros by utilising the landscape through a variety of physical, chemical and biological techniques. Trace evidence was removed from the suspects that moved through the mimicked landscape in order to verify if any significant similarities could be identified. The study concluded that a linkage could be recognized between the selected landscape and the trace evidence collected from the suspects’ belongings in both experimental studies. The results from the first experimental study site illustrated that a definite linkage could be made between the suspects and the landscape, whereas the second experimental study site suggested that there was a possibility that a linkage could be made.
Dissertation (MSc)--University of Pretoria, 2016.
Geography, Geoinformatics and Meteorology
MSc
Unrestricted

Patterns of invertebrate species richness and body size across elevational gradients have been well-documented in a variety of studies. However, very little is known about the factors that govern these patterns along elevational gradients. A number of studies have have reported a monotonic decrease in species richness with increasing elevation; while others have observed a hump-shaped pattern, where the peak of species richness occurs at an intermediate elevation. For body size, studies have recorded larger size at higher elevations; some smaller and some have recorded no change across elevational gradients. Even though these patterns have been well-documented, the majority of them did not study invertebrates. This is surprising given that invertebrates such as ants are widely regarded as powerful monitoring tools in environmental management because they are abundant, diverse, easy to sample, sensitive to perturbation and they can indicate long-term general ecosystem change. Elevational gradients are isolated fragmented, spatially complex, comprise harsh environmental conditions and often retain comparatively intact habitats. The steep elevational gradients enable species to track climatic changes over short distances. Temperature varies across elevational gradients and variation in rates of growth and development at different temperatures may lead in differences in the mean body size of an insect species along elevational gradients. Body size can also be associated with species range size and geographic patterns of distribution and diversity. Ant diversity and body size patterns were investigated using data collected during March and November 2011 across an elevational gradient at Mariepskop. Pitfall traps were used to sample ants at five elevational sites and environmental variables were also collected at each sampling site. Body size was measured for some of the individuals selected from all ant species collected and simple regressions were used to examine altitudinal body size patterns within and across species. A total of 92 ant species were collected from 30 genera. Ant species density decreased monotonically with increasing elevation and abundance also declined as elevation increased. Altitude, vegetation complexity, height of grass, proportion of bare ground and clay in the soil were the five environmental variables that contributed significantly to the variance explained in the ant assemblages. Body size increased with altitude within species for Plagiolepis sp. 45, Pheidole sp. 1, Monomorium sp. 12 and Tetramorium sp. 3. No body size relationship was established across species when using the across species method whereas the Stevens method indicates a decrease in body size with elevation. A number of factors are responsible for structuring ant assemblages and body size along elevational gradients and it is not easy to establish to what extent each of the factors is responsible for the variation. Factors such as availability of resources, starvation resistance, accelerated maturation and adaptation to local environment are associated with positive relationship between body size and altitude. Related mechanisms such as desiccation resistance, metabolic rate, competition and predation contributing to the observed responses to elevation are discussed.
Dissertation (MSc)--University of Pretoria, 2014.
Department of Agriculture
National Research Foundation (NRF)
Zoology and Entomology
MSc
Unrestricted

The cosmopolitan Asteraceae tribe Gnaphalieae, or paper daisies or everlastings, form a significant component of both the dry and cool temperate floras of southern Africa. Within this tribe exists a small Afrotemperate genus, Macowania, endemic to the grassland biome of South Africa and occurring almost exclusively within the Drakensberg region, apart from two disjunct species in North Africa. The age, relationships and geographic origin of Macowania is investigated in order to provide insight into the factors affecting speciation, especially uplift events, on this small Afrotemperate genus. A well-supported phylogenetic hypothesis based on both nuclear and chloroplast genes suggests that Macowania is sister to a clade corresponding to the Relhania clade s.s., and that these are in turn sister to a clade containing the genera Athrixia and Pentatrichia. Macowania is monophyletic only with the inclusion of the enigmatic monotypic genus Arrowsmithia, resulting in the future synonymy of Macowania with Arrowsmithia. The anomalous species M. pinifolia, previously part of the genus Athrixia, is placed in a polytomy with the Relhania s.s. clade and the remaining species of Macowania and Arrowsmithia. DNA sequence data could not be obtained for several Macowania species, including the taxa from North Africa. The placement of these species within Macowania is confirmed by means of a parsimony analysis of morphological characters against a molecular backbone constraint tree. One species, M. tenuifolia, is well-supported in two different placements within Macowania by chloroplast and nuclear DNA sequence data. The best position of this species is inferred by incongruence decomposition analysis and morphological affinities. Bayesian relaxed clock methods and ancestral area reconstruction using maximum likelihood and squared change parsimony estimate the age and ancestral area of the genus, and determine the timing and route of colonisation of the Drakensberg. Diversification within Macowania is consistent in timing with the uplift events during the Miocene and Pliocene that resulted in significant vertical movement in eastern South Africa, suggesting that colonisation of the high-elevation Drakensberg grassland by Macowania was promoted by uplift. The topographic heterogeneity and increased river action resulting from the uplift may also have promoted evolution into new habitats and potentially mediated the movement of the ancestor of Macowania into the Drakensberg region via riparian habitats.

From Introduction: The study of San rock art has undergone several different phases in approach to the interpretation of art. Two approaches are currently in use. The first emphasises the art as narrative or literal representations of San life and its proponents may be called the "art for art's sake" school. Adherents to the second approach make detailed use of the San ethnography on the belief system of these people and are highly critical of the literalists because they provide no such context. The second approach has rapidly gained ascendancy and replaced the "art for art's sake" school over the last twenty years. The watershed came with the researches of Vinnicombe (1967) in the southern Drakensberg and Maggs (1967) in the Western Cape who both embarked upon programs of research which had quantification and numerical analysis at their core, so that they could present "...some objective observations on a given sample of rock paintings in a particular area..." in order to compare and contrast paintings from geographically different areas. What Vinnicombe's numerical analyses clearly showed was that the eland was the most frequently depicted antelope and that it must have played a fundamental role "...in both the economy and the rellgious beliefs of the painters...", which opened up the search for what those beliefs might be and how they could be related to the rock art itself. In order to understand what the rock art was all about it was recognised that researchers had to meaningfully contextualise the art within the social and religious framework of the artists themselves. Without the provision of such a relevant context, as many different interpretations of the paintings could be made as there were people with imaginations. Such a piecemeal approach provides a meaningless jumble of subjective fancy which tells us something about the interpreters but nothing about the rock art. It is unfortunate that the advent of this explicitly social and anthropological approach marks the end of the amateur as a serious interpreter of San rock art, for the juxtaposition of the ethnography with the rock art requires a proper training in which the intricacies of symbol and metaphor can be recognised.

Research on hillslope surface processes and hillslope stratigraphy has been neglected in southern Africa. The amount of published literature on hillslope stratigraphy in southern Africa is very limited. Hillslope sediments provide a record of past environmental conditions and may be especially useful in calculating the recurrence interval of extreme environmental conditions such as earthquakes and intense rainfall events. The characteristics of hillslope sediments provide information as to their origin, transport and mechanisms of deposition. No published work could be found that had been undertaken on hillslope surface processes or stratigraphy in the eastern Cape coastal region. This study attempted to fill this gap in the geomorphic literature for southern Africa. The surface processes acting on hillslopes at Burchleigh and Spring Grove in the Alexandria district of the eastern Cape were examined in terms of slope morphology, surface sediment characteristics and the internal geometry of the hillslope sedimentary deposits. The late Quaternary hillslope sedimentary deposits at the two study sites are composed of fine grained colluvial sediments intercalated with highly lenticular diamicts. The fine grained colluvial sediments were emplaced by overland flow processes while the diamicts were deposited by debris flows. The sedimentary sequences at both study sites have a basal conglomerate interpreted as a channel lag deposit. Most slope failures preceding debris flow events were probably triggered by intense or extended periods of rainfall associated with cold fronts or cut-of flows. Seismic events may also have triggered slope failure, with or without the hillslope sediments being saturated. The results of this study indicate that a continuum exists between the slopewash dominated processes of the presently summer rainfall regions of Natal to the present winter rainfall regions of the western Cape where mass movement processes are significant. Hillslope deposits, therefore, provide a record of environmental conditions which may greatly facilitate proper management of the landscape.

Evidence for large deep-seated palaeo-mass movements are found within the Drakensberg. However, the distribution and origin of these movements are not fully documented or understood. By studying the distribution and geomorphic characteristics of palaeo-mass movements in the Northern and Central Drakensberg, this study set out to understand the formation of these large deep-seated palaeo-mass movements. The method was divided into three phases; detection, verification and mapping. Thirty-three possible mass movements were located through the use of a criteria-based searching method of satellite imagery, topographic maps and geological maps. The criteria consists of geomorphic features associated with known international and national palaeo-mass movements. Confirmation consisted of infield verification of the features identified in the criteria and thirteen sites were verified. In the third phase, confirmed sites were mapped, a morphological analysis was conducted and a relative age was estimated. Three important facts were confirmed. Due to the distribution of mass movements within the sandstone formations and close relation to dolerite sills, the geological characteristics, such as weaknesses in the sandstone formations, are considered major predisposing factors. The geomorphic characteristics of the mass movements have a large variety in appearance, size, age and types. This indicates that one single trigger event is an unlikely cause to the movements in this area. This study proposes that the main cause for large deep-seated mass movements in the Drakensberg was the Neogene uplift, which caused deeply incised valleys that led to the ideal conditions for the occurrence of these movements.
Dissertation (MSc)--University of Pretoria, 2016.
Geography, Geoinformatics and Meteorology
MSc
Unrestricted

This study arises from a preliminary environmental impact assessment of a proposal by the Natal Parks Board to develop a 200 bed ecotourism facility at Cathedral Peak in the Natal Drakensberg Park. The author of this study was one of a team of five postgraduate students1 from the Department of Environmental and Geographical Science at the University of Cape Town, hereafter referred to as the Masters Group, commissioned to undertake this assessment by the Natal Parks Board (NPB) in January 1995. The preliminary environmental assessment included a scoping exercise to identify all Interested and Affected Parties (I&APs), as well as a socio-economic survey to identify potential positive and negative impacts of the proposed development on neighbouring communities. In addition, this social investigation served to identify opportunities for community involvement in the project, both in the construction and post-construction phases. The complete terms of reference for this preliminary environmental assessment are contained in Attachment 1.

