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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
41

Geological control of aquifer properties of the Chuniespoort Group in the Klip River Valley and Natalspruit Basin, Transvaal

Foster, Michael Benedict John 08 March 2013 (has links)
The aquifer of the study area occupies an escarpment and low lying limestone plain, and exhibits a Vaal River type karst. The four dolomitic formations present fall into two distinct aquifer forming types; chert poor units and chert rich units. The chert poor units of the Oaktree and Lyttelton Formations were deposited in a subtidal environment and were probably dolomi tised in a migrating schizohaline environment during basin subsidence and shoreline trangression. The chert rich units of the Monte Christo and Eccles Formations were deposited in the shallow subtidal to supratidal zones and the interbedded chert and dolomites may result from minor cyclical marine trangressions and regressions or be a geochemical response to the periodic flooding of freshwater carbonate and flats and tidal deltas. These fundamental geological differences are reflected in correspondingly different development of karst. Transmissive zones in the chert poor units are generally discrete solution features in massive dolomite, 1 m to 2 m thick. Transmissive zones in the chert rich units comprise thick (up to 60 m) and extremely weathered chert with a high void content resulting from the dissolution of carbonate material. The relative importance of various geological features to the development of the karst was assessed using information from two extensive hydrogeological investigations of the area. From the results it bas been concluded that lithostratigraphy, including the occurrence of palaeokarstic horizons, is the major control of aquifer properties. All other geological features are of lesser importance but may nevertheless be associated with enhanced transmissivi ties in any given unit. Faults and lineaments are the structural features most widely associated with highly transmissive zones. The knowledge gained in this study is applicable elsewhere as the principal hydrogeological characteristics of the study area are common to many of the Chuniespoort Group aquifers in the Pretoria - Witwatersrand - Vereeniging Region.
42

An erosion and sediment delivery model for semi-arid catchments

Bryson, Louise Kay January 2016 (has links)
Sedimentation has become a significant environmental threat in South Africa as it intensifies water management problems in the water-scarce semi-arid regions of the country. As South Africa already allocates 98% of available water, the loss of storage capacity in reservoirs and degraded water quality has meant that a reliable water supply is compromised. The overall aim of this thesis was to develop a catchment scale model that represents the sediment dynamics of semi-arid regions of South Africa as a simple and practically applicable tool for water resource managers. Development of a conceptual framework for the model relied on an understanding of both the sediment dynamics of South African catchments and applicable modelling techniques. Scale was an issue in both cases as most of our understanding of the physical processes of runoff generation and sediment transport has been derived from plot scale studies. By identifying defining properties of semi-arid catchments it was possible to consider how temporal and spatial properties at higher levels emerged from properties at lower levels. These properties were effectively represented by using the Pitman rainfall-runoff model disaggregated to a daily timescale, the Modified Universal Soil Loss Equation (MUSLE) model incorporating probability function theory and through the representation of sediment storages across a semi-distributed catchment. The model was tested on two small and one large study catchment in the Karoo, South Africa, with limited observed data. Limitations to the model were found to be the large parameter data set and the dominance of structural constraints with an increase in catchment size. The next steps in model development will require a reduction of the parameter data set and an inclusion of an in-stream component for sub-catchments at a larger spatial scale. The model is applicable in areas such as South Africa where water resource managers need a simple model at the catchment scale in order to make decisions. This type of model provides a simple representation of the stochastic nature of erosion and sediment delivery over large spatial and temporal scales.
43

Analysis of temporal and spatial variations in water storage by means of gravimetric and hydrologic methods in the region around the South African gravimetric observation station

