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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.
241

An assessment of selected non-water benefits of the Working for Water Programme in the Eastern and Southern Cape

Du Plessis, Lily Lozelle January 2003 (has links)
1.1 Background to, and motivation for, the study: The Working for Water programme (WfW) is a public works programme designed to clear South Africa of water-consuming invasive alien tree and plants, and to replace them with low water consuming indigenous species. This would prevent a loss of more than 4000 million cubic metres water per annum from the hydrological cycle (DWAF, 1998). The economic viability of the programme has been established in the Western Cape and Kwazulu-Natal (van Wilgen, Little, Chapman, Görgens, Willems and Marais, 1997; Gilham and Haynes, 2001), but questioned in the Eastern and Southern Cape (Hosking, du Preez, Campbell, Wooldridge and du Plessis, 2002). Hosking et al. (2002) investigated the economic case for the programme by performing a Cost Benefit Analysis (CBA), based on increased water yield and livestock potential, on six selected sites in the Eastern and Southern Cape, viz. Albany, Kat River, Pot River, Tsitsikamma, Kouga and Port Elizabeth Driftsands.
242

The role of capacity-sharing in South African water policy

De Lange, Willem Johannes 12 1900 (has links)
Thesis (MSc)--Stellenbosch University, 2002. / ENGLISH ABSTRACT: A vast literature on the incompatibility of socio-economic development and environmental conservation (also referred to as sustainable development) has developed over the past few years. This study takes on the form of a critical, problemdriven discussion and evaluation of the applicability and viability of the concept of capacity-sharing to the current South African water management regime. Within the study, the complexities involved in the shift from a supply- to demandoriented management strategy are examined in depth. This transition in strategy proves to be problematic for water policy makers and managers because of past management regimes and structures, measurement related problems, incorrect or insufficient definition of criteria needed for demand-oriented approaches and the emotional complexities regarding water use. Developments in water policy are currently at a point where problems are experienced regarding the practical implementation of proposed water demand-oriented policy. The concept of capacity-sharing is explained and discussed in detail, leading to the identification of the applicability to three of the most important problems (basic contradiction within the 1998 National Water Act, initial allocation for market adoption and equity within the market) faced within the transition towards a demand-oriented approach. This study found that the concept of capacity-sharing does hold applicability in addressing the above-mentioned three problems towards the transition to a demand-side management approach. Capacity-sharing, therefore, should be part of this timely transition and the state should make use of the advantages of this concept. To support this view, seven studies are proposed for further research to address the problems as mentioned in section 5.2 of the thesis. / AFRIKAANSE OPSOMMING: 'n Uitgebreide literatuur aangaande die onversoenbaarheid van sosio-ekonomiese ontwikkeling en omgewingsbewaring (ook volhoubare ontwikkeling genoem) het oor die afgelope paar jaar ontwikkel. Hierdie studie neem die vorm van 'n kritiese, probleemgedrewe bespreking ten opsigte van die toepasbaarheid en relevansie van die konsep van kapasiteitsdeling binne die orde van huidige Suid Afrikaanse waterbestuur, aan. Die vele aspekte van die klemverskuiwing van 'n aanbod- na 'n vraag-georiënteerde waterbestuur-strategie, word ook beklemtoon. Hierdie oorgang is problematies vir waterbeleid-formuleerders en bestuurders as gevolg van vorige waterbestuur-ordes en strukture, meetbaarheid georiënteerde probleme, foutiewe of onvoldoende definieering van watergebruik-regte en die emosionele kompleksiteite van water. Tans, word probleme rakende die praktiese implementering van voorgestelde vraag-georienteerde waterbeleid ervaar. Die konsep van kapasiteitsdeling word in detail verduidelik en bespreek waarvandaan die toepasbaarheid op drie van die belangrikste probleme (basiese kontradiksie binne die 1998 Nasionale Waterwet, aanvanklike verdeling van water gebruik regte vir opname binne die mark en die kwessie van regverdigheid binne die mark) vir die oorgang na 'n vraaggeoriënteerde strategie geïdentifiseer word. Die studie het bevind dat die konsep van kapasiteitsdeling wel relevansie ten opsigte van die bogenoemde drie probleme tydens die oorgang na 'n vraag-georiënteerde strategie, inhou. Kapasiteitsdeling behoort dus deel te vorm van die oorgangsfase na 'n vraag-georiënteerde water bestuur strategie en die staat behoort gebruik te maak van die konsep se voordele. Ter ondersteuning hiervan word sewe studies voorgestel vir verdere navorsing ten opsigte van die probleme soos geïdentifiseer in afdeling 5.2 van die tesis.
243

Perceptions of water scarcity: the case of Genadendal and outstations.