The uKhahlamba-Drakensberg Park (UDP) is a World Heritage Site known for its cultural San heritage and its natural beauty, which is advertised as a world tourist attraction. Tourism is a debatable issue with regards to its negative and/or positive impacts on rock art along with commodification aspects. Negatively, visitation of sites increased natural deterioration of the site, the art and challenges for cultural resource management. While increased awareness of rock art conservation is a positive aspect through tourism and developments, contributes optimistically. San heritage is unique, defining our cultural identity and has the power to encourage national unification. The aim of this project is to assess the complexities of tourism developments and its immediate impacts at different rock art sites in the UDP through an analysis of management and conservation methods. The monitoring of these mentioned methods applied is important as it evaluates the effectiveness of past techniques and provides suggestions for other rock art sites. The current conditions at nine study sites in the UDP were investigated under three main criteria; deterioration of the sites and paintings through natural and human impacts, tourism developments and management. Data collection followed principles such as; site mapping, narrative recording, graphic documentation, and is represented in evaluation tables. Results concluded that common management methods were implemented at sites to provide standard conservation practices, but every site had room for improvement. The results have led to the formulation of recommendations that can be applied at other rock art sites and can contribute to future management and conservation protocols. The study highlights the unique demands made on rock art sites by tourism and concludes with final comments and recommendations.
Dissertation (MA)--University of Pretoria, 2012.
Geography, Geoinformatics and Meteorology
MA
Unrestricted

In South Africa the need to protect and manage the national water resource has led to the development of the Reserve as a basic right under the National Water Act (1998). The Ecological Reserve relates to the quality and quantity of water necessary to protect the sustainable functioning of aquatic ecosystems. The geomorphological contribution to setting the Reserve has focussed on three groups of information requirements: the spatial and temporal availability of habitat, the maintenance of substratum characteristics, and the maintenance of channel form. This thesis focusses on the second and third information requirements. The thesis has attempted to achieve this by adding value to the theoretical and applied understanding of the magnitude and frequency of channel forming discharge for selected southern African rivers. Many of the eastern sea-board rivers are strongly influenced by bed rock in the channel perimeter, and by a highly variable hydrological regime. This has resulted in characteristic channel forms, with an active channel incised into a larger macro-channel being a common feature of eastern seaboard rivers. Within the active channel inset channel benches commonly occur. This alluvial architecture is used to provide clues as to the types of flows necessary to meet the Reserve. Three river basins are considered : the Mkomazi, Mhlathuze and Olifants. The Mkomazi is a relatively un-impacted perennial eastern-sea board river and forms the research component of the study. The Mhlathuze and Olifants rivers are highly regulated systems and form the application component of the study. Utilising synthesised daily hydrological data, bed material data, cross-sectional surveys, hydraulic data and relevant bed material transport equations, channel form was related to dominant discharge and effective discharge in an attempt to identify the magnitude and frequency offlows that can be considered to be ' effective'. Results from the Mkomazi River indicate that no single effective discharge exists, but rather that there is a range of effective discharges in the 5-0.1% range on the 1-day daily flow duration curves that are responsible for the bulk (>80%) of the bed material transport. Only large floods (termed 'reset'discharges) with average return periods of around 20 years generate sufficient stream power and shear stress to mobilise the entire bed. The macro-channel is thus maintained by the large ' reset' flood events, and the active channel is maintained both by the range of effective discharges and the ' reset 'discharges. These are the geomorphologically 'effective' flows. Results from the Mhlathuze River have indicated that the Goedertrouw Dam has had a considerable impact on the downstream channel morphology and bed material transport capacity and consequently the effective and dominant discharges. It has been suggested that the Mhlathuze River is now adjusting its channel geometry in sympathy with the regulated flow environment. Under present-day conditions it has been demonstrated that the total bed material load has been reduced by up to three times, but there has also been a clear change in the way in which the load has been distributed around the duration curve. Under present-day conditions, over 90% of the total bed material load is transported by the top 5% of the flows, whereas under virgin flow conditions 90% of the total bed material load was transported by the top 20% of the flows. For the Olifants River there appears to be no relationship between the estimated bankfull discharge and any hydrological statistic. The effective discharge flow class is in the 5-0.01% range on the 1-day daily flow duration curve. It has also been pointed out that even the highest flows simulated for the Olifants River do not generate sufficient energy to mobilise the entire bed. It is useful to consider the Olifants River as being adapted to a highly variable flow regime. It is erroneous to think of one ' effective' discharge, but rather a range of effective discharges are of significance. It has been argued that strong bed rock control and a highly variable flow regime in many southern African rivers accounts for the channel architecture, and that there is a need to develop an ' indigenous knowledge' in the management of southern African fluvial systems

The Skoenmakers River (located in the semi-arid Karoo region of the Eastern Cape) is being used as a transfer route for water transferred by the Orange-Fish-Sundays River Interbasin Transfer Scheme. The change in the hydrological regime of this once ephemeral stream to a much bigger perennial river led to dramatic changes to both the physical structure and riparian vegetation structure of the river system. These changes differ for each of the three river sections, the upper,middle and lower reaches. Qualitative, descriptive geomorphological data was gathered by means of field observations and this was then compared to the quantitative data collected by means of surveyed cross-sectional profiles at selected sites along the length of both the regulated Skoenmakers River and a nonregulated tributary of equivalent size, the Volkers River. Riparian vegetation data was gathered by means of plot sampling along belt transects at each site. A qualitative assessment of the vegetation conditions was also made at each site and then added to the quantitative data from the plot sampling. At each site the different morphological units were identified along the cross-section and changes in the vegetation and sediment composition were recorded. Aerial photographs were used as additional sources of data and observations made from these were compared to data gathered in the field. The pre-IBT channel in this river section was formed by low frequency flood flows but the hydrological regime has now been converted to base flows much higher than normal flood flows. Severe incision, erosion and degradation of both the channel bed and banks occurred. In the lower reaches, post-IBT base flows are lower than pre-IBT flood flows and, due to the increased catchment area, the impact of the IBT was better ‘absorbed’ by the river system. Aggradation and deposition increased for the regulated river in comparison to the non-regulated river due to more sediment introduced The IBT had the greatest impact in the upper reaches of the regulated river due to more sediment introduced at the top of the system.

Fluvial systems are dynamic systems in which variables in a catchment and river channel affect the morphology of river reaches. South African rivers are increasingly being exposed to stresses from a combination of factors, one of the most prevalent being the impacts of damming rivers which result in varying downstream sediment fluxes and flow regimes. The sediment load combined with flow characteristics for respective river channels provides the physical habitat for aquatic ecosystems. The damming of the Tsitsa River, through the construction of the Ntabelanga Dam, will change the overall downstream geomorphology. This creates an opportunity for research in the preconstruction window. The current condition of the Tsitsa River was monitored by completing a baseline survey of the channel geomorphology with specific reference to the influence of sediment on river habitats and ecosystem health. Five sites were established in variable reaches of the Tsitsa River, with Site 1 located above the proposed Ntabelanga Dam inundation and Sites 2-5 below the proposed dam wall. Each site included a range of features that can be monitored for their response to the dam. Physical variables, water quality and biota were monitored seasonally to note changes in habitat quality. A baseline survey of the present geomorphology and associated instream habitats of the selected reaches was set up by conducting cross-sectional surveys of channel topography, water slope surveys, discharge measurements and visual and quantitative assessments of substrate. Level loggers were installed at each site to collect continuous data on variations in depth and temperature. Monitoring surveys, in terms of fine sediment accumulation, were conducted to characterise dynamic habitat arrangements and macroinvertebrate community composition. A taxa related physical habitat score for the Tsitsa River was created. The relationship between water quality, physical and ecological characteristics of the Tsitsa River will aid further research in the area as well as create a better understanding of the influence of sediment on river habitats and ecosystem health. Monitoring sites can be used to monitor the impact of catchment-wide rehabilitation on river health prior to the dam being built. After dam construction, the top site above the dam inundation can still be used as a point to monitor the impact of catchment rehabilitation on ecosystem health in terms of fine sediment accumulation.

