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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.
181

Comità das bacias hidrogrÃficas da regiÃo metropolitana de Fortaleza (CBH-RMF): trajetÃria e desafios para a gestÃo hÃdrica participativa / Committee of the watersheds in the metropolitan region of Fortaleza (CBH-RMF), trajectory and challenges for participatory water management

Amanda Benevides 18 May 2011 (has links)
FundaÃÃo Cearense de Apoio ao Desenvolvimento Cientifico e TecnolÃgico / Os comitÃs de bacia hidrogrÃfica â CBH foram instituÃdos no Brasil atravÃs da Lei n 9.433/97, a PolÃtica Nacional de Recursos HÃdricos, com o objetivo de possibilitar a participaÃÃo social na conduÃÃo do processo de gestÃo hÃdrica, por meio da representatividade de vÃrios setores da sociedade, que discutem e definem rumos para uma determinada bacia hidrogrÃfica onde vivem e atuam. Nesse contexto, foi feita uma anÃlise da trajetÃria do Comità das Bacias HidrogrÃficas da RegiÃo Metropolitana de Fortaleza â CBH-RMF, no Estado do CearÃ, com o intuito de compreender se a atuaÃÃo do referido comità tem obtido Ãxitos no encaminhamento de questÃes sobre os problemas ambientais das Bacias Metropolitanas, e quais as limitaÃÃes na articulaÃÃo das polÃticas e na efetivaÃÃo da gestÃo hÃdrica participativa. Como base para os estudos foram feitas pesquisas bibliogrÃficas, anÃlise de documentos, atas, entrevistas e observaÃÃo das reuniÃes do comitÃ. A pesquisa concluiu que o CBH-RMF deu passos relevantes, principalmente na elaboraÃÃo de diagnÃsticos e na realizaÃÃo de alguns encaminhamentos. Entretanto, essa polÃtica possui limitaÃÃes na sua implementaÃÃo, pois ainda à pouco divulgada e discutida com a sociedade. Faz-se necessÃrio maior articulaÃÃo institucional e participaÃÃo social para que sejam contempladas as visÃes e interesses da coletividade no tocante à gestÃo das Ãguas. / The river basin committees - CBH were established in Brazil by Law 9433/97, the National Policy of Water Resources, with the goal of enabling social participation in conducting the process of water management, through the representation of various sectors of society, to discuss and define paths for a given river basin where they live and work. In this context, We made an analysis of the trajectory of the Watershed Committee of the Metropolitan Region of Fortaleza - CBH-RMF, the state of Ceara, in order to understand whether the activities of that committee has been successful in addressing the problems environmental Metropolitan Watershed, and what limitations on the articulation of policies and in the effectiveness of participatory water management. As a basis for the studies we were performed literature searches, analysis of documents, records, interviews and observation of committee meetings. The research concluded that the CBH-RMF has taken relevant steps, especially in making diagnoses and conducting some procedures. However, this policy has limitations in its implementation because it is poorly distributed and discussed with the company. It is necessary to greater institutional coordination and social participation to reflect the views and interests of the community in relation to water management.
182

Doses de nitrogênio, Azospirillum brasilense e variação hídrica no feijoeiro de inverno submetido à hormese por glyphosate em diferentes formulações /

Silva, Juliano Costa da. January 2018 (has links)
Orientador: Ricardo Antonio Ferreira Rodrigues / Resumo: A busca de respostas da hormese em cultivos agrícolas tem encontrado inúmeras dificuldades, principalmente no que diz respeito à repetitividade dos resultados, em especial, em condições de campo. Assim, o trabalho teve como objetivo avaliar o efeito hormético de glyphosate no feijoeiro submetido a diferentes condições de estresse abiótico em cultivos à campo. Os experimentos foram conduzidos em áreas experimentais da Fazenda de Ensino Pesquisa e Extensão da Faculdade de Engenharia de Ilha Solteira - UNESP, em LATOSSOLO VERMELHO Distrófico típico argiloso. Os tratamentos para análise da influência da adubação no efeito hormético