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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.
31

Water harvesting through ponds in the Arco Seco region of the Republic of Panama : decision support system for pond storage capacity estimation

Desrochers, Anne January 2004 (has links)
The 'Arco Seco' or 'Dry Arc' region of the Republic of Panama is considered to be the driest in the country, where many areas of this region experience severe water stress during the months of January through May. This study was conducted to develop a tool for the assessment of sustainable implementation of water harvesting through ponds for agricultural purposes in the region. A computer based Decision Support System (DSS) has been developed specifically for the Arco Seco region in order to facilitate pond storage capacity estimation. As part of the DSS, four computer programs have been designed for four different case scenarios; the first one is for sites that have high water demand and no topographical restrictions for pond size; the second is for fairly high water demand, no topographical restrictions for pond size, and for farmers who wish to have a backup of water to use mostly during drier years; the third is for low water demand, usage during the dry season only, and topographical restrictions for pond size, and finally the fourth is for constant water demand throughout the year, and for sites where runoff is the only water source.* / *This dissertation is a compound document (contains both a paper copy and a CD as part of the dissertation).
32

Art and the greater good : ecology and the leisure economy : a thesis presented in partial fulfillment of the requirements for the degree of Masters in Fine Arts at Massey University, Wellington, New Zealand

Wallis, Samantha January 2010 (has links)
Art and the Greater Good: Ecology and the Leisure Economy is a research project concerned with exploring how one could alternatively address the environmental issues of our day through site-specific art. Central to this investigation has been attending to the ways historical and contemporary accounts of environment politics, site specificity, land and environmental art could resonate within a more modest artistic gesture. The resulting work Would you go on without me? reflects the possibility of this by its position in an indeterminate zone; that draws together the demotic, gardening, rainwater harvesting, play and ecology into the manifold of environmental art.
33

Hydrological impacts of land use changes on water resources management and socio-economic development of upper Ewaso Ng'iro River Basin in Kenya

Ngigi, Stephen. January 1900 (has links)
Thesis (doctoral)--Delft University and UNESCO-IHE Institute for Water Education, 2006. / Includes bibliographical references (p. 121-129).
34

Rainwater harvesting systems and their influences on field scale soil hydraulic properties, water fluxes and crop production /

Kosgei, Job Rotich. January 2009 (has links)
Thesis (Ph.D.) - University of KwaZulu-Natal, Pietermaritzburg, 2009. / Full text also available online. Scroll down for electronic link.
35

A bacia do Rio Capivara, manancial de abastecimento do município de São João, PR: percepção de moradores

Rodrigues, Marilucia Cyrino 25 April 2014 (has links)
A análise da percepção ambiental dos moradores da bacia do manancial de abastecimento mostrou que a maioria desses entrevistados possui sentimento de corresponsabilidade com essa condição do rio. A pesquisa foi realizada com moradores da bacia do rio Capivara, manancial de abastecimento do Município de São João, Paraná, com objetivo de analisar a percepção desses sujeitos com relação ao contexto da bacia e seus reflexos na água do rio. Para subsidiar este estudo apropriamo-nos de referenciais teóricos como a percepção ambiental, a Política Nacional de Recursos Hídricos e a Resolução do Conama 357/2005. Os resultados da entrevista semiestruturada aplicada com trinta moradores foi correlacionado com os dados e levantamento cartográfico do uso e ocupação do solo e resultados de análises de água. A condição do rio enquanto manancial de abastecimento da população urbana está presente para todos os sujeitos entrevistados. Neste sentido, a investigação da percepção ambiental dos moradores da microbacia do manancial revelou aspectos importantes da conduta, valores, significados históricos e ações de preservação destes sujeitos diante da condição do rio. A responsabilidade compartilhada entre moradores, poder público, Sanepar e Emater foi defendida pela maioria dos sujeitos como a melhor alternativa para promover ações de manejo e preservação do rio como manancial. / The analysis of environmental perception in the context of the basin of water supply source showed that the majority of interviewed residents has responsibility feelings with this condition of the river. The survey was conducted with residents from the Basin of Capivara River, which is the supply source in São João city, Paraná, in order to examine the perception of these individuals regarding the context of the basin and reflections in the river water. To subsidize this study, it was used the theoretical frameworks, such as the environmental perception, the National Policy on Water Resources and the CONAMA Resolution 357/2005. The results of semi-structured interview with 30 residents were correlated with the data and cartographic survey of the use and occupation of land and water analysis results. The river condition as a supply source of the urban population is present for all interviewees. In this sense, the investigation about inhabitants' environmental perception of the micro-basin of spring revealed important aspects of conduct, values, historical meanings and the preservation actions of these individuals concerning the river condition. The shared responsibility among residents, public power, Sanepar and Emater was advocated by the majority of individuals as the best alternative to promote management actions and preservation of the river as a source.
36

A bacia do Rio Capivara, manancial de abastecimento do município de São João, PR: percepção de moradores