The Baviaanskloof catchment is a semi-arid catchment located in the Cape Fold Mountains of South Africa. Little is known about the functioning of the complicated Baviaanskloof fluvial system and the role alluvial fans in the fluvial landscape. This thesis will contribute to field of geomorphology and, more specifically, to the field of fan morphometry by producing a standalone fan framework outlining methods to investigate the influence of external and internal control variables on alluvial fans. In this thesis, outcomes of the applied framework and case study are used to develop fan restoration guidelines for the Baviaanskloof Valley. The framework incorporates external and internal fan control variables at a valley-wide and local fan scale. External control variables include accommodation space, base-level change, and drainage basin inputs. Internal control variables include fan style, morphometry and fan channels. In order to apply the framework, fan morphometry data was required. This data was collected by creating a spatial plan of fans and basins in the valley. Outcomes of the applied framework include; an understanding of baselevel change on fans, relationships between fan basin characteristics and the fan surface and insight into fan channel processes. Results of the applied framework are investigated further using bivariate (correlation matrix) and multivariate (principle component analysis and regression analysis) analysis techniques. Significant relationships identified are: drainage basin area versus fan area, fan area and fan slope and drainage basin ruggedness and basin size. The primary outcomes of this thesis include an alluvial fan form-process framework, key considerations to be included in alluvial fan restoration projects and fan restoration guidelines. Contributions of this thesis to broader alluvial fan morphology science includes new insights into general fan literature by compiling a form-process alluvial fan classification framework to identify external and internal fan control variables and identify fan form. Additions have been made to Clarke’s (2010) evolutionary stages to describe stages 4 and 5 of fan evolution that has been adapted to describe fan evolution and differentiate between stages of mature fan evolution. This thesis has also contributed to the study of alluvial fans in South Africa, particularly in the Baviaanskloof Valley. The layout of the procedural guidelines and key considerations for an alluvial fan project provides a guide for rapid fan assessment for maximum cost and time benefits for stakeholders.

Mariepskop (direct translation: “Marieps hill”) forms part of the northernmost edge of the Drakensberg Mountain range in the east of South Africa, and is known for its complex topography associated with meso-scale atmospheric circulation, and therefore its numerous climatic zones. As a result the mountain hosts a high degree of biodiversity. The peak of Mariepskop lies at approximately 1900m Above Mean Sea Level (AMSL), which is higher than the surrounding escarpment to the east bordering the Highveld. Its foothills also extend well into the Lowveld at about 700m AMSL. Mariepskop is therefore ideal for studying airflow exchange between the industrialized Highveld and the Lowveld with its diversity of natural resources. It is also ideal for detecting global warming signals on altitudinal gradients extending from the Lowveld to altitudes above the Highveld escarpment. In this study, long-term National Centre for Atmospheric Research / National Centre for Environmental Prediction (NCAR/NCEP) reanalysis wind data at two atmospheric pressure levels (850hPa and 700hPa), as well as reanalysis near-surface temperature data, were obtained for the Mariepskop region for the austral summer (and winter) seasons. The data was used to force a Computational Fluid Dynamics (CFD) model (also known as STAR-CCM+) across its lateral boundaries with the dominant synoptic flow in order to generate mesoscale simulation output over the complex terrain of Mariepskop. Wind speed and direction modelled results were then correlated to observations measured by three weather stations on Mariepskop. Modelled wind flow results for the summer simulation were also validated against aerial photographs in order to infer whether the model could accurately capture areas with high rainfall, which are related to denser vegetation.
Dissertation (MSc)--University of Pretoria, 2013.
gm2014
Geography, Geoinformatics and Meteorology
unrestricted

>Magister Scientiae - MSc
Urbanisation and storm water input in the Kuils River catchment changed the flow of the river from ephemeral to perennial. This led to flooding problems in the Kuilsrivier central business district. The river was channelised in 2000 to increase the carrying capacity of the channel and thus to reduce the flood risk. This study aims to monitor the impacts of channelisation on the geomorphology and ecology of the Kuils River. This was done by selecting representative study sites upstream, within and downstream of the channelised reach. The geomorphological and ecological characteristics of the river were recorded in detail with changes tracked over a year period incorporating channelisation activities and winter floods.

The primary aim of this research was to develop and test a conceptual model of the geomorphological impacts of river regulation, based on a review of relevant international literature. It was motivated by the fact that there is very little local information on the topic, and it was intended that the model might provide a starting point for assessing the impact of impoundments on South African river systems. At present most research in South Africa on the impact of impoundments is undertaken from an ecological perspective. In order to manage our water resources sustainably it is necessary to have a better understanding of our river systems. South Africa is characterised by a variable climatic regime and, in order to supply water to the various user sectors of the nation, dams have to be larger than elsewhere in the world, to trap most of the mean annual runoff and provide a reliable water store (Alexander, 1985). South African dams have been designed to reduce the variability of a naturally variable regime. The impact of flow regulation in dryland rivers has been described as 'ecologically catastrophic at every level.' It is therefore hardly surprising that the impact of these dams on the natural functioning of rivers is substantial. The conceptual model showed that there are many responses to river impoundment, which are varied and complex, both in time and space. Responses or secondary impacts depended on the nature and degree of the primary impact or process alteration, on the sediment and flow regime of the river. High flows were affected in all cases and low flows were affected in most cases. The simplest form of change was Petts' (1979) concept of 'accommodation' of the regulated flow within the existing channel form. More complex responses occUrred where the channel perimeter was unstable, or where tributaries introduced fresh sediment loads. The river could adjust its long profile, cross sectional area and substrate composition by aggradation or degradation. The conceptual model was used in the Building Block Methodology to predict impoundment impacts at Instream Flow Requirement workshops on the Berg, Komati and Bivane rivers. It was also used in assessing the impact of the Sandile Dam on the Keiskamma river. Tributary junctions were identified as likely sites of change, and the morphology of bars at these junctions was investigated. Due to the number of variables affecting the sediment and flow regime in the system, and due to the fact that the primary impacts were not substantial, it was not possible to come to any decisive conclusions. It would seem that the dam is well located in the catchment, and, because the water is not heavily utilised, the secondary impacts are not great. The conceptual model was found to be a useful basic tool which might contribute to a better understanding of our river systems, and ultimately to improved sustainable resource management.

This study arises out of a proposal of the Natal Parks Board (NPB) to develop a 200 bed hutted camp at Cathedral Peak in the Natal Drakensberg. In line with the NPB's stated commitment to the principles of Integrated Environmental Management (IEM), a multidisciplinary group, comprising five students from the Masters programme of the Department of Environmental and Geographical Sciences of the University of Cape Town, was commissioned to conduct a Preliminary Environmental Impact Assessment (PEIA) on the proposed development. The author was one of the members of this study team, hereafter referred to as the Masters Group, which conducted the PEIA at Cathedral Peak under the supervision of the Environmental Evaluation Unit of the University of Cape Town.

The objective of this review is to summarise the characteristics, significance and evolution of heavy minerals and their accumulations, and to identify the key controls on the development and distribution of heavy mineral concentrations in alluvial systems. These controls can be broadly classified as tectonic setting, geomorphic setting and grain-scale concentrating processes, each of which is discussed. Based on this review, exploration models are developed which are designed to indicate favourable localities for the accumulation of heavy minerals, and trends likely to be exhibited within these accumulations. The models are structured from the broadest scale of target selection, down to the local scale of sample site selection. The major conclusion of this work is that an understanding of process geomorphology is required to develop genetic models of placer development, including a detailed evaluation of climatic fluctuations throughout the Caenozoic. Palaeoplacers such as the Witwatersrand goldfield, are inferred to have formed under similar circumstances of tectonic setting as genetically comparable Caenozoic placers such as those of Otago, New Zealand. The means of preservation of such major basins is however poorly understood.

The Goukou Wetland is a 700 ha unchannelled valley bottom wetland near the town of Riversdale in the Western Cape of South Africa. The wetland is approximately 16 km long and between 200 and 800 m wide, with peat deposits up to 8 m deep that get progressively shallower downstream. The Goukou Wetland is one of the last remaining intact peatlands of significant size in the Western Cape. However, there is increasing human pressure on these peat wetlands, where the dominant plant is palmiet (Prionium serratum), which is endemic to the Western and Eastern Cape Provinces of South Africa. Palmiet is viewed as a problem plant by farmers as it is believed to block waterways and promote inundation of arable land and infrastructure. Many landowners therefore actively remove palmiet from peatlands, threatening the integrity of these wetlands. Although the hydrogeomorphic origin of large, non-peat floodplain and valley bottom wetlands has been investigated in South Africa, unchannelled valley-bottom wetlands with deep peat accumulations are rare features and have not been well studied. The hydrogeomorphic factors leading to peat accumulation have been documented elsewhere in Southern Africa, where aggradation due to sedimentation along trunk streams may block a tributary stream, elevating the local base level of the tributary, creating the accommodation space for organic sedimentation. Alternatively, sedimentation along a trunk stream at the toe of a tributary stream may similarly block a trunk stream, promoting organic sedimentation along the trunk stream upstream of the tributary. This pattern of peat accumulation is associated with declining peat thickness upstream of the blocked valley. In the case of the Goukou Wetland, however, peat depth and organic content was found to increase consistently upstream from the toe to the head of the wetland. The Goukou Wetland was graded along its length, with gradient increasing consistently upstream in response to longitudinal variation in discharge. There was no clear relationship between peat formation and tributary streams blocking the wetland. Instead, the distribution of peat and the extent of the wetland appeared to be controlled by the plant palmiet, whose clonal nature and robust root, rhizome and stem system allowed it to grow from channel banks and islands into fast-flowing river channels, slowing river flows and ultimately blocking the channel. The promotion of diffuse flows within the dense, monospecific stands of palmiet creates conditions conducive to water retention and peat accumulation. By growing across the full width of the valley floor, the plant is able to constrict the stream, trapping sediment and slowing flows such that the fluvial environment is changed from a fast flowing stream to one with slow, diffuse flow. These processes appear to lead to the formation of organic sediment, accumulating to form a deep peat basin. The sustained input of water from the folded and fractured quartzite lithologies of the Cape Supergroup that make up the Langeberg Mountains, which provide the bulk of the water supply to the wetland, is also important in promoting permanent flooding in the wetland. A feature that characterized the wetland was the fact that bedrock across the valley beneath the peat deposits exhibited a remarkably uniform elevation. This suggests that over long periods of time (tens to hundreds of thousands of years), bedrock has been laterally planed across the valley floor. It is proposed that valley widening associated with lateral planning of Uitenhage Formation rocks has taken place during periods of episodic very high flows. During these episodes, erosion cuts into the peat wetland and valley sides, cutting to bedrock and planing the valley floor to a uniform elevation for a given distance from the head of the wetland. Periods of episodic degradation are followed by periods of renewed peat accumulation associated with palmiet establishment, such that the wetland valley is shaped by repeated cycles of cutting and filling. Palmiet can be considered an “ecosystem engineer” that is integral to the formation of these deep peat basins. Removal of palmiet from these systems is likely to have negative consequences for the wetland and its functions in that water storage will be reduced, erosion will increase dramatically, and the water-purification function of the wetlands will be lost. Management of these wetlands, which are close to the geomorphic threshold slopes for their size, is therefore essential if they are to be preserved for the benefit of human well-being.