Mahed, Gaathier January 2013 (has links)
This work examines the use of gravity data and its application to subsurface water reservoirs in the immediate vicinity of the South African Geodynamic Observatory, Sutherland (SAGOS), situated in a semi-arid region of the Karoo region of South Africa, and underlain by the Karoo sedimentary rocks intruded by dolerite dykes and sills. SAGOS houses the only supergravity metre (SG) in Africa, and this thesis sets out to test its use in monitoring groundwater dynamics using hydrological and gravity data. The main aim of this work is the application of the SG data, in conjunction with hydrological data, to better understand episodic recharge of subsurface reservoirs. The importance of water as a resource, globally and specifically the Karoo, is reviewed in conjunction with supply and demand of water. This is to contextualise the socio-economic, technical as well as policy issues related to water resource management. Applicable technologies for water resource management and efficient water use are highlighted and the application of gravity to hydrology is introduced, including satellite as well as ground based tools. In addition, arid zone hydrology as well as recharge and its mechanisms are analysed in order to better understand these processes when examined from gravity measurements. Issues related to understanding flow within the vadose zone as well as in secondary aquifers are examined, and gravity residuals and subsurface hydrology are highlighted. Thereafter, a conceptual groundwater flow modelof the study area is developed using multiple tools. First, the geology around SAGOS was mapped using SPOT 5 imagery and then ground truthed. Second, stable isotopes and water chemistry analysis was undertaken on water samples from selected boreholes. The results allude to preferential flow acting as the main mechanism for groundwater recharge. Follow-up pump-tests illustrate that fracture connectivity is greatest at close proximity to the dyke. Soil mapping, using aerial photography was also undertaken. Duplex soils, enriched with clay at depth, dominate the study area. Using in-situ infiltration tests, it is shown that the alluvium, which lines the river beds, has a higher hydraulic conductivity than the other soils, confirming that these streams act as preferential conduits for subsurface recharge. Precipitation events were correlated against gravity residuals at 4 wells, over different time periods. The results are examined using time series analyses. Gravity residuals from well SA BK07, over a period of 24 hours after the rainfall event, delineate instances of negative correlations, as well as strong positive correlations (of up to 0.9). On the whole however, correlations between gravity and groundwater at SA BK07 are variable and weak, and in conjunction with water level measurements and water chemistry, the data suggest that this well is located in a dynamic conduit (throughflow) and not in a permanent groundwater reservoir. By contrast, other wells show strong positive correlations between gravity residuals and water levels following episodic recharge events for a later time series. Correlations between the water levels and gravity residuals in wells SA BK04, SA BK05 and SA BK 01 are in excess of 0.7 for specific rainfall events. In summary, the results suggests that gravity is an excellent tool for measuring episodic groundwater recharge within the immediate vicinity of the SAGOS. This implies that gravity can aid in monitoring groundwater losses/gains in arid and semi-arid areas. Recommendations for future work are highlighted at the end; these include the possible use of hydrological modelling of reservoirs at various scales and then comparing these results to the SG as well as GOCE and GRACE satellites data, and then improving numerical modelling of the groundwater dynamics for sites like Sutherland and the surrounding arid Karoo region, where sparse water shortages, and potential pollution related to fracking for shale-gas, are likely to compete with established water needs for farming and human consumption. It is also suggested that the gravity modelling be examined to better understand site specific scenarios and thus aid in improving the processing of the gravity signal.
44

A comparison of the values of water inflows into selected South African estuaries : the Heuningnes, Kleinmond, Klein, Palmiet, Cefane, Kwelera and Haga-Haga

Dikgang, Johane January 2008 (has links)
“An estuary is a partially or fully enclosed body of watera) which is open to the sea permanently or periodically; b) within which the sea water can be diluted, to an extent that is measurable, with freshwater drained from inland” (National Water Act, 1998). Estuaries are ecologically important because they are habitats for birds, fish and plants and they are valuable because they provide human beings with food (fish) and recreational pleasure in the form of unique views, bird watching and opportunities for swimming and boating. It is in this context that they may be said to provide economic goods and services for current and future generations. The provision of these services is dependent on the inflow of freshwater into estuaries. The problem with estuarine freshwater demand is that estuaries are the ‘last in line’, literally and perhaps in the typical prioritisation of human wants by government. Clearly it is imperative that the value of freshwater inflows into estuaries be determined and these values incorporated into catchment management decision making. South African estuaries have in the past mainly been managed on a piecemeal basissometimes in the interest of fishermen, sometimes property development owners and sometimes other local interest groups. This situation changed with the National Water Act of 1998. One of its objectives was to address the mismanagement and inadequate research about water inflow impacts on estuaries (Allanson and Baird, 1999). The global warming phenomenon is going to negatively affect estuaries and put more pressure on the availability of freshwater inflows into estuaries, as well as the availability of drinking water. The majority of South African estuaries are temporally open/closed and experiencing reduced functioning due to reductions of freshwater inflow to them. Given the overwhelming evidence available on the significance of freshwater inflow to estuary functionality, it is clear that an important component of catchment management is the allocation of river water into estuaries. Economic guidance comes in the form of comparisons of value. There are seven estuaries for which values were generated, the Heuningnes, Kleinmond, Klein, Palmiet, Cefane, Kwelera and Haga- Haga. All of the seven estuaries fall in areas characterized by warm temperate climates and low rainfall levels. Estuary services, like many other environmental services, are not traded in the markets. For this reason, in order to estimate their value, reference must be made to proxy markets, and methods of valuation have to be employed that can use proxy market information - like the contingent valuation method (CVM), the travel cost method (TCM) and the hedonic pricing method (HPM). For the purpose of this research the CVM was preferred because it is best suited to including passive or nonuse values. The CVM estimated values are compared with other values generated using the TCM. The information required to make the CVs was gathered through surveys in at the seven selected estuaries from December 2005 to April 2006. From this information sample mean and median Willingness to Pay (WTP) values for freshwater were calculated, socio economic profiles were generated, the importance that respondents attached to various activities in the estuary was deduced, and, Tobit and Ordinary Least Squares (OLS) statistics models were used to predict household WTP. The Total WTP (TWTP) for each estuary was obtained by multiplying the median WTP by the total number of households that use the estuary. The median WTP is preferred to the mean WTP because of a skewed bid distribution of WTP among the users. The value per m3 of freshwater was obtained by dividing the TWTP by the total forecast reduction in water inflows into the estuary.
45

