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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.
1

Evaluation of the water quality of Lake Nsezi in Richards Bay

Cimanga, Lukusa 04 1900 (has links)
Freshwater of acceptable quality is crucial for certain needs and uses such as recreational, domestic and industrial activities (Bartram and Balance, 1996). Water contamination and excessive use and abuse of the fresh water environment, threaten development as well as a variety of other life aspects and make water assessment necessary for safe drinking water delivery. It has been proven that water of good quality is important to sustain development (Karolina et al., 2011). South African freshwater resources such as lakes, rivers and groundwater, undergo intense stress owing to a rapidly expanding population, a growing economy, severe pollution from various industries, a possible effect of global warming and an increase in droughts (Oberholster et al., 2008). A study done by Boyd (2010), further confirmed the decline in water quality of these resources due to excessive contamination caused by urban development, human activities, industrialisation, forest establishment, agriculture and mining operations. For this project, the analysis of physical, chemical and biological parameters of the water from Lake Nsezi was used to assess the water quality of the lake. Results from the analysis were compared to Target Water Quality Range (TWQR) of the Water Quality Guidelines for the Aquatic Environment (WQG/AE) and for Domestic Use (WQG/DU). A further comparison was done between data from the current study and available historical water quality data of Lake Nsezi. From the results for this project and historical data, it was evident that parameters such as total dissolved solids (TDS) and chloride, metals such as aluminium, cadmium, copper, lead and manganese, and total coliform counts were above the TWQR for the WQG/AE and WQG/DU at most of the sampling sites. / Environmental Sciences / M. Sc. (Environmental Science)
2

Managing Regional Water Resources Amidst Rapid Urbanization in Southwest Florida: A Case Study

Caesar, Nicole Owusua 11 July 2014 (has links)
Experts and organizations involved in freshwater resources management have emphasized the importance of long-term urban resource planning and management that considers the tight coupling which exists between human - nature - technology systems. The resistance of contemporary urban growth efforts to consider resource carrying capacities and ecosystem requirements has led to costly unintended consequences including the deterioration of natural capital and their associated ecosystem services, and the degradation of water resource flows. As these problems continue to worsen, resource experts have called for the development of a new water resource management paradigm inclusive of various sustainability criteria. Historically water-rich Florida has demonstrated increased resource strain over the past four decades, in spite of the creation of some of the nation's most comprehensive water resource and growth management legislation. The Southwest Florida Water Management District was originally created to manage regional flooding in 1961 and has undergone a tremendous expansion in statutorily mandated resource responsibilities over the past 40 years. This case study utilized semi-structured surveys of current and former agency employees to examine the agency's expansion into integrated water resource management amidst rapid regional urbanization.
3

Gouvernance des eaux douces dans les territoires méditerranéens : vers une norme commune / Governance of freshwater in the mediterranean area : towards a common norm

Zhou, Xin 15 December 2014 (has links)
L'eau douce est devenue un sujet de préoccupation majeur depuis la fin du XXe siècle, tant au niveau international qu'au niveau national. L'eau douce est une ressource rare et inégalement répartie dans la région méditerranéenne. La surexploitation des eaux de surface et des eaux souterraines ainsi que la dégradation de la qualité de l'eau sont également deux problèmes urgents pour cette région. Les pays méditerranéens ainsi que la communauté internationale se sont engagés dans la recherche d'une meilleure gestion de l'eau douce. Nombre d'études, de programmes et de coopérations internationales sont là pour en témoigner. Nous avons constaté que les engagements nationaux et internationaux existants ne répondaient que partiellement à ces problèmes urgents relatifs à l'eau douce. En tenant compte des situations particulières de la région, nous avons développé les perspectives d'une norme commune sur l'eau douce pour la région méditerranéenne. / Fresh water has become a major concern since the late twentieth century in both international and national level. Fresh water resources are scarce and spread unequally in the Mediterranean region. Overexploitation of surface water and groundwater, as well as degradation of water quality are two pressing issues for this region. Mediterranean countries and the international community have engaged in the search for a better management of fresh water. Lots of studies, programs and international cooperations are there to prove this. We found that the existing national and international undertake only partially these urgent problems related to freshwater. Taking account the particular circumstances of the region, we have developed the prospects for a common norm for fresh water to the Mediterranean region.
4