The Kouga Riparian Rehabilitation Project (KRRP) is seen as a pilot rehabilitation project in the Kouga region that is heavily invaded with Acacia mearnsii along the riparian zones of many mountain streams. Clearing of these black wattles and re-planting of indigenous vegetation are imperative to rehabilitation efforts. In this context, two invaded catchments were identified - the Baviaans and the Heuningnes. The aim of this research is to characterise the effects that the woody alien invasive Acacia mearnsii has had on the river channel morphology of the Baviaans and Heuningnes Rivers. A desktop and initial field analysis of the relevant study area catchments was completed. This was followed by a comparison of the channel morphology of the various study channel reaches using fixed channel transects. Ecological resource quality objectives (RQOs) for river rehabilitation from a fluvial geomorphological viewpoint were then established. A long-term monitoring protocol to assess whether or not these RQOs will be achieved was recommended. Follow-up channel transects were measured post wattle clearance in the Baviaans and short-term (<2yrs) changes in channel form were described. Differences in terms of the effect of Acacia mearnsii on channel form were then interpreted by direct comparison and through statistical analysis. Results indicate a number of significant differences between those channels impacted by black wattle infestation and those channels seen as unimpacted and natural. Short-term changes (<2yrs) that occurred within the study period post Baviaans wattle clearance were shown to be minimal for channel form as well as for bed material. The lack of any clear relationship or explanation between channel form and other channel controls suggests vegetation as the primary control. Vegetation, specifically the invasive alien vegetation, is the key controlling variable acting on channel form in the two study catchments.