A conjoint choice experiment analysing water service delivery in three Eastern Cape Municipalities

Hosking, Phillipa January 2011 (has links)
This study considers the nature of South African municipal water service delivery, and how marketing strategies can provide a framework for better management of this service. It reflects on the elements that guide municipal decision making and evaluates user preferences for levels of the municipal “water service mix” by employing conjoint analysis. Particular attention is paid to consumer willingness to pay for improvements in the “water service mix”. The study argues that the values municipal consumers attach to the variables of the water service mix need to be better incorporated into decision making regarding water service delivery, and that conjoint analysis is an informative method to assist in generating this information. The study outlines a water service marketing challenge and methods of research followed to deal with it (Chapter One) and the nature of the laws and institutions governing water service provision in South Africa (Chapter Two). The task of providing water services is delegated to Water Service Providers (municipalities). The key variables of the water service mix from the consumers perspective include; quality of the water, rate of flow from tap, interruption of water flow, sewerage disposal, assurance of supply, and water service tariffs (Chapter Three). The study covers the areas of Amathole, Kouga and Nelson Mandela Bay Municipalities' (Chapter Five). The method of marketing analysis applied is conjoint analysis, alternatively known as choice experiment analysis. An overview of the method is provided and its application to three samples of one hundred residents at each of the study sites is described in Chapter Four. The responses of the three hundred residents provide the basis for the results. Respondents were requested to make a series of choices between alternative water service mixes consisting of six variables differentiated by three levels (Chapter Three). In making these choices they implicitly compared and weighed up the relative worth of the selected variables against each other. The findings of the analysis were diverse (Chapter Six); two of the three estimated models did not yield significant results. An interpretation of these results showed that the respondents of the Kouga municipality were willing to pay R65.05 more (per 10 xii Kilolitres of water) than their current monthly tariff for a marginal improvement in water quality, R57.29 more (per 10 Kilolitres of water) per month for a marginal improvement in sewerage disposal and R21.90 (per 10 Kilolitres) per month for marginal improvements in assurance of water supply. Findings showed that willingness to pay for reduced interruptions and improved flow rates was lower and not as highly valued as the abovementioned variables. Most of these findings were consistent with similar international and national studies showing their reliability. Although there has been significant improvement in extending the reach of the network since 1994, the standards of water service provision in South African municipalities do not appear to have improved. The results of this study mirror a number of concerns that have been expressed about the standards of service, particularly sanitation (in publications like the Green Drop Report). Municipal service delivery in these areas would appear to be constrained by a number of issues including a lack of public involvement, legislation, limited financial resources and institutional capabilities. However, it is a service that is too vitally important to be allowed to deteriorate. Marketing analyses can make a valuable contribution to allocating and managing the scarce resources to best satisfy the consumers of water services (Chapter Seven). When consumer orientation is formally introduced as the main objective into the thinking of the service provider, it becomes untenable to offer poor service delivery. But that is exactly what many municipalities appear to be doing. There is a need to get back to the basics – where the consumer is king. This analysis concludes that consumers want, above all else, assurance of water supply, a high quality of water, and safe environmentally sensitive disposal of waste water. It is recommended that municipalities not lose sight of the fact that price is an important part of the marketing mix. From the paying consumers perspective, when the government incorporate too many other considerations into pricing of water services they are, in effect, disengaging price from the marketing mix by not being sensitive to consumer needs. This approach shows a weak marketing strategy, and may result in dissatisfied consumers who may become unwilling to pay for their water services – an outcome that the researcher would discourage.
46

An analysis of the factors influencing the provision of water in the Buffalo City Municipality, province of the Eastern Cape