Evaluating the potential of artificial infiltration to increase groundwater storage using MIKE SHE : A case study in northern Storsudret, Gotland / Utvärdering av konstgjord grundvatteninfiltration för ökad grundvattentillgång med hjälp av MIKE SHE : En fallstudie i norra Storsudret, Gotland

Schmidt, Sara, Uppsäll, Per January 2020 (has links)
The island of Gotland, Sweden, is struggling with supplying the population with freshwater during summers. At the same time as the demand increases during these months, the warm weather and geological conditions prevent sufficient volumes of groundwater to recharge. The Swedish Environmental Research Institute is conducting a research project together with Region Gotland, aiming to solve the freshwater supply problem in Storsudret, located on southern Gotland, by investigating the suitability of different water management techniques. In this thesis, the impacts of artificial infiltration on the groundwater level have been investigated in northern Storsudret, where a sandy deposit has been identified to possibly be suitable for increased groundwater storage. The modelling software MIKE SHE was used to create a groundwater model to assess the suitability of the area. Further, an assessment of using MIKE SHE for this purpose was done. Electrical resistivity measurements and Ground Penetrating Radar were used in field, to identify the geological conditions and conceptualize the domain. The model was based on the field data, as well as data from e.g. SMHI, Lantmäteriet and SGU. Based on the model simulations, locations were evaluated to find suitable areas for artificial infiltration during spring, and for groundwater extraction during summer. The results indicate that the sand deposit present in the domain is thin, leading to high evapotranspiration during spring and summer. Artificial infiltration elevates the groundwater level in a limited proximity to the infiltration point. However, the difference in groundwater level decreased during July and the conditions were the same as without artificial infiltration in August. Maximal water extraction during June, July, and August, did not seem to impact surrounding groundwater levels significantly. This suggests that the combination of low hydraulic conductivity and inadequate thickness of the sand limits the possibilities to use the deposit as an aquifer. MIKE SHE was assessed to perform well, when comparing the water balance with historic data. It was evaluated to be suitable for projects of this character, but limited research and documentation on artificial infiltration in MIKE SHE was found. However, to validate the groundwater flow simulation, sufficient groundwater observation data is required. / Under sommarhalvåret är Gotland ett populärt turistmål och trycket på infrastrukturen ökar kraftigt, särskilt färskvattenresurserna belastas tungt. Klimatförändringar och geologiska förutsättningar leder till förändringar i grundvattenbildningen och försvårar vattenhållningen ytterligare. Svenska Miljöinstitutet har tillsammans med bland annat Region Gotland påbörjat ”Testbädd Storsudret” som en satsning för att hitta lösningar på vattenproblemen. Ett område med större sandmäktighet, och möjligheter för ökad vattenlagring genom konstgjord infiltration, har identifierats som en potentiell kandidat för att stärka vattenförsörjningen på Storsudret, södra Gotland. I detta arbete undersöks dessa möjligheter genom geofysiska mätningar och modellering med programvaran MIKE SHE. För att närmare undersöka de geologiska förhållandena i området utfördes mätningar med både elektrisk resistivitet och markradar. Modellen baserades både på dessa fältmätningar och data från bland annat SMHI, Lantmäteriet och SGU samt litteratur. Områdets generella lämplighet samt lämplig lokalisering av platser för infiltration och grundvattenbrunnar undersöktes med hjälp av den konstruerade modellen. Resultatet pekar tydligt på att sandmäktigheten i området är för liten för att det ska vara lämpligt för ändamålet. Vid konstgjord infiltration dräneras mycket av vattnet till dikena och bort från området, men även evapotranspirationen ser ut att minska grundvattenbildningen kraftigt. Den konstgjorda infiltrationen verkar endast påverka grundvattennivåerna i närheten av infiltrationspunkten och effekterna av infiltrationen ser ut att avta och inga spår av infiltrationen är synliga två månader efter dess slut. Grundvattennivåer runt brunnarna verkade inte påverkas markant vid högsta möjliga pumphastighet. Vilket kan tyda på att den hydrauliska konduktiviteten i kombination med sandens begränsade mäktighet är de faktorer som i huvudsak begränsar uttag av grundvatten. MIKE SHE bedöms vara användbart för projekt av liknande karaktär som detta även om dokumentation gällande konstgjord infiltration ansågs bristfällig. För att kunna validera, och kalibrera, en modell behövs däremot tillräckligt med grundvattenobservationer.
5