Noemdoe, Simone Beatrice January 2006 (has links)
<p>The water resources management regime has shifted from one focusing almost exclusively on augmenting supply to one where ensuring access, equity and sustainability are an integral part of the process. A growing demand for water and the fact that the amount of fresh water is constant raises the impression of water scarcity will occur. Indications are that the notion of access to water for basic needs as well as access to productive water underpins perceptions of scarcity. This thesis interrogated perceptions of scarcity in a small rural community in order to understand the role water can play in developing sustainable livelihoods.</p>
244

Challenges of water management at local government municipal level in the Eastern Cape of South Africa

Mulenga, Kasonde January 2017 (has links)
A research report submitted to the School of Civil and Environmental Engineering, University of the Witwatersrand, in partial fulfilment of the requirements for the degree of Master of Science in Engineering, Johannesburg, 2017 / Human beings depend on water not only for life itself but also for their economic wellbeing. Water resources play a cardinal role in the creation of everything that human beings produce. Post-apartheid South Africa is in the throes of incredible challenges. One of the more important challenges is access for all citizens to basic services. South Africa is doing this against a backdrop of strongly differential servicing that is its apartheid legacy, which has prompted many commentators to label South Africa a country of two worlds, more specifically, a developed world component and an impoverished developing world component. The challenge with respect to water is to ensure universal access in the context of the added hurdle of South Africa being a water-scarce country. The local municipalities of the Eastern Cape have been facing a number of challenges in the provision of clean, portable water to their communities. This has resulted in inadequate provision of water, meaning that not all communities have access to clean water 24 hours a day The overall objective for this study is to contribute to the body of knowledge available to the water sector about the management of sustainable water supply systems in municipalities, and determine the factors that have undermined the sustainability of water provision at a local government municipal level in the Eastern Cape Province of South Africa. In this research, the effectiveness of local governments, which act as water services authorities (WSA) and providers of water to the rural communities, is examined. To this end, a comprehensive literature review was conducted and data gathered to discover why there has been a failure in the provision of clean drinking water. The results of the research illustrate that institutional incapacity in rural municipalities and widespread poverty serve to undermine the sustainability of the local government sector and lead to breakdowns in services delivery. Measures are proposed that can be adopted to improve the current approaches of water supply in local municipalities. / CK2018
245

Water balance and soil erosion in the Brazilian Cerrado / Balanço hídrico e erosão do solo no Cerrado brasileiro