Rodrigues, Marilucia Cyrino 25 April 2014 (has links)
A análise da percepção ambiental dos moradores da bacia do manancial de abastecimento mostrou que a maioria desses entrevistados possui sentimento de corresponsabilidade com essa condição do rio. A pesquisa foi realizada com moradores da bacia do rio Capivara, manancial de abastecimento do Município de São João, Paraná, com objetivo de analisar a percepção desses sujeitos com relação ao contexto da bacia e seus reflexos na água do rio. Para subsidiar este estudo apropriamo-nos de referenciais teóricos como a percepção ambiental, a Política Nacional de Recursos Hídricos e a Resolução do Conama 357/2005. Os resultados da entrevista semiestruturada aplicada com trinta moradores foi correlacionado com os dados e levantamento cartográfico do uso e ocupação do solo e resultados de análises de água. A condição do rio enquanto manancial de abastecimento da população urbana está presente para todos os sujeitos entrevistados. Neste sentido, a investigação da percepção ambiental dos moradores da microbacia do manancial revelou aspectos importantes da conduta, valores, significados históricos e ações de preservação destes sujeitos diante da condição do rio. A responsabilidade compartilhada entre moradores, poder público, Sanepar e Emater foi defendida pela maioria dos sujeitos como a melhor alternativa para promover ações de manejo e preservação do rio como manancial. / The analysis of environmental perception in the context of the basin of water supply source showed that the majority of interviewed residents has responsibility feelings with this condition of the river. The survey was conducted with residents from the Basin of Capivara River, which is the supply source in São João city, Paraná, in order to examine the perception of these individuals regarding the context of the basin and reflections in the river water. To subsidize this study, it was used the theoretical frameworks, such as the environmental perception, the National Policy on Water Resources and the CONAMA Resolution 357/2005. The results of semi-structured interview with 30 residents were correlated with the data and cartographic survey of the use and occupation of land and water analysis results. The river condition as a supply source of the urban population is present for all interviewees. In this sense, the investigation about inhabitants' environmental perception of the micro-basin of spring revealed important aspects of conduct, values, historical meanings and the preservation actions of these individuals concerning the river condition. The shared responsibility among residents, public power, Sanepar and Emater was advocated by the majority of individuals as the best alternative to promote management actions and preservation of the river as a source.
37

Thermally Driven Technologies for Atmospheric Water Capture to Provide Decentralized Drinking Water

January 2020 (has links)
abstract: Limited access to clean water due to natural or municipal disasters, drought, or contaminated wells is driving demand for point-of-use and humanitarian drinking water technologies. Atmospheric water capture (AWC) can provide water off the centralized grid by capturing water vapor in ambient air and condensing it to a liquid. The overarching goal of this dissertation was to define geographic and thermodynamic design boundary conditions for AWC and develop nanotechnology-enabled AWC technologies to produce clean drinking water. Widespread application of AWC is currently limited because water production, energy requirement, best technology, and water quality are not parameterized. I developed a geospatial climatic model for classical passive solar desiccant-driven AWC, where water vapor is adsorbed onto a desiccant bed at night, desorbed by solar heat during the day, and condensed. I concluded passive systems can capture 0.25–8 L/m2/day as a function of material properties and climate, and are limited because they only operate one adsorption-desorption-condensation cycle per day. I developed a thermodynamic model for large-scale AWC systems and concluded that the thermodynamic limit for energy to saturate and condense water vapor can vary up to 2-fold as a function of climate and mode of saturation. Thermodynamic and geospatial models indicate opportunity space to develop AWC technologies for arid regions where solar radiation is abundant. I synthesized photothermal desiccants by optimizing surface loading of carbon black nanoparticles on micron-sized silica gel desiccants (CB-SiO2). Surface temperature of CB-SiO2 increased to 60oC under solar radiation and water vapor desorption rate was 4-fold faster than bare silica. CB-SiO2 could operate >10 AWC cycles per day to produce 2.5 L/m2/day at 40% relative humidity, 3-fold more water than a conventional passive system. Models and bench-scale experiments were paired with pilot-scale experiments operating electrical desiccant and compressor dehumidifiers outdoors in a semi-arid climate to benchmark temporal water production, water quality and energy efficiency. Water quality varied temporally, e.g, dissolved organic carbon concentration was 3 – 12 mg/L in the summer and <1 mg/L in the winter. Collected water from desiccant systems met all Environmental Protection Agency standards, while compressor systems may require further purification for metals and turbidity. / Dissertation/Thesis / Doctoral Dissertation Civil, Environmental and Sustainable Engineering 2020
38

Evaluating rainwater harvesting and conservation techniques on the Towoomba/Arcadia Ecotope