Considering water quality and characterizing water as a resource in Life Cycle Assessment / Considération de la qualité de l'eau et caractérisation de l'eau en tant que ressource en Analyse du Cycle de Vie

Pradinaud, Charlotte 25 April 2018 (has links)
Maintenir la qualité des ressources en eau est l'un des défis majeurs auxquels la société d’aujourd’hui doit faire face. Il est donc primordial que ce critère soit intégré correctement dans les méthodes d’analyse d’impacts environnementaux, tel que l’Analyse du Cycle de Vie (ACV). Cependant, l’estimation de la qualité de l’eau et la manière dont cette information est utilisée dans les modèles d’évaluation d’impacts soulève un certain nombre de challenges méthodologiques, d’où la problématique de recherche : « Comment considérer la qualité de l’eau dans l’évaluation des impacts de l’utilisation de l’eau en ACV, de l’inventaire aux Aires de Protection ? ». Ce travail de thèse propose dans un premier temps une étude approfondie du rôle et de la nécessité de l’information « qualité de l’eau » dans l’évaluation des impacts de plusieurs type d’utilisation d’eau (usage consommatif, dégradatif et amélioration de la qualité). Cette étude s’applique aux différentes chaines de causalité de manière mécanistique, jusqu’aux trois Aires de Protection (AoP) santé humaine, qualité des écosystèmes et ressources naturelles. Afin d’améliorer la compréhension et la considération des impacts de l’utilisation de l’eau sur l’AoP ressources naturelles, un cadre théorique consensuel élaboré en collaboration avec WULCA (le groupe Water Use in LCA, de l’UNEP-SETAC Life Cycle Initiative) est défini. Ce cadre fournit une base solide pour l’élaboration cohérente de méthodes d’analyse d’impacts, permettant d’évaluer la diminution irréversible de la disponibilité physique de l'eau douce et/ou de son degré d'utilisabilité pour les générations futures. La thèse se conclut par le développement d’un modèle de caractérisation d’impacts de la dégradation des ressources en eau causée par des émissions. Des facteurs de caractérisation sont calculés pour cinq métaux, au niveau midpoint. L’application de ces indicateurs permet d’améliorer l’interprétabilité des résultats concernant les défis futurs liés aux ressources en eau ainsi que les résultats des impacts sur la santé humaine liés aux problèmes de qualité d’eau / Maintaining the quality of water resources is one of the major challenges society faces today. It is therefore essential that this criterion be properly integrated into environmental impact assessment methods, such as Life Cycle Assessment (LCA). However, the estimation of water quality and how this information is used in impact assessment models raises a number of methodological challenges; hence, the general research question is “How to consider water quality in water use impact assessment in LCA, from inventory to Areas of Protection?” This thesis first provides a detailed study about the role and necessity of "water quality" information in assessing impacts of different types of water use (consumptive and degradative use, as well as quality improvement). This study applies to the different cause-effect chains in a mechanistic way, in view of the three Areas of Protection (AoP) human health, ecosystem quality and natural resources. In order to improve the understanding and consideration of the water use impacts on the AoP natural resources, a consensual framework, developed jointly with WULCA (Water Use in LCA group of the UNEP-SETAC Life Cycle Initiative), is presented. This framework provides a solid basis for the consistent development of impact characterization models to assess the irreversible reduction in physical availability of freshwater and its quality-based usability for future generations. The thesis ends with the development of a characterization model for water resource degradation impacts caused by emissions. Characterization factors are calculated for five metals at the midpoint level. The application of these indicators improves the interpretability of LCA results regarding future water resource challenges and water-quality related impacts on human health.
6