Oliveira, Paulo Tarso Sanches de 12 December 2014 (has links)
Deforestation of the Brazilian savanna (Cerrado) region has caused major changes in hydrological processes. These changes in water balance and soil erosion are still poorly understood, but are important for making land management decisions in this region. Therefore, it is necessary to understand the magnitudes of hydrological processes and soil erosion changes on local, regional and continental scales, and the consequences that are generated. The main objective of the study presented in this doctoral thesis was to better understand the mechanism of hydrological processes and soil erosion in the Cerrado. To achieve that, I worked with different scales (hillslope, watershed and continental) and using data from experimental field, laboratory, and remote sensing. The literature review reveals that the annual rainfall erosivity in Brazil ranges from 1672 to 22,452 MJ mm ha-1 h-1 yr-1. The smallest values are found in the northeastern region, and the largest in the north and the southeastern region. I found that the canopy interception may range from 4 to 20% of gross precipitation and stemflow around 1% of gross precipitation in the cerrado. The average runoff coefficient was less than 1% in the plots under cerrado and that the deforestation has the potential to increase up to 20 fold the runoff coefficient value. The results indicate that the Curve Number method was not suitable to estimate runoff under undisturbed Cerrado, bare soil (hydrologic soil group A), pasture, and millet. Therefore, in these cases the curve number is inappropriate and the runoff is more aptly modeled by the equation Q = CP, where C is the runoff coefficient. The water balance from the remote sensing data across the Brazilian Cerrado indicates that the main source of uncertainty in the estimated runoff arises from errors in the TRMM precipitation data. The water storage change computed as a residual of the water budget equation using remote sensing data (TRMM and MOD16) and measured discharge data shows a significant correlation with terrestrial water storage change obtained from the GRACE data. The results show that the GRACE data may provide a satisfactory representation of water storage change for large areas in the Cerrado. The average annual soil loss in the plots under bare soil and cerrado were 15.25 t ha-1 yr-1 and 0.17 t ha-1 yr-1, respectively. The Universal Soil Loss Equation cover and management factor (C-factor) for the plots under native cerrado vegetation was 0.013. The results showed that the surface runoff, soil erosion and C-factor for the undisturbed Cerrado changes between seasons. The greatest C-factor values were found in the summer and fall. The results found in this doctoral thesis provide benchmark values of the water balance components and soil erosion in the Brazilian Cerrado that will be useful to evaluate past and future land cover and land use changes for this region. In addition, I conclude that the remote sensing data are useful to evaluate the water balance components over Cerrado regions, identify dry periods, and assess changes in water balance due to land cover and land use change. / O desmatamento nas regiões de Cerrado tem causado intensas mudanças nos processos hidrológicos. Essas mudanças no balanço hídrico e erosão do solo são ainda pouco entendidas, apesar de fundamentais na tomada de decisão de uso e manejo do solo nesta região. Portanto, torna-se necessário compreender a magnitude das mudanças nos processos hidrológicos e de erosão do solo, em escalas locais, regionais e continentais, e as consequências dessas mudanças. O principal objetivo do estudo apresentado nesta tese de doutorado foi de melhor entender os mecanismos dos processos hidrológicos e de erosão do solo no Cerrado Brasileiro. Para tanto, utilizou-se diferentes escalas de trabalho (vertentes, bacias hidrográficas e continental) e usando dados experimentais in situ, de laboratório e a partir de sensoriamento remoto. O estudo de revisão de literatura indica que a erosividade da chuva no Brasil varia de 1672 to 22,452 MJ mm ha-1 h-1 yr-1. Os menores valores encontram-se na região nordeste e os maiores nas regiões norte e sudeste do Brasil. Verificou-se que os valores de interceptação da chuva variam de 4 a 20% e o escoamento pelo tronco aproximadamente 1% da precipital total no cerrado. O coeficiente de escoamento superficial foi menor que 1% nas parcelas de cerrado e o desmatamento tem o potencial de aumentar em até 20 vezes esse valor. Os resultados indicam que o método Curve Number não foi adequado para estimar o escoamento superficial nas áreas de cerrado, solo exposto (grupo hidrológico do solo A), pastagem e milheto. Portanto, nesses casos o uso do CN é inadequado e o escoamento superficial é melhor estimado a partir da equação Q = CP, onde C é o coeficiente de escoamento superficial. O balanço hídrico a partir de dados de sensoriamento remoto para todo o Cerrado Brasileiro indica que a principal fonte de incerteza na estimativa do escoamento superficial ocorre nos dados de precipitação do TRMM. A variação de água na superfície terrestre calculada como o residual da equação do balanço hídrico usando dados de sensoriamento remoto (TRMM e MOD16) e valores observados de vazão mostram uma correlação significativa com os valores de variação de água na superfície terrestre provenientes dos dados do GRACE. Os dados do GRACE podem representar satisfatoriamente a variação de água na superfície terrestre para extensas regiões do Cerrado. A média anual de perda de solo nas parcelas de solo exposto e cerrado foram de 15.25 t ha-1 yr-1 and 0.17 t ha-1 yr-1, respectivamente. O fator uso e manejo do solo (fator C) da Universal Soil Loss Equation para o cerrado foi de 0.013. Os resultados mostraram que o escoamento superficial, erosão do solo e o fator C na área de cerrado variam de acordo com as estações. Os maiores valores do fator C foram encontrados no verão e outono. Os resultados encontrados nesta tese de doutorado fornecem valores de referência sobre os componentes do balanço hídrico e erosão do solo no Cerrado, que podem ser úteis para avaliar o uso e cobertura do solo atual e futuro. Além disso, conclui-se que os dados de sensoriamento remoto apresentam resultados satisfatórios para avaliar os componentes do balanço hídrico no Cerrado, identificar os períodos de seca e avaliar as alterações no balanço hídrico devido à mudanças de uso e cobertura do solo.
246

The role of plastic mulch as a water conservation practice for desert oasis communities of Northern China

Ingman, Mark Christian 14 September 2012 (has links)
China's Minqin Oasis once welcomed traders along the ancient Silk Road with rivers, lakes, and lush forests, yet today the region's farmland and grassland are increasingly being engulfed by the sands of the Gobi Desert. The severity of this incremental catastrophe for a declining population of 300,000 residents has brought forth a host of recent water policies to include agronomic water conservation through plastic mulch use, computerized regulation and pricing of groundwater, and water diversions from the Yellow River. This study uses a multi-disciplinary and mixed methods approach to better understand farmer perspectives on why they implement certain water and land use practices in agriculture. The world's farmers currently use the majority of the world's available freshwater and arable land. Modern agriculture and its continued intensification also lead to increases in petroleum based inputs such as agrochemicals and agricultural plastics (plasticulture). Despite the large of impact of the decisions made by the world's farmers on natural resources, little research to date has sought to better understand farmers' perceptions and decision-making processes. Plastic film mulch is a technology that has existed since the 1940's and it has been used in places such as rural China for over five decades. This technology conserves a considerable amount of irrigation water and it increases harvests, however, use of plastic for mulch causes waste disposal problems and is an expenditure of petroleum through plastic manufacturing. Without a fundamental understanding of why farmers perceive plastic mulch to be valuable to their households and communities, we may not fully grasp why its global application continues to increase year after year. Moreover, a focused study of plastic mulch use at the local level may also allow researchers and entrepreneurs to develop a suitable alternative mulch that does not consume non-renewable resources or result in detrimental plastic waste after its utility has been exhausted. This study uses household level interviews, surveys, and participant observation to better understand why Minqin County farmers in rural China continue to use plastic mulch and how it may influence their standard of living. / Graduation date: 2013
247