Zwelibanzi, Mantombi Elizabeth January 2011 (has links)
Factors affecting the provision of water constitute a great challenge to water officials not only in Buffalo City Municipality but also globally. Interviews form the basic data collection instrument used to provide empirical evidence to the objectives of the study. The objectives of the study are: To evaluate the underlying challenges encountered by water sector Engineers; To evaluate the role of municipal water sector officials in the provision of clean water; To analyse the factors influencing the provision of water in Buffllo City Municipality. Recommendations are provided which could assist Buffalo City Municipality in addressing the challenges affecting the provision of water as follows: The involvement of national and provincial governments in order to improve the Buffalo City Municipal infrastructure and capacity building is highly recommended. Power failure and water interruptions caused by mechanical problems and natural disasters, are further municipal challenges that need to be addressed irrespective of financial constraints. Public and private sector sponsors can be approached to join the initiative. Informal settlements should be formalised and limited to a certain number of people per site or household, depending on the infrastructure. If the infrastructure is not conducive they should be relocated elsewhere. Public and private sector sponsors should offer assistance to Buffalo City Municipality to develop the required water skills, by financing water officials who are interested in furthering their education at tertiary level. Public consultation, through meetings and public forums, and public participation, by the street committees and police forums, are recommended. Coupon systems for basic services like water and electricity for all residents is highly recommended. A generator for the municipal water sector is needed. This will overcome the power failure problem. The provision of water is affected by power outages as water equipment needs electricity to be able to operate. Installation of a water plant in Buffalo City Municipality‟s main dam, the Maden dam, that is supposed to supply King Williams town and the surrounding areas directly.
47

Hot water consumption in South Africa

Muya, T.M. 10 September 2012 (has links)
M.Ing. / A one-year investigation on hot water consumption was conducted in South African developed and developing communities of Johannesburg to determine the personal and household average daily consumption of hot water as well as the average hourly (in summer and in winter) and monthly patterns. The motivation for this research project was to provide to engineers and water heaters manufacturers reliable experimental data on hot water consumption from various categories of dwellings. The existing sources of information in South Africa being extremely limited and results of estimations. The necessary information was collected from hourly and monthly measurements taken by monitoring hot water systems in different dwellings including, houses (300 units), traditional houses (90 units), shacks (200 units), apartments (123 units), townhouses (90 units). For the purpose of this study, the selected (not statistically) dwellings were classified into three categories, which are: high-density dwellings representing the developing communities, medium-density and low-density dwellings which represent the developed communities. The results of measurements show that, in general, people living in developed communities (low-density dwellings) use at least 1.4 times more hot water than those of developing communities (high-density dwellings). The patterns of hot water consumption have been determined for monthly and hourly consumption. The former is divided in four sections: summer weekdays, winter weekdays, summer weekends and winter weekends. The differences between sections are the specific times of peaks and the consumption. The results of this study should be of great assistance to engineers and water heaters designers in analysing existing systems for performance improvement, and in sizing more efficient and suitable systems to South African use.
48

A critical analysis of water supply service delivery in the Mutale Municipality

Tangulani, T. M. 11 October 2013 (has links)
MPM / Oliver Tambo Institute of Governance and Policy Studies
49

An evaluation of water supply in rural areas of Limpopo Province: case study of Gaba and Tshifudi

Makomoto, Gladys Stella 11 October 2013 (has links)
MPM / Oliver Tambo Institute for Governance and Policy Studies
50

Thirsty for change: water challenges and opportunities in South African businesses

Jeram, Dyani January 2019 (has links)
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, 2019 / Water is a key element linked to challenges such as food security, economic development, energy generation and climate change. South Africa experienced its driest year on record in 2015, together with one of the largest cities, Cape Town, almost running out of water in 2018. The likelihood of increased drought in the future coupled to climate risks makes it imperative to attend to water security concerns within the country. The business sector needs to pay more attention to water issues given its reliance on water for operation. This study explores how South African companies that are dependent on water respond to water security concerns linked to increased demand and variability. Focusing on the potential of the CDP Water reporting process to promote improved water stewardship practices. A mixed methods approach is used including a detailed investigation of CDP Water report data and interviews. Companies are unique in their responses, their perception of water risk hence determines their responses to the risk. Many companies showed misalignments between their company strategy, governance and practice in water decision making that further calls into question their water stewardship in addressing water security concerns. Although water stewardship is highlighted as an opportunity for various companies, engagement in practices that promote stewardship is low. In the pursuit of water stewardship practices and improved water management, context becomes key. By companies conducting comprehensive river basin assessments, it assists in addressing and engaging water risks in a local context. Beyond CDP reports and interviews, an underlying outcome has emerged that calls for effective sustainability/ environmental strategic planning in environmental departments within companies. Communication becomes an essential tool even though creating a business case around risk is not unique to water. An emphasis is then needed at Board level on effective leadership within a company to transform the way they view their water related risks and turn them into opportunities. To bring these findings together, archetypes were created based on company ‘water stewardship readiness.’ The archetypes encompassed the likelihood of companies engaging in water stewardship practices as this is seen as one of the best ways forward for business to assist in securing water in the country. The notion of a water champion to tackle water related risks and lead opportunities brings to light the value of education and creating individuals, regardless of their field of interest, with the understanding and knowledge that resources such as water are limited. Environmental issues should be embedded within these individuals for appropriate decision making given the current state and future projections of not only water, but environmental concerns going forward. / TL (2020)

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