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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

Water supply in hard rock coastal regions : The effect of heterogeneity and kinematic porosity

Earon, Robert January 2014 (has links)
Water resources in hard rock terrain are difficult to characterize due to heterogeneity and anisotropy in the fracture network, low porosities and limited recharge volumes available during the summer season. Three methods were developed and evaluated in order to assist in water supply planning. A groundwater resources potential index was estimated using multivariate statistics, where physical and geological variables were classified using Analysis of Variance and Fisher's Least Significant Difference tests according to their effect on hydraulic properties. Principal component analysis was used to assign weights to the different classed variables. Classes and weights were used to produce an index referred to as groundwater resources potential (GRP), which correlated significantly with well data. Nearly 80% of the wells with less than median specific capacity values also had GRP values at those locations of zero or lower. Non-stationary variance was observed in specific capacity sub-samples taken from the Geological Survey of Sweden's well archive, despite homogeneous geology and topography. Spatial statistical analyses showed that spatial correlations were weak in well archive samples, implying that regional approximations based on sparse point data are highly error prone. Kinematic porosity estimated using superficial fracture measurements correlated significantly with well archive data. However, low correlation coefficients indicated that well data is likely not a suitable method for predicting water supply characteristics. This approach is an efficient method which shows promise in preliminary estimations of groundwater storage in heterogenic terrains. A groundwater balance model which describes seasonal groundwater storage changes was created in order to better approximate the groundwater situation often found in Swedish urbanized and semi-urbanized hard rock terrains. The model was based on a water budget approach at the pixel scale, and allows for approximation of well extraction which is not uniformly distributed in space. The model showed that in specific regions groundwater extraction may lead to severe decreases in groundwater level, where these impacts may not otherwise be expected. Dry season modelling with 10% increased evapotranspiration showed that in several areas groundwater reservoir depletion may be influenced by more than 50%. / <p>QC 20140331</p>
2

Grundvattenbalans i Kustnära Områden

Hildingsson, Hugo January 2018 (has links)
Vatten är en livsviktig resurs för allt liv. I Sverige kommer hälften av allt dricksvatten från grundvatten. I kustnära områden begränsas grundvattentillgången av omgivningens lagringsförmåga och begränsad tillrinningsyta och det leder till att tillgången på vatten ett växande problem. Det är därför viktigt att förstå alla parametrar som påverkar grundvattnet, både för nutida och framtida brukare. Förändringen av grundvatten i geologiskt blandad miljö är svårt att kartlägga på grund av lagerföljder, materialens heterogenitet, låg kinematisk porositet och okunskap om strömningen mellan olika lager. Grundvattennivåerna skiftar dessutom med klimatet, både över året och över längre tid. Även människans påverkan är av stor betydelse. Rapportens syfte är att se hur dessa parametrar påverkar grundvattenytan i förhållande till varandra. För att undersöka dessa parametrar har tre olika geografiska, kustnära områden jämförts: Stor, Blidö, och Insjön, Rådmansö, i Norrtälje kommun samt Klintemåla i Oskarshamns kommun. För att sätta vattenanvändningen i ett sammanhang har uppgifterna relaterats till vattenexploateringsindexet (WEI). Uppgifter har hämtats från SGU, SMHI och Lantmäteriets arkiv. I två fall har kompletterande fältundersökningar genomförts. Informationen har bearbetats i Excel och programmet GWBal. I dessa områden råder lokal akut eller total vattenbrist under vissa sommarmånader. Förekomsten av vatten är en fråga om lokal tillgång och en generellt god situation i Sverige döljer stora regionala och lokala obalanser. Vad fritidsboende gör spelar större roll än permanentboende då det är under sommarsäsongen problemen är störst. Mindre reservoarer är känsligare när parametrar för klimat, vattenförbrukning och kemisk sammansättning förändras. De klimattendenser som nu uppvisas leder till konklusionen att grundvattentillgången i områdena under den kritiska perioden kommer att minska. / Water is a vital resource for all human life. Half of all drinking water in Sweden comes from groundwater and in some coastal areas, the access to water is a growing problem. It is therefore crucial to properly understand all parameters that affect the access to water, both for present and future users. The change in groundwater level in geologically varied environments is hard to get a complete picture of. Stratification, heterogeneity of soil and rock, low kinematic porosity and flow between the layers are partially unknown parameters and therefore highly uncertain. Groundwater levels also change with the climate, both over the year and over longer period of time. The impact of humans is of great importance. The objective is to see how these parameters effects groundwater level in relation to each other. To analyze these factors, three different geographic areas in Sweden will be compared: Stor, Blidö, and Insjön, Rådmansö, in Norrtälje kommun and Klintemåla in Oskarshamns kommun. To put the water use and potential stress in context, the results will be related to the Water Exploitation Index (WEI). Data was obtained from the archives of SGU, SMHI and Lantmäteriet. In two cases, the information was supplemented with field investigation. The information was processed in Excel and the program GWBal. Overall, the local shortage of water in these areas is urgent during some summer months. The water supply is a local resource and the generally good situation in Sweden conceals major regional and local imbalances. The part time residents have a much greater impact since the problem is at its peak during summer. Changes in the climate, withdrawal of water and chemical composition have greater impact on small reservoirs then on big ones. With today’s trend in climate, the conclusion is that the availability of groundwater in the areas will decrease.
3