Mulching Techniques for Arid Lands Vegetable Production

Peebles, R. W., Oebker, Norman F. 23 April 1971 (has links)
From the Proceedings of the 1971 Meetings of the Arizona Section - American Water Resources Assn. and the Hydrology Section - Arizona Academy of Science - April 22-23, 1971, Tempe, Arizona / Mulches have been used for evaporation suppression in facilitating vegetable production under arid lands conditions. A study was undertaken in order to evaluate the effectiveness of plastic aprons, supplied by the FAO, as compared to gravel mulches. The vinyl aprons were 6 mils thick and about 1 meter square. Squash plants (Cucurbita pepo) were planted with gravel or plastic aprons or in bare areas and under different watering schedules. The yields under plastic aprons were considerably greater than under gravel and required slightly less water. Bare soil yields lagged far behind. Soil temperatures under the plastic aprons were consistently higher over 24 hours than bare soil, which within limits, would facilitate faster crop growth. Additionally, the apron collects and diverts rainfall to the plant. The vinyl used lasts only 2 seasons, and gravel would probably be a more suitable mulch for developing countries where capital is scarce.
248

Use and Abuse of Southwestern Rivers: Historic Man - The Spaniard

Polzer, Charles W. 23 April 1971 (has links)
From the Proceedings of the 1971 Meetings of the Arizona Section - American Water Resources Assn. and the Hydrology Section - Arizona Academy of Science - April 22-23, 1971, Tempe, Arizona / The early Spanish explorers did not lean toward rivers and boats. Bred in the culture of an arid land, they naturally explored with horses or by foot, leaving boats and rafts to the English and French. No historical records reveal any Spanish desires or attempts to control river flow or harness desert water resources on any appreciable scale. Yet they transformed the Sonoran desert into a productive garden land never before achieved by indigenous peoples. Pueblos were built on river banks where alluvial fans could be easily irrigated. Small arroyo check dams diverted water into wells and town tanks, while larger diversion dams were built to draw water into canals for crop irrigation. The dams were designedly weak and efficient only to the point of diverting sufficient water for the pueblo. There is no concept of storing water in reservoirs or lakes for periods of scarcity, but only of tapping enough water during periods of excess flow. All surplus water was allowed to flow downstream for the use of others in their struggle for survival. In this way the Spanish achieved a balance between human needs and the limited resources of the desert. The records of the Mexicans and the Anglos have been much more exploitive and destructive.
249

Residual Waxes for Water Harvesting

Fink, Dwayne H. 16 April 1977 (has links)
From the Proceedings of the 1977 Meetings of the Arizona Section - American Water Resources Assn. and the Hydrology Section - Arizona Academy of Science - April 15-16, 1977, Las Vegas, Nevada / This study was undertaken to compare the water harvesting potential of several residual waxes with that of refined paraffin. These residual waxes could possibly have advantages over refined paraffin as a soil treatment for water-harvesting catchments in that they are byproducts rather than an end product (constituting an energy savings), are slightly cheaper, and are more adhesive and less brittle. However, these residual waxes have high physical - chemical property variability which complicates testing for utility in water-harvesting. The lack of an easily obtainable ' characterization index ' is a particular deficiency. Upon laboratory testing, several of the residual waxes were found to be superior to refined paraffin in water-repellancy, structural stability, erosion and freeze-thaw resistance and ozone and ultraviolet radiation effects. The need for further laboratory and field testing was noted.
250

Perceptions of water scarcity: the case of Genadendal and outstations.

Noemdoe, Simone Beatrice January 2006 (has links)
<p>The water resources management regime has shifted from one focusing almost exclusively on augmenting supply to one where ensuring access, equity and sustainability are an integral part of the process. A growing demand for water and the fact that the amount of fresh water is constant raises the impression of water scarcity will occur. Indications are that the notion of access to water for basic needs as well as access to productive water underpins perceptions of scarcity. This thesis interrogated perceptions of scarcity in a small rural community in order to understand the role water can play in developing sustainable livelihoods.</p>

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