Thesis (PhD)--Stellenbosch University, 2012.
ENGLISH ABSTRACT: Worldwide, invasive alien plants (IAPs) alter aspects of invaded ecosystems including geomorphology, above-ground vegetation, soil seed banks and soil nutrient regimes, thereby affecting the long-term stability of ecosystems. In many cases these invasions call for various management interventions, including restoration. Effects of alien plant invaders on native ecosystems are widely acknowledged, but compared to terrestrial ecosystems, riparian habitats are poorly studied. Riparian habitats are inherently rich in biodiversity, but are particularly prone to invasion by IAPs because of their dynamic nature and because these ecosystems are affected by many anthropogenic activities. This enhances the proliferation of IAPs, especially trees such as Tamarix spp. (e.g. in the southwestern United States), Salix spp. (e.g. in Australia), and Australian Acacia spp. and Eucalyptus camaldulensis (in South Africa). Initiatives such as the Working for Water (WfW) programme in South Africa that are focusing on clearing IAPs, particularly in riparian zones, have reported much success in the short term, but ecosystem recovery remains limited. There is a poor understanding of the nature of the impacts of invasive trees, and of the opportunities that exist for ecosystem restoration. The objective of my thesis was to investigate the effects of the widespread invasions of Eucalyptus camaldulensis in riparian zones. Methodological constraints have been identified as one reason for limited success of restoration projects. Many studies examining the effects of IAPs used a comparative approach of uninvaded (reference) and invaded sites. However, this approach often fails to separate cause from effect. An experimental removal approach has been suggested as an alternative, but it is often inappropriate for large invasive trees owing to time and cost constraints. I used a comparative gradient approach, involving sampling along a continuum from uninvaded sites, and varying E. camaldulensis invasion densities categorised as “lightly”, “moderately” and “heavily” invaded (hereafter the gradient of invasion), each with four replicates (n = 16). This approach enabled me to detect trends that could be reliably attributed to invasion. Furthermore, my study attempted to provide a comprehensive understanding of the effects of IAPs in invaded ecosystems by considering various components of the ecosystem and integrating their feedback relationships to establish the net effects on ecosystem processes. The riparian zone is a unique ecosystem which provides an opportunity for such a multifaceted study examining and integrating the effects of invasive trees on riparian geomorphology, above-ground vegetation, soil seed banks, and soil properties. I studied the effects of E. camaldulensis invasion in riparian zones along the Berg River in the Mediterranean-type climate zone of the Western Cape, South Africa. I asked the questions 1) Are environmental conditions (i.e. the riparian environment created by geomorphological processes) altered by Eucalyptus invasion and if so, are these conditions less suitable for recruitment of indigenous species? 2. Has Eucalyptus invasion altered the composition of indigenous species (potentially limiting post-clearing propagule supply)? 3: How does Eucalyptus invasion change the composition of the riparian soil seed bank; and its potential to re-initiate ecosystem recovery? 4: Do soil properties (physical and chemical) change with Eucalyptus invasion? Data for all four questions were collected in the same sites to enable cross comparisons. For the first question, I employed photogrammetry techniques in a GIS and remote sensing environment to analyse repeated aerial photographs (1938 -2010) to reconstruct the invasion history and riparian geomorphology evolutionary dynamics. For the second and third questions, I compared richness, diversity, evenness and composition of resident above-ground and seed bank vegetation between uninvaded sites and the gradient of invaded sites. For the fourth question, I compared a set of variables describing physico-chemical properties in uninvaded sites to the gradient of invaded sites seasonally. Results of the geomorphology study showed that the riparian zone has been very dynamic over the 70 years, with a 13.5% net decrease in area. There was evidence of channel narrowing, riverbank steepening and river bed incision in areas that were densely invaded. No significant trends were detected in hydrometeorological data. The above-ground vegetation study revealed that species richness, diversity and structural attributes (e.g. height, relative cover and mean basal diameter) of native species decreased consistently along the invasion gradient. Invasion also altered native and alien plant species composition, both of which showed a high preference for lightly invaded sites. The seed bank study revealed that E. camaldulensis invasion had no significant effect on total and native species richness, diversity and evenness, however the effects were bigger on native than alien species. Alien species density was significantly higher than native species density. Invasion also influenced the composition of the native seed bank. However, native seed banks were more diverse than above-ground plant assemblages with some native fynbos species occurring only in the seed bank. In the soil study, I found that soil pH levels were significantly lower in invaded sites than in uninvaded sites in all seasons. Litter cover and thickness increased significantly with invasion intensity. Soil moisture decreased consistently with invasion intensity while temperature increased in winter and spring. Total macro, micro and available nutrients did not vary significantly along the invasion gradient (p > 0.05), but exchangeable cation content was significantly higher in uninvaded than in invaded sites, especially in winter and spring. Narrowing of river channel and steepening of river banks reduces the suitability of the riparian zone to perform certain ecological functions such as soil seed storage and providing space for vegetation to grow. This reduces opportunities for seedling recruitment and consequently reduces species diversity. Conversely, the reduction of species diversity in above-ground vegetation reduces seed input into the soil leading to depauperate soil-stored seed banks. The abundance of seeds of Acacia mearnsii in the soil-stored seed bank poses a threat of secondary invasions post clearing of E. camaldulensis if this is adopted as a management action. The study was successful in addressing the stated objectives. The transition from a native-dominated riparian plant community to a monoculture of E. camaldulensis over c. 50 years has resulted in marked changes to riparian geomorphology and above-ground vegetation, but has yet to radically change the total soil seed bank and soil nutrient concentrations. The findings offer support to the WfW clearing initiatives and show that potential for recovery of native species after removal of the invasive eucalypts still exists. This knowledge not only enhances effectiveness of restoration and long term management of riparian ecosystems, but also advances the field of riparian ecology and restoration. Further experimental work is needed to establish the mechanisms responsible for the changes associated with Eucalyptus invasion. The contribution of agriculture in shaping channel morphology also needs to be investigated.
AFRIKAANSE OPSOMMING: Die langtermyn stabiliteit van ekosisteme wêreldwyd word bedreig deur uitheemse indringer plante (UIPs) wat, onder andere, die geomorfologie, bo-grondse plantegroei, onder-grondse saadbanke en voedingstofstatus van ekosisteme kan verander. In baie gevalle word bestuursoperasies vir indringer plante vereis, en sluit onder andere herstel (restorasie) in. Die invloed van UIPs op inheemse ekosisteme word wyd erken, maar kennis oor oewerbank-habitatte, in vergeleke met ander terrestriële ekosisteme, skiet steeds tekort. Oewerbank-habitatte is inherent ryk aan biodiversiteit maar uiters sensitief vir indringing deur UIPs. Dit is weens die dinamiese aard van hierdie ekosisteme asook vele menslike aktiwiteite in hierdie tipe habitat. Dit dra by tot die vermeerdering van UIPs, veral bome wat byvoorbeeld insluit Tamarix (tamariske) (bv. in die suid-wes van die Verenigde State van Amerika), Salix (wilger) (in bv. Australië) en die Australiese Acacia (wattel) en Eucalyptus spesies (bloekom) in Suid Afrika. Inisiatiewe soos die Werk vir Water (WvW) program in Suid Afrika fokus juis daarop om UIPs vanuit oewerbank areas te verwyder, en alhoewel groot sukses in die kort termyn behaal is, is die herstel van ekosisteme steeds beperk. Daar is dus min inligting beskikbaar oor die impak van indringer bome en gevolglik ook oor geleenthede vir die herstel van hierdie ekosisteme. My tesis ondersoek die impak van die wydverspreide voorkoms van die indringer, Eucalyptus camaldulensis, in oewerbank-omgewings. Beperkte metodes is tans beskikbaar om die impak van indringer plante te ondersoek, en dit is geïdentifiseer as een van die oorsake vir die beperkte sukses van herstelprojekte. Baie studies ondersoek die effekte van UIPs deur natuurlike areas sonder enige indringer plante te vergelyk met areas waar UIPs voorkom. Hierdie tipe benadering kan ongelukkig, in meeste gevalle, nie onderskei tussen die oorsaak en die impak nie. ʼn Alternatiewe voorstel is om UIPs eksperimenteel te verwyder, maar is ongelukkig nie van toepassing op groot bome nie weens die tyd en kostes verbonde hieraan. Ek het gebruik gemaak van ʼn vergelykende-gradiënt benadering wat steekproefnemings langs ʼn geleidelike kontinuum van natuurlike areas sonder enige indringer plante na areas wat effens gematig, en erg ingedring is (hiernaas bekend as die indringer-gradiënt) deur die indringer, E. camaldulensis. Die steekproefnemings van elke kategorie van indringing (geen, effens, gematig en erg) is vier keer herhaal (n = 16). Hierdie benadering het my toegelaat om neigings te identifiseer wat met sekerheid toegeskryf kan word aan die teenwoordigheid van indringers. My studie het ook verder gemik om ʼn omvattende beskrywing van die impak van UIPs in ekosisteme met indringers te verskaf deur verskeie komponente van die ekosisteem, sowel as hul terugvoer-verhoudinge, in ag te neem, en sodoende die totale effek op ekosisteem prosesse te bepaal. ʼn Oewerbank is ʼn unieke ekosisteem wat ʼn geleentheid bied vir ʼn veelsydige studie wat die impakte van indringer bome op oewerbank-geomorfologie, bo-grond plantegroei, grond saadbanke en grondeienskappe, kan bestudeer en integreer. Ek het die impak van die teenwoordigheid van die indringer, E. camaldulensis in oewerbank areas langs die Bergrivier, wat ʼn Meditereense-tipe klimaat het, in die Wes Kaap, Suid Afrika, bestudeer. My studie het die volgende vrae gevra: 1) Is omgewings-omstandighede (bv. die oewerbank-omgewing geskep deur geomorfologiese prosesse) verander deur die teenwoordigheid van die Eucalyptus indringing, en indien wel, is hierdie omstandighede minder geskik vir inheemse spesies?; 2) Het die indringing van Eucalyptus gelei tot ʼn verandering in die samestelling van inheemse spesie gemeenskappe (moontlik beperkte plant voorplantings materiaal nadat die indringer verwyder is)?; 3) Hoe verander die indringing van Eucalyptus die samestelling van saad teenwoordig in die grond (saad bank) van die oewerbank en het dit die potensiaal om ekosisteem-herstel weer aan die gang te sit?; 4) Verander indringer Eucalyptus grond eienskappe (fisies en chemies)? Data vir al vier vrae is by dieselfde plek versamel om vergelykings te kan tref. Vir die eerste vraag het ek fotogrammetrie-tegnieke in ʼn Geografiese Inligting Stelsel (GIS) en afstandwaarnemings-omgewing toegepas om herhaalde lugfotos (1938-2010) te analiseer om die indringings geskiedenis sowel as die oewerbank se geomorfologiese evolusionêre dinamika saam te stel. Vir die tweede en derde vraag, het ek die aantal, diversiteit, gelykheid en samestelling van die bo-grond en saad bank plantegroei tussen natuurlike (geen indringers) en die gradiënt met indringers vergelyk. Vir die vierde en laaste vraag, het ek ʼn stel veranderlikes wat die fisies-chemiese eienskappe van die natuurlike omgewing sonder indringers beskryf, vergelyk met die eienskappe van die indringers gradiënt op ʼn seisoenale basis. Die resultate van die geomorfologiese studie wys dat die oewerbank omgewing baie dinamies was oor die afgelope 70 jaar met ʼn totale afname van 13.5% in rivieroewer-area in die gebied wat bestudeer is. Daar is ook bewyse vir ʼn vernouing van die kanaal, toename in die steilte van die rivierbank sowel as insnyding in die rivierbedding in areas wat ernstige indringing ervaar. Daar was geen beduidende neigings in die hidro-meteorologiese data nie. Die studie van die bo-grondse plantegroei het gewys dat die aantal plantspesies, diversiteit en strukturele kenmerke (bv. hoogte, dekking en gemiddelde basale diameter) van inheemse spesies afneem soos wat die indringings gradiënt toeneem. Indringing verander ook die inheemse sowel as uitheemse plant spesies samestelling. Beide inheemse en uitheemse spesies het areas wat slegs effense indringing wys, verkies. ʼn Studie van die saad bank (aantal sade in die grond) het gewys dat die indringer, E. camaldulensis geen merkwaardige invloed op die aantal, diversiteit en gelykheid van die totale en inheemse spesies teenwoordig gehad het nie. Die aantal uitheemse spesies was merkwaardig meer as die aantal inheemse spesies. Alhoewel indringing ook die samestelling van die inheemse saadbank beïnvloed het, was die inheemse saad bank, waarvan sommige spesies slegs daar voorgekom het, meer divers as die bo-grond plant samestellings. ʼn Studie van die grond het gewys dat die pH vlakke, afgesien van die seisoen, aansienlik laer is in die areas met indringers in vergeleke met areas sonder die indringers. Die hoeveelheid en dikte van plantmateriaal op die grond neem ook toe met ʼn toename in indringers. Die waterinhoud van die grond het afgeneem met ʼn toename in indringers en temperatuur het verhoog in beide winter en lente. Die totale makro- en mikrovoedingstowwe het nie merkwaardig gewissel saam met die indringingsgradiënt nie (p > 0.05), maar die uitruilbare katioon inhoud was aansienlik hoër, veral in die winter en lente-maande, in die areas sonder indringers in vergelyking met die areas met indringers. Vernouing van rivierkanaal en versteiling van rivieroewers verminder die geskiktheid van die oewersone om sekere ekologiese funksies te verrig soos grond-saadstoring en die verskaffing van ruimte vir plante om te groei. Dit verminder geleenthede vir werwing van saailinge en verminder gevolglik spesiediversiteit. Aan die ander kant, die vermindering van die spesiediversiteit in die bogrondse plantegroei verminder saadinsette in die grond en dit lei tot verarming van grondgestoorde saadbanke. Die oorvloed van sade van Acacia mearnsii in die grondgestoorde saadbank hou die bedreiging van sekondêre indringing in na die skoonmaak van E. camaldulensis indien dit wel as 'n bestuursaksie aangeneem word. Hierdie studie het die uiteengesette doelwitte suksesvol aangespreek. Die oorgang van ʼn oewerbank-gemeenskap wat hoofsaaklik uit inheemse plante bestaan na ʼn gemeenskap wat slegs uit E. camaldulensis bestaan, oor ʼn periode van ongeveer 50 jaar, het duidelike veranderinge tot gevolg gehad. Hierdie veranderinge is veral opmerklik in die oewerbank-geomorfologie en bo-grondse plantegroei, maar tot op hede is dit nog nie so opmerklik in die saadbank en grond-voedingstowwe konsentrasies nie. Hierdie bevindinge bied ondersteuning aan die WvW verwyderings-ondernemings en wys dat daar wel moontlike herstel van inheemse spesies kan wees na die verwydering van die indringer Eucalyptus. Hierdie kennis dra nie net by tot verhoogde effektiwiteit van herstelwerk en langtermyn-bestuursplanne nie, maar ook tot die navorsingsveld van oewerbankekologie en-herstel. Verdere eksperimentele navorsing word benodig om die moontlike meganismes wat verantwoordelik is vir die waargeneemde veranderinge, geassosieerd met Eucalyptus indringing, te verduidelik. Die bydrae van landbou tot die vorming van kanaal morfologie moet ook verder bestudeer word.

A thesis submitted to the Faculty of Science, University of the Witwatersrand, in fulfillment of the requirements for the degree of Doctor of Philosophy Johannesburg, 2012.
A variety of mass movement landforms occur in the southern Drakensberg, South Africa, and whilst a number of studies on individual landforms have been conducted, regional scale assessments of the Ukhahlamba Drakensberg Transfrontier Park have been relatively limited. Mass movement has been defined as the downward and outward movement of slope-forming material under the influence of a transporting agent such as water, air, ice or snow (Goudie, 2004). This includes landforms such as landslides, debris flows, terracettes, solifluction lobes and rockfall. Although two landslide risk assessments have been conducted in the region, one was site specific and focussed on shallow, translational slides (Bijker, 2001), whilst the other was at a much larger regional scale and focused on large palaeo-mass movements (Singh, 2008). Numerous international mass movement classifications have been developed over the years, and one of the primary aims of this research is to develop a classification for mass movement landforms within a southern African context. A number of mass movement landforms were identified, measured and mapped in the field to acquire a better understanding of how the landforms originate. This classification was then further adapted to facilitate the identification of mass movement landforms from orthophotos. Aerial photo interpretation techniques were used to map three terrace-type mass movement landforms and four shear-type mass movement landforms in the Garden Castle State Forest of the Ukhahlamba Drakensberg Transfrontier Park. A further level of detail was added to the classification by ascribing environmental conditions to the different landform types. A Geographic Information System was used to collate and generate spatial information which could be added to the landforms in the mass movement inventory. These were then analysed using univariate and multivariate statistical modelling. Histograms, as well as an area-weighted frequency distribution, were used to describe the landforms and then hierarchical partitioning was used to identify the environmental variables associated with each type of landform. One main environmental variable was identified for each type of mass movement. Logistic regression was then used to create probability maps for each type of landform. An average of 30% of the study area has a medium to very high likelihood of developing mass movements, although this percentage varies for each type, whilst rock movement deposits are predicted to occupy more than 80% of the study area. Gradient, altitude and lithology were selected most frequently by the statistical models as influencing landform distribution, whilst distance to a rock exposure had the strongest influence on the location of rock movement deposits. Aspect was selected least frequently by hierarchical partitioning which raises questions about the influence of aspect on valley asymmetry. Various models have been developed which describe slope development in the Drakensberg with reference to slope aspect, however the results of this study suggest that other environmental factors may be more important and that slope development is a complex process.