Water Supply Planning for Landscape Irrigation in Virginia

Tucker, Adrienne Janel LaBranche 10 June 2009 (has links)
A water supply plan approach was used to investigate irrigation application on landscaped areas in Virginia with a focus on turfgrass. The economically-important turfgrass industry in Virginia should be proactive in conserving drinking water supplies to meet human consumption needs, especially in drought times. This thesis investigates current irrigation water supplies, water supply sustainability, and alternative water sources to meet irrigation demands and offers an insight on how potable water is unnecessarily consumed for non-potable irrigation needs. A Virginia evapotranspiration website was developed to offer a scientifically based source for efficient irrigation scheduling. The website was developed using a collaborative and user-centered design method, which included potential users in the process. The final website is hosted on the Virginia Tech website at http://www.turf.cses.vt.edu/Ervin/et_display.html and utilizes data from weather stations throughout the state. Evapotranspiration-based irrigation was tested at three case study sites in Blacksburg, Williamsburg and Norfolk, Virginia to assess potential water conservation. In Williamsburg, a 55% water savings was reported with evapotranspiration-based irrigation. In Blacksburg, slightly more water was applied on research greens irrigated based on evapotranspiration demand. Significantly less water was applied in Norfolk, compared to the evapotranspirationbased irrigated plots. The study also uncovered increased confidence to alter irrigation systems and the need to conduct irrigation audits when irrigating based on evapotranspiration. Evapotranspiration-based irrigation, reclaimed water and harvested rainwater were investigated to determine feasibility for meeting irrigation demands, while reducing potable water consumption at four case study sites in Blacksburg, Fairfax, Williamsburg and Norfolk, Virginia. Due to the limited collection potential at the Blacksburg site, reclaimed water and harvested rainwater was not feasible. However, the on-site weatherstation could offer a unique opportunity to calculate evapotranspiration. In Fairfax, all three alternative water sources could be integrated to supply enough water to irrigate a soccer field and adjacent athletic fields and save an estimated $7,000 per season in potable water costs. Harvested rainwater at the Williamsburg site could supplement the irrigation pond and reduce reliance on groundwater. In Norfolk, reclaimed water use is economically feasible, but rainwater harvesting could meet the irrigation needs, while evapotranspiration-based irrigation is too labor intensive for homeowners. / Ph. D.
4

Beyond the Aquifer : planning for San Antonio's future water supply

Laughlin, Nathan Daniel 24 November 2010 (has links)
This report examines water supply planning issues in San Antonio, Texas. San Antonio is unique among large cities in the United States in that it relies almost exclusively on a single source, the Edwards Aquifer, for its water supply. Because San Antonio’s water demand is projected to outgrow the Aquifer’s capacity, the city must consider other options to extend and augment its current water supply. After describing the hydrogeology and water supply history of San Antonio, this report explains the multitiered water planning structure and current and future water needs for the city. It then studies and evaluates three short-to-mid term water supply options. By continuing to develop its already successful water conservation programs and water reclamation system, San Antonio can delay the need for more costly and environmentally impactful water supply options down the road, and wisely manage the resources it already draws from. / text
5