Ngwepe, Mantlo Richard January 2015 (has links)
Thesis (MSc .(Agronomy)) -- University of Limpopo, 2015 / The changes in climate, especially poor rainfall patterns and distributions are key issues posing major agricultural challenges for food security and threaten the rural livelihoods of many communities in the Limpopo Province. Rainfall (P) is low and limited. These limited P is mostly lost through runoff and evaporation, which result in low soil moisture availability and possible crop failure. Therefore, techniques that reduce these water losses are important for improving dryland crop production and rainwater productivity (RWP). The objectives of this study were to determine the potential and effectiveness of rainwater harvesting and conservation techniques (RWH&CT’s) to conserve and improve plant available water (PAW) for dryland maize production and also determine the efficiency of the RWH&CT’s to improve dryland maize yield and RWP compared to conventional tillage (CON). The study was conducted over a period of two growing seasons (2008/09; 2009/10) using maize as indicator crop at the Towoomba Research Station of the Limpopo Department of Agriculture in the Limpopo Province of South Africa, on an Arcadia ecotope. The experiment was laid out in a randomized complete block design, with four replications and five treatments. The five treatments used in the study were; conventional tillage (CON), No-till (NT), In-field rainwater harvesting (IRWH), Mechanized basins (MB) and Daling plough (DAL). The IRWH and DL were classified as rainwater harvesting techniques (RWHT’s), whilst MB and NT were classified as water conservation techniques. Two access tubes were installed at each treatment to measure the soil water content (SWC) at four different soil depths of 150, 450, 750 and 1050 mm using the neutron water meter. The data collected included climatic data, soil and plant parameters. The data were subjected to analysis of variance through NCSS 2000 Statistical System for Windows and GENSTAT 14th edition. Mean separation tests were computed using Fisher's protected least significant difference test. The SWC of IRWH, DAL and MB were about 510 and 490 mm higher compared to CON and NT treatment during the 2008/09 and 2009/10 seasons, respectively. The PAWT of the IRWH, MB and DAL was significantly different from the CON treatment during the 2008/09 season. For both seasons the biomass yield of the IRWH treatment was significantly different from the NT treatment, producing 23 and 50% more biomass in the 2008/09 and 2009/10 growing seasons, respectively. The grain yield under IRWH was significantly different from the NT treatment during both 2008/09 and 2009/10 seasons. The highest maize grain yield of IRWH was achieved during the 2009/10 season with 56% higher grain yield than the NT treatment. RWP from various RWHT’s were significantly different from the NT treatment. These results indicate that IRWH and DAL were 12 and 2% more effective in converting rainwater into harvestable grain yield than the CON treatment. R2 values of 68.6 and 78.4% for SWC and transpiration (Ev) were obtained when correlated with maize grain yield respectively. This indicates the importance of moisture conservation for improved dryland maize production under low P areas. Therefore, the use of appropriate RWHT’s by smallscale farmers maybe crucial to improve dryland maize production. IRWH outperformed all other treatments in terms of the soil parameters and plant parameter measured during the period of this study. Therefore, these results suggest IRWH has potential of sustaining maize yields under low rainfall conditions. Key words: Rainwater harvesting, conservation techniques, ecotope, rainwater productivity, maize yield, precipitation use efficiency.
39

Atmospheric Water Harvesting: An Experimental Study of Viability and the Influence of Surface Geometry, Orientation, and Drainage

Hand, Carson T 01 June 2019 (has links)
Fresh water collection techniques have gained significant attention due to global dwindling of fresh water resources and recent scares such as the 2011-2017 California drought. This project explores the economic viability of actively harvesting water from fog, and techniques to maximize water collection. Vapor compression and thermoelectric cooling based dehumidifier prototypes are tested in a series of experiments to assess water collection capability in foggy environments, and what parameters can increase that capability. This testing shows an approximate maximum collection rate of 1.25 L/kWh for the vapor compression prototype, and 0.32 L/kWh for the thermoelectric cooling prototype; compared to 315 L/kWh for desalination or 12 L/m2/day for passive meshes. Exploration of parameters on the thermoelectric cooling prototype show a potential increase in water collection rate of 29% with the addition of a Teflon coating to the collection surface, 15% by clearing the collection surface, and 89% by tilting certain collection surfaces by 60-75°. In combination, these parameters could push active atmospheric water harvesting into economic viability where significant infrastructure investment is not feasible.
40

Managing water for sustainable Agriculture: The case of Ralegan Siddhi in India.

Deshmukh, Rupali January 2016 (has links)
Water is essential element for human survival but unstainable development practices and short term economic benefits are responsible for water scarcity in many areas around the world. Climate change is aggravating the risk with distribution and water availability. Agriculture is a sector highly dependent on water. The livelihood of a vast population in the world depends on not only agriculture, but also forestry, wetlands and fisheries and land use which, in turn, are strongly influenced by water based ecosystems that depend on monsoon rains. India is a global agricultural powerhouse. It is the world’s largest producer of milk, pulses, and spices as well as the largest area under wheat, rice and cotton. But increasing water scarcity in India is affecting agricultural sector, hence affecting socio- economic conditions of poor Indian farmers. In some pockets of the country, attempts have been made during the last few decades to manage the scarce water resources more efficiently and govern them more wisely, so that agriculture as the main economic backbone of the local communities can be sustainably supported. Ralegan Siddhi is one such outstanding case where the rainwater harvested through local interventions has enabled sustainable development of the entire community. The village stands out as an oasis in the desert. The aim of the study is to understand how water has been governed in Ralegan Siddhi to enable sustainable agriculture and hence sustainable development of the community. Ultimately, the study is foreseen to help improve the farmers’ situation in water scarce areas in India and elsewhere by sharing this study report based on Ralegan Siddhi’s water governance practices with other researchers as well as concerned agencies and actors.

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