A dissertation submitted to the Faculty of Science, University of the Witwatersrand, in fulfilment of the requirements for the degree of Master of Science August 2017.
Streamwater chemistry is influenced by several factors that include: geology, soil-geology interactions, land use, climate change, topography, vegetation, mechanical and chemical weathering. The dominance of these factors when determining the chemistry of streamwater varies from one situation to the other. Four different catchments in the Drakensberg were monitored to identify the processes determining temporal and seasonal patterns in streamwater chemistry. The land uses of the catchment include: CP03 (previously afforested, degraded), CP04 (pristine grasslands), CP06 (pristine grasslands) and CP09 (protection from fire). All the catchments were investigated for differences in major ion concentrations, streamwater temperatures, dissolved organic carbon (DOC), dissolved oxygen, pH, conductivity. There were comparisons made between historical and recent data collected at the Cathedral Peak Research Site. Comparisons were made between CP03 and CP06 to identify effects of storm events on streamwater chemistry. CP03 and CP09 had significant statistical differences in terms of major ions. Land use and stormflow path ways were most influential in determining the streamwater chemistry across catchments.
LG2018

Change in land use has had major impacts on natural resources. Mountain terrains and their associated natural resources are especially vulnerable to extensive changes in land use. We evaluated climate, demographic and socio-economic changes for two study areas in the Drakensberg Mountains, as possible drivers of land use change in each study area. The most notable change in land use within the study areas was the increase in urban areas despite the fact that the study areas are located within areas dominated with primary economic activities. Trends in climate change were not consistent between the various weather stations with the majority of the weather stations experiencing no significant changes in temperature and rainfall. Although there was a relatively slow positive population growth in the two study areas, it was not a main driver of the changes in land use. We found that socio-economic factors, including increased formal employment, income and migration to urban centres were much more important in driving land use change in these rural environments.
Dissertation (MSc)--University of Pretoria, 2016.
tm2016
Zoology and Entomology
MSc
Unrestricted

Certain debris accumulations in Bottelnek are ascribed a rock glacier origin on the basis of morphological and sedimentological evidence. Radiocarbon dating indicates that rock glaciers were active at or subsequent to 21 000 BP and that cold, stadial conditions, existed on the region after 27 000 BP and before 13 000 BP, during the Bottelnek Stadial. At least sporadic permafrost existed in Bottelnek when the rock glaciers were active.

Recent research has emphasized the importance of understanding the consequences of species loss, not just for biodiversity per se, but also for ecosystem resilience and functioning. Firstly, a baseline analysis of the effects of a naturally patchy landscape on avian community composition and resilience in a high altitude Afrotemperate forest landscape in South Africa is presented. Bird data from a point count survey of 706 counts at 31 forest sites was used to test whether taxonomic species diversity, functional species richness and density of birds provide insight into community resilience in this historically patchy ecosystem. Bird species richness of forest patches ranged from 17 to 38, with a total species richness of 50. Density was slightly but negatively related to both area and species richness. That density compensation is occurring in these Afrotemperate forests suggests a level of resilience in this system. Following on from this, cumulative species-area and function-area graphs were derived to quantify the loss of forest area or taxonomic bird species richness that this landscape may potentially sustain before ecosystem functioning is negatively affected. The concept that species’ patterns of distribution, abundance and coexistence are the result of local ecological processes has recently been challenged by evidence that regionalscale processes are equally instrumental in shaping local community composition. The historically and naturally fragmented Afrotemperate forests of the uKhahlamba– Drakensberg Park, South Africa, offer an interesting test case. In this study the relative effects of local and regional-scale processes on species assemblages in a naturally patchy forest system were investigated. By employing species-area and species-isolation relationships, and nested subset analyses, we showed that isolation (regional-scale process) had a greater effect on bird species richness and composition than area (local-scale process), though the species-area relationship was significant. Using generalized linear models and an information-theoretic approach to model selection, patch area, the size of the regional species pool as well as the distance to the nearest Eastern Mistbelt forest were all influential in determining local bird species richness in these montane forests. Thus, localities are regionally enriched within the constraints on species occupancy provided by the available habitat.
Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2009.

Eight climatic events during the Holocene are evidenced in the East Cape Drakensberg by fluvial, archaeological and palynological deposits. Flood plain deposition under relatively moist conditions occurred in the Early Holocene, before ca. 7000 BP. Semi-arid conditions with limited fluvial activity dominated the Mid Holocene until ca. 3200 BP. Alternating flood plain erosion and deposition occurred in the Late Holocene. Four climatic events, for which there is palynological and limited archaeological evidence, have been identified in the Late Glacial.

Eight climatic events during the Holocene are evidenced in the East Cape Drakensberg by fluvial, archaeological and palynological deposits. Flood plain deposition under relatively moist conditions occurred in the Early Holocene, before ca. 7000 BP. Semi-arid conditions with limited fluvial activity dominated the Mid Holocene until ca. 3200 BP. Alternating flood plain erosion and deposition occurred in the Late Holocene. Four climatic events, for which there is palynological and limited archaeological evidence, have been identified in the Late Glacial.

Hlogoma Mountain is a small inselberg surrounded by farms and commercial forestry in the Underberg district (KwaZulu-Natal) within the Gs10 Drakensberg Foothill Moist Grassland. As little is known about the vegetation on Hlogoma, a survey was undertaken to classify, map and describe the plant communities occurring on the inselberg. A total of 100 (16 m2) randomly stratified sample plots were placed in homogeneous vegetation units within the 117 ha study area. A TWINSPAN classification, refined by Braun-Blanquet procedures, resulted in the identification of two major communities, five communities, 12 sub-communities and four variants. All communities were described and a vegetation map constructed. Ordinations identified key environmental variables that have an impact on the vegetation at the study site. A plant species checklist was created and analysed for floristic composition; rarity and threatened species; medicinal plants; endemism; phenology; flower colour and elevation range; species richness and plant community biodiversity. A total of 467 species were identified, represented by 271 genera and 87 families. Four Red Data species and a new Aspidoglossum species were discovered. Two near-endemic genera, two endemic species and 88 near-endemic species belonging to the Drakensberg Alpine Centre were found on Hlogoma. This study showed that Hlogoma Mountain is an inselberg with high plant species richness and endemism, and is a refuge of conservation importance for biodiversity.
Environmental Sciences
M. Sc.(Environmental Science)

M. Tech. Architectural Technology
The aim of this study was to investigate the climate influence of a conservatory added to an existing building. The interior temperature and relative humidity levels were measured, analysed and compared with that of the exterior, to determine in which seasonal cycle the conservatory was more effective as an interior climate enhancement system. The building on which the case study was based is a farmhouse, retrofitted with a conservatory, situated in KwaZulu-Natal, near Bergville in the Drakensberg region. The owner added a conservatory to the existing building, in an attempt to achieve a more temperate indoor climate by harnessing natural energies. The South African climate is typified by varying high diurnal temperatures, with some climatic zones experiencing high summer and/or low winter temperatures. The conservatory was therefore used as a design measure to create a passive solar environment within an enclosed intermediate area.

A thesis submitted to the Faculty of Science, University of the Witwatersrand, in fulfillment of the requirements for the degree of Doctor of Philosophy. Johannesburg, 1998
The appearance of the dry Molopo River with its generally wide and shallow valley cut into the Kalahari Group sediments, but more especially its few impressive rock-cut gorges, has intrigued many people over the ages, and led to many theories concerning its history. The rock-cut gorges, in particular, have traditionally been attributed to ancient, previously much more extended drainage lines, more or less in the same geographical position as the present Molopo Valley. An analysis of the sediment body of the Kalahari Group, and both, alluvial gravels and geomorphic features on the rim of the Cainozoic Kalahari Basin, have indicated that the Molopo drainage has gradually shifted westward over time, in response to a tilting of the drainage area, which lies across the south-eastern rim of the Kalahari Basin, The present geographical position of the Molopo River is thus a relatively recent one in its evolution. The earliest traces of drainage lines in the area predate the Permo-Carboniferous glaciation of Gondwana. A preglaciation valley system with only some similarities to the present-one flowed in a northwesterly direction. There is a long hiatus in the evidence from the end of the glaciation to the beginning of the formation of the Calnozoic Kalahari Basin. The most significant feature of that intermediate period, is a large meteorite impact which occurred near Morokweng at the J-K boundary. The Cainozoic evolution of the Molopo drainage has been strongly influenced by both tectonics and climatic change. Tectonics, which include both the initial formation of the Kalahari Basin and Neogene warpings of the intra-continental axes of uplift, caused the interruption of a pre- Kalahari southward flowing drainage system, an extended upper Molopo, the existence of the Molopo as an endoreic system for an extended period of time, and a westward shift of the entire Molopo drainage system. Progressively more arid conditions interrupted by humid climatic pulses of decreasing intensity have occurred since the Cretaceous. The aridifying conditions caused the existence of playa-like conditions over long periods oftime in the back-tilted section of the proto-Molopo. This was followed by a rapid sediment infilling of the sub-basin and a major rejuvenation phase, which caused the incision of the Molopo River into the duricrusted sediments of the Kalahari Group, and the re-establishment of the Molopo River as an exoreic drainage system in its present position. Rock-cut terrace remnants in the upper Molopo give evidence of much smaller climatic changes during the Quaternary. There has been no integrated flow in living memory.