Hierarquização de ações pré avaliatórias para o gerenciamento dos sistemas de abastecimento de água / Hierarchy of pre evaluative actions for the management of water supply systems

Manca, Ricardo da Silva, 1977- 22 January 2015 (has links)
Orientadores: José Gilberto Dalfré Filho, Antonio Carlos Zuffo / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Civil, Arquitetura e Urbanismo / Made available in DSpace on 2018-08-27T05:15:29Z (GMT). No. of bitstreams: 1 Manca_RicardodaSilva_D.pdf: 9827173 bytes, checksum: 450008bf7cf24543fd46e355c0e9e892 (MD5) Previous issue date: 2015 / Resumo: A discussão acerca do gerenciamento dos recursos hídricos torna-se mais complexa e importante à medida que ocorre a integração entre todas as medidas cabíveis, tanto na oferta quanto na demanda, que permitem o uso eficiente da água. No entanto, ainda há um longo caminho a percorrer para assegurar a distribuição eficiente e equitativa da água. Se os planos voltados à distribuição de água buscavam somente novas captações, atualmente, precisam incorporar novas ferramentas de gestão, tais como a redução das perdas de água, o reúso, o racionamento, a bonificação e tarifação, as campanhas de incentivo à redução do consumo. Mesmo que todas as alternativas do gerenciamento da demanda sejam importantes, é preciso que se definam quais as ações que realmente podem ser valoradas e mensuradas de acordo com a responsabilidade do gestor do sistema, ou seja, há uma enorme dificuldade em se ponderar opções que poderiam contribuir com o aumento da disponibilidade de água de uma região, mas que dependem de fatores externos não controláveis, como fatores climáticos e conscientização da sociedade. Nesse sentido, o objetivo desta pesquisa foi identificar e hierarquizar as principais ações de atuação na demanda hídrica que podem contribuir para o aumento da disponibilidade de água da Região Metropolitana de São Paulo. Fazendo uso do método de tomada de decisão Delphi e das metodologias multicriteriais AHP, CP e CGT, a avaliação dos resultados mostra que medidas como o reúso e a redução de perdas são aliados importantes e que podem contribuir para a diminuição da escassez hídrica nesta região. Dessa forma, conhecendo-se as duas principais medidas prioritárias para a Região Metropolitana de São Paulo, o trabalho propõe a criação do Gerenciamento Integrado da Demanda de Água Prioritário (GIDAP), que avalia todas as medidas no estudo da demanda, porém, com valoração maior para o reúso e a redução de perdas de água / Abstract: The discussion about the management of water resources becomes more complex and important as the integration occurs between all appropriate measures, both supply and demand, which allow the efficient use of water. However, there is still a long way to go to ensure the efficient and equitable distribution of water. If the trend of the traditional planning of water distribution is only the search for new funding nowadays it is necessary to incorporate new management tools, such as the reduction of water losses, reuse, rationing, the subsidy and pricing, incentive campaigns to reduction of consumption. Even if all the demand management alternatives are important, it is necessary to define what actions can actually be valued and measured in accordance with the system manager's responsibility, ie, there is a huge difficulty in considering options that could contribute to the increased availability of water in a region, but that depend on uncontrollable external factors such as climatic factors and awareness of society. In this sense, the objective of this research was to identify and prioritize the key working actions in water demand that may contribute to the increased availability of water in the Metropolitan Region of São Paulo. Making use of the decision-making method Delphi and multicriteria methodologies AHP, CP and CGT, the evaluation of the results shows that measures such as the reuse and waste reduction are important allies and that can contribute to the reduction of water scarcity in the region. Thus, knowing the two main priorities for the Metropolitan Region of São Paulo, the paper proposes the creation of the Integrated Management of Water Demand Priority (GIDAP), which assesses all the measures on the demand study, however, with valuation highest to reuse and reduction of water losses / Doutorado / Recursos Hidricos, Energeticos e Ambientais / Doutor em Engenharia Civil

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