Assessing water quality status by means of the Driver-Pressure-State-Impact-Response (DPSIR) model around Mapungubwe National Park, Limpopo Province, South Africa

Mathetsa, Steven Matome 12 1900 (has links)
Freshwater resources play an important role in the integrity of natural ecosystems as well as livelihoods of communities. However, South Africa has limited freshwater resources and many of this country’s inland water streams are polluted as a result of human activities. Various legislations such as the National Water Act (Act No. 36 of 1998) were promulgated in order to address the issue of sustainable management of these resources. In this study, the Driver-Pressure-State-Impact-Response (DPSIR) model was applied to determine water quality challenges and threats in and around the Mapungubwe National Park and Heritage Site (MNPHS). This study area was declared as a heritage site by the United Nations Educational, Scientific and Cultural Organisation (UNESCO) and is also a national park. Several research objectives were formulated and various methodologies were used to address the research aim. In determining land uses around the study area, site visits, visual inspections, literature reviews as well as the analysis of the national land use data were undertaken. Various land uses that have potential to negatively impact water quality were identified. In order to determine the status of water quality in the study area, water samples were analysed in-situ and in the laboratory. The results obtained showed that water quality was generally compliant with a few exceptions. For example, the concentrations of nitrates, microbes, and few metals such as mercury and beryllium were not complying with water quality guidelines and standards. Finally, in formulating the DPSIR framework for the MNPHS, a participatory approach was used where stakeholders were interviewed by means of a questionnaire. One of the most salient finding of the DPSIR modelling in this study was institutional weaknesses associated with the poor implementation of existing water related laws and regulations. The study also highlighted a few recommendations for further action and research. / Environmental Sciences / M.Sc. (Environmental Management)
7

L’irrigation dans le bassin du Rhône : gestion de l’information géographique sur les ressources en eau et leurs usages / Irrigation in the Rhône basin : geographic information system about freshwater resources and water uses

Richard-Schott, Florence 06 December 2010 (has links)
L’irrigation a connu de grands changements dans le bassin du Rhône français durant les trente dernières années du vingtième siècle. La mise en œuvre d’un Système d’Information sur le bassin du Rhône (SIR) montre l’existence de quatre grands systèmes d’irrigation qui s’individualisent au sein de plusieurs « régions d’irrigation ». Ces dernières révèlent des dynamiques contrastées, mettant à mal l’idée que l’irrigation aurait connu une expansion continue et homogène, même si les superficies irriguées augmentent globalement. Ces dynamiques spatiales s’expliquent par les profondes transformations d’une pratique modernisée, utilisant des techniques toujours plus économes en eau. C’est d’ailleurs le deuxième enseignement de la recherche : l’accroissement général des superficies irriguées n’a pas entraîné une augmentation des demandes en eau. Celles-ci ont plutôt tendance à diminuer, de l’ordre de 30 % en trente ans. Sous l’impulsion des gestionnaires, les irrigants font un usage de plus en plus raisonné des ressources en eau et, à terme, il ne faut certainement pas considérer l’irrigation comme une menace généralisée pour les équilibres environnementaux... Le mémoire de thèse s’accompagne d’un système de gestion de l’information géographique et d’un atlas en version électronique. / Over the last thirty years of the twentieth century, irrigation in the French basin of the Rhône river has undergone substantial change. The implementation of a Geographic Information System on the Rhône basin (SIR) demonstrates the existence of four main irrigation systems individualized within several “irrigation regions.” These reveal in turn a series of contrasted dynamics, putting into question the idea that irrigation expansion had been both continuous and homogeneous, even though the total surface area irrigated actually increased. These spatial dynamics can be accounted for by the deep transformations due to a modernised practice that relies on techniques ever more sparing with water. This is in fact the second lesson one can draw from this study : the general increase in irrigated surface areas did not lead to an increase in water demand. On the contrary, water demand has tended to diminish, in the order of 30% over thirty years. Driven by management, the cultivators’ use of water resources is more and more reasoned, so that in the long run irrigation is surely no global threat to environmental balance. The thesis includes a system for managing geographic information as well as an electronic atlas.

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