South African grasslands are under-conserved and there is a need to expand conservation efforts beyond the boundaries of protected areas. While communal grasslands have conservation potential they are generally over-utilized and the impact of communal land-use on biodiversity is poorly studied. At the same time there is pressure on protected areas to allow for the sustainable utilization of biodiversity. The aim of this study was to examine the impact of communal land-use on various components of biodiversity and to make recommendations regarding communal use of protected areas. A fence-line study was conducted to assess the impact of eight years of controlled communal land-use on biodiversity in the uKhahlamba-Drakensberg Park. The communally used land (referred to as the lease land) which was used for controlled grazing as well as plant collection was compared with land under formal conservation. Vegetation was sampled using the importance score method and veld condition assessments. Selected invertebrate taxa were sampled using sweep netting, colour pan traps and transects and were identified to morphospecies level. Multivariate statistics revealed that sites generally grouped according to landscape position rather than land-use. No significant differences were found in diversity, evenness, richness or veld condition between the lease and conservation land. However, more than twenty-five percent of vegetation and invertebrate species were found exclusively in the lease or conservation land, suggesting that different suites of species were supported by the two landuses. Four alien plant species were found exclusively in the lease land, while one vulnerable and one rare plant species were found only in the conservation land. Further research is required to assess whether biodiversity was diminished by controlled communal. While the lease concept may offer potential as a low-use buffer zone, localised damage from cattle paths and weak enforcement of grazing agreements were areas of concern. Keywords: communal grass)ands, grassland flora, grassland invertebrates, transfrontier park.
Thesis (M.Env.Dev.)-University of KwaZulu-Natal, Pietermaritzburg, 2004.

A dissertation submitted to the Faculty of Science, University of the Witwatersrand, Johannesburg, in fulfilment of the requirements for the degree of Master of Science. Johannesburg, 2014.
This thesis presents data collected during the 2012 and 2013 recording of painted sheep imagery from five painted rock shelters in the northern Drakensberg, KwaZulu-Natal, South Africa. Through studying the micro- and macro-context of these paintings, I try to understand their presence in the rock art here. Paintings of sheep are believed to have been made by San hunter-gatherers and thought to be relatively old. Using multiple strands of evidence from the rock art, the excavated record, ethnographies, and drawing on human-animal theory, I explore when the sheep were painted, whose sheep were painted and for what reason.

The geomorphology and dynamics of the Mfolozi River floodplain and estuary, located in the subtropical region of northern KwaZulu-Natal, South Africa, were considered with respect to existing models of avulsion and alluvial stratigraphy. The Mfolozi River floodplain may be divided into regions based on longitudinal slope and dominant geomorphic processes. Confinement of the Mfolozi River above the floodplain has led to the development of an alluvial fan at the floodplain head, characterized by a relatively high sedimentation rate and avulsion frequency, at a gradient of 0.10%. The lower floodplain is controlled by sea level, with an average gradient of 0.05%. Between the two lies an extremely flat region with an average gradient of 0.02%, which may be controlled by faulting of the underlying bedrock. Avulsion occurrences on the Mfolozi floodplain are linked to the two main zones of aggradation, the alluvial fan at the floodplain head, and toward the river mouth in the lower floodplain. On the alluvial fan, normal flow conditions result in scour from local steepening. During infrequent, large flood events, the channel becomes overwhelmed with sediment and stream flow, and avulses. The resulting avulsion is regional, and affects the location of the channel from the floodplain head to the river mouth. Deposits resulting from such avulsions contribute significantly to the total volume of sediment stored in the floodplain, and tend to persist for long periods after the avulsion. Contrastingly, on the lower floodplain, reaching of the avulsion threshold is not necessarily linked to large flood events, but rather to long-term aggradation on the channel that decreases the existing channels gradient while increasing its elevation above the surrounding floodplain. Resultant avulsions tend to be local and do not contribute significantly to the overall volume of floodplain alluvium.

Terracettes are a widely occurring form of micro-relief found throughout regions displaying various climatic and environmental conditions. Much speculation surrounds the processes responsible for their formation and development. An investigation of these micro-forms, their associated soil physical properties, sustaining mechanisms, and their relationship to slope stability was undertaken in Giant's Castle Game Reserve, KwaZulu - Natal Drakensberg, South Africa. The study showed that relationships between terracette morphology and soil physical properties within the Reserve are few, and that current soil conditions cannot be used to infer process related to terracette formation. However dry bulk density data indicated that soil creep is the dominant formative mechanism within the Reserve. Throughflow at riser surfaces was the dominant sustaining mechanism, with needle ice growth, wind, surfacewash and animal disturbance contributing minor retreat at both treads and risers. Aspect played an important role in determining soil physical characteristics. It was inferred that terracettes imparted stability to the slopes on which they are found, and with continued retreat at both treads and risers the slope was again placed under conditions of instability.
Thesis (M.Sc.)-University of Natal, Pietermaritzburg, 1998.

The Bell River in the Eastern Cape Drakensberg of South Africa has shown recent signs of channel instability as evidenced by avulsion, sinuosity reductions, gradient steepening and general channel instability. Analysis of rainfall data did not provide evidence for progressive long term change in rainfall pattern for the catchment. However, annual and seasonal rainfall cycles with variance peaks every 16-19 years were found, from which it can be inferred that flood events following years of below average rainfall may cross the threshold limit for channel stability. Channel instability is often followed by a major flood event after sustained low rainfall periods, a sequence referred to as the Flood and Drought Dominated Regimes by Warner (1987). Evidence presented also indicates an increase in catchment erosion in the past century with attendant sediment production increases to the channel. This may be due to catchment land use and management practices (following settlement by commercial farmers) superimposed on long term climatic changes. The conclusions are that catchment and channel processes are inseparable, and that disequilibrium in the catchment will be transferred to the channel.

The Sani Pass in the Natal Drakensberg is situated in the north-eastern sector of the Lesotho Highlands which forms a major Karoo-age basaltic massif in the Karoo Igneous Province. The volcanic section exposed in the pass is approximately 800m thick, and comprises a succession of regularly stratified, massive and amygdaloidallavas which were extruded mainly by fissure-type eruptions. Dolerite dykes, which now occupy thefissures,form a network ofpredominantly NE-SW and NW-SE trending topographic features. During post-eruption cooling hydrothermal solutions percolated through the volcanic succession and produced an amygdale zonation which was controlled predominantly by ambientpressure and temperature conditions. An original maximum thickness of 1 820m of the volcanic succession has therefore been estimated and an average fossil geothermal gradient of 111° C/km is conceived to have persisted during amygdale formation. New electron microprobe data are presented for the silicate phases in the Sani Pass basalts and dolerites. These data do not effectively separate the Sani Pass volcanic succession into different geochemical units. Microprobe analysesfor olivine, albeit limited, are in the forsterite range and indicate that a proportion of olivine in the high-MgO basalts is due to cumulus enrichment. The pyroxenes are predominantly augite and minor pigeonite, with some ofthe augites displaying a tholeiitic trend similar to that recognised at Skaergaard. Plagioclase is mainly in the labradorite to bytownite range, the phenocrysts being slightly enriched in anorthite compared to the groundmass. The use ofwhole-rock geochemistry for 67 basalts and 8 dolerites has permitted the recognition of five geochemically distinct magma types, namely, the Giant's Cup, Agate Vale, Sakeng, Mkhomazana and the Phinong. The Phinong basalts comprise the upper two-thirds ofthe volcanic succession and although are generally homogeneous, there is a slight tendency for the more evolved rocks to be found higher up in the stratigraphic sequence. The remaining magma types precede the Phinong succession and are generally enriched in silica and have higher Zr/Nb and lower PfZr ratios than the Phinong basalts. Within the pre-Phinong succession the Giant's Cup basalts are generally depleted in the compatible elements, while the overlying Agate Vale basalts are enriched in incompatible elements. Except for a marginally lower Na20 and Sr content, the chemistry ofthe Sakeng basalts is variable, generally overlapping with the other magma types. The Mkhomazana basalts are slightly enriched in MgO, Ni, Cr and Sc compared to all other pre-Phinong basalts. The dolerites in the area adjacent to the Sani Pass are geochemically similar to the Phinong basalts. The Phinong magma type is considered to be equivalent to the Lesotho magma type, based on their geochemical and stratigraphical similarities. In terms ofdiscriminant diagrams the Giant's Cup, Sakeng and Mkhomazana basalts generally show some compositional overlap with the Phinong, or plot in incoherentfields, but the Agate Vale basalts are distinctly different and might indicate a new magma type within the Karoo Central area. Broad compositional overlap between the Phinong basalts and those preserved at Kirwan and Heimefrontfjella, Antarctica, indicates juxtaposition of Antarctica along the southern African east coast in a reconstructed Gondwanaland. Petrogenesis of the Sani Pass basalts has been examined in terms of alteration, open and closed system fractional crystallization, partial melting procesess and a heterogeneous source. Although limited alteration and conduit contamination have occurred, the most feasible mechanism responsible for the geochemical variation lies in the existance ofinhomogeneities in the upper mantle at the time ofgeneration of the Sani Pass magmas.
Thesis (M.Sc.)-University of Durban-Westville, 1992.

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, 2016.
This dissertation examines the role of remote sensing on rock art survey and is motivated by two key objectives: to determine if remote sensing has any value to rock art survey, furthermore if remote sensing is successful to determine if these individual remote sensing components can contribute to a predictive (site locating) model for rock art survey. Previous research effectively applied remote sensing techniques to alternate environmental studies which could be replicated in such a study. The successful application of google earth imagery to rock art survey (Pugin 2012) demonstrated the potential for a more expansive automated procedure and this dissertation looks to build on that success. The key objectives were tested using three different research areas to determine remote sensing potential across different terrain. Owing to the nature of the study, the initial predictions were formulated using the MARA database – a database of known rock art sites in the surrounds of Matatiele, Eastern Cape – and were then applied to surrounding areas to expand this database further. Upon adding more sites to this database, the predictions were applied to Sehlabathebe National Park, Lesotho and then 31 rock art sites in the areas adjacent to Underberg. The findings of this research support the use of predictive models provided that the predictive model is formulated and tested using a substantial dataset. In conclusion, remote sensing is capable of contributing to rock art surveys and to the production of successful predictive models for rock art survey or alternate archaeological procedures focusing on specific environmental features.
LG2017

Submitted in fulfilment of the requirements for a Master’s Degree in: Tourism and Hospitality Management, Durban University of Technology, 2017.
This thesis discusses the concept of community participation and tourism development in KwaZulu-Natal using a case study of the Didima Resort and Umhlwazini community in Bergville, Drakensberg. In order to examine the research topic, the thesis scrutinizes the following key concepts: community participation in tourism development; tourism development initiatives for the local community of Umhlwazini; and, the contribution of tourism development towards community enhancement. The research was guided by four research objectives: (1) To investigate the level of understanding and awareness that the Umhlwazini community have regarding tourism development and the importance of community participation; (2) To investigate whether there is active community participation and whether there are tourism development initiatives or practices the resort authority is offering to the local community; (3) To ascertain strategies employed by Didima Resort to encourage maximum participation of communities for development of tourism at Umhlwazini; and, (4) To identify problems that hinder the community's participation in tourism development at Umhlwazini. The outcomes from the interviews indicate that the majority of the Umhlwazini community members are willing and interested in participating in the development of the tourism initiatives happening at Didima Resort and within their community. Currently, the community's participation in tourism development in their area is predominantly at the level of temporary jobs which are occasionally offered to unskilled labour. Work opportunities for skilled workers are non-existent so that not even a single member from the community is part of the Didima Resort management team. Recommendations arising from the study include but are not limited to the following: There must be a vigorous, selfless and mutual cooperation between the following role players; Amangwane Traditional Council, Ezemvelo KwaZulu-Natal Wildlife (Didima), Ingonyama Trust, Okhahlamba local municipality and the community of Umhlwazini. This association will ensure that the interests of the community are taken into account and that the community is part and parcel of any tourism development projects taking place in the Umhlwazini area. There is an obligation for community enhancement programs such as tourism awareness campaigns and tourism seminars in the Umhlwazini community. Ezemvelo KwaZulu-Natal Wildlife (EKZNW) must put more effort into advertising and promoting community products such as bicycle hire and handcraft work. That effort can increase the visibility and sales of such community products. Community problems appear to be more noticeable than benefits. Some of the problems identified are: the lack of jobs from Didima Resort; no improvement in the infrastructure of the community; local artistic talent is not utilised during mega events happening at Didima. The lack of tourism awareness and education was identified as two main causal factors that impede community participation in tourism development, as well as the breakdown of communication between Ezemvelo KwaZulu-Natal Wildlife and Umhlwazini leadership (traditional council and contemporary political councillor). According to the outcomes derived from analysis of the data from interviews, this research study concludes that local community members desire to play an active role in the tourism development process of Didima and Umhlwazini. In general, community members want to see decisions about tourism development in their area made co-operatively by Ezemvelo KwaZulu-Natal Wildlife, Okhahlamba municipality and local leaders (Amangwane Traditional Council) in consultation with the local community of Umhlwazini. They also want to be recipients of tourism benefits and want transparency regarding the community levy fund which is meant to support community projects. This research study further concludes that there is great potential for community participation in tourism development initiatives at Umhlwazini community and Didima Resort. There are various tourism opportunities for the community which can be explored including a traditional restaurant and a cultural village which would benefit the community immensely. The community of Umhlwazini needs to be empowered with knowledge, business skills and financial assistance to start business ventures. It is only when the local community benefits financially that their participation in tourism development will become meaningful to them.
M

Wetland degradation, which includes deterioration in functional performance and erosion, is a problem around the world. This has engendered a quest for causes and attempts to prevent the problem or to rehabilitate wetlands already degraded or undergoing degradation. The Craigieburn wetland system in Mpumalanga Province, South Africa has undergone erosion due to two downstream discontinuous gullies that have drained and considerably reduced the size of the wetland system. Measurements from 1954 to 1997 aerial photographs showed that over 40 years, the upper gully migrated headward over a distance of 30 m, while the lower gully eroded 522 m headward raising the question as to what caused their erosion? Prior to this study, the predominant view was that human activities, namely poor land use management within the wetland system, increased human occupation, and overgrazing on the adjacent catchment that caused a reduction in vegetation cover, were responsible for this wetland erosion. Detailed field observation, aerial photograph interpretation, soil analyses for mineralogy, chemistry and particle size distribution, landscape mapping, dumpy level survey of the wetland valley and statistical analysis were undertaken to establish the relationships between gullying and possible contributing factors. Human impacts on wetland gully development between 1954 and 1997 were estimated using the number of individual homes, and total lengths of footpaths, animal tracks and dirt roads. Agricultural activities and the stocking rate of livestock were excluded due to the poor quality of aerial photographs and lack of historical records. Results of multiple regression correlating lengths of the two gullies (upper and lower gullies) and the sum of these human factors gave a high correlation (adjusted R² = 0.92 and 0.90, respectively) but a low significance (p = 0.18 and 0.21, respectively). However, time has played a significant role in the erosion of both the upper gully (R² = 0.82, p = 0.02) and the lower gully (R² = 0.98, p = 0.02) at Craigieburn. X-ray diffraction and X-ray fluorescence spectrometry of weathered parent materials showed that the area has undergone deep weathering, supplying sediments to the wetland valley through surface run-off. The accumulation of these sediments resulted in localized over-steepening of certain sections of the valley floor with raised gradients of 0.0336 and 0.0337 at the two headcuts relative to the upper and lower non-eroding sections with lower gradients. These localized steep sections increased flow velocity and stream power and therefore stream erosivity thus triggering gully erosion. In addition to localized areas of raised valley floor, results from multiple regression showed a significant relationship (p = 0.002) between areas of earthflow scars and gully length, especially at the lower gully, thus further suggesting that physical factors are largely responsible for gully erosion at Craigieburn. Long-term climate change has resulted in the formation of two terraces, an older, D1 (USU-760, 1.67 ± 0.89 ka) and a younger, D2 (USU 761, 0.32 ± 0.08 ka). The former probably eroded during the medieval warming around 1230 AD while the younger terrace, which likely formed during the last half of the Little Ice Age, has been eroding since the renewed warming thereafter. This erosion has been exacerbated by short-term periodic or seasonal climatic changes, especially episodic summer rainfall events, which have likely played a key role in the headward migration of the two gullies. The result has been shrinkage of the wetland system by about 15 m on both sides of the valley, leaving behind a greyish soil colour indicating wet and reducing conditions in the past. These, together with dried relict mottles left behind in the soil matrix at the margin of the shrunken wetland system suggest past seasonal fluctuation of the water table engendering the belief that the wetland system once extended beyond its present limit. The overwhelming contribution of these physical factors, in addition to the fact that the two gullies predate human occupation of the study area catchment and environs, strongly argues for their responsibility in gully initiation and development at Craigieburn. Human presence and activities, which only became evident in the catchment from the 1950s onwards, may be secondary contributory factors. This conclusion encourages a rethink of previous views that human occupation and activities are solely responsible for this wetland gully erosion at Craigieburn and provides a rationale for including physical processes and climate change as factors when investigating causes of wetland erosion elsewhere. Such an understanding should be used to inform any rehabilitation or conservation efforts that are related to wetland ecosystems.
Thesis (Ph.D.)-University of KwaZulu-Natal, Westville, 2011.

M.Sc.
This study concentrates, not only on the physical origin of the pans, but also attempts to define certain guidelines which will contribute to an improved urban environment in the future. The series of pans on the East Rand form part of the greater Highveld pans, which extends in an easterly direction to eventually link up with the Lake Chrissie pan series. The study is however limited to those pans appearing on the 1: 50 000 topographical map 2628 AB Benoni ...

M.A.
Pan are naturally occurring depressions or closed basins and play a very important role in ecosystems. The East Rand is characterized by more than one hundred pans dotting its landscape. The impact of urbanisation on these pans is significant. To determine exactly how the characteristics of the pans on the East Rand has changed, a comparison was done between the characteristics and utilization of the pans in 1992, as then described by Le Grange (1992) and the current situation in 2003. Water samples were also collected over a period of three months and analysed in the laboratories of Rand Water. The current utilization of the pans leaves much to be desired. Informal settlements, industries, residential areas and mine dumps are all found on the pan floors. Large waste dumping sites are developing at five out of the 19 pans in the study area. This has severely negatively affected the water quality within the pans, and the quality of bird life at thee pans. Continuous research is needed from government and private organisations on the pans found on the East Rand to improve their current quality and condition. Responsibility and proper management strategies must be implemented to protect the pans from negative human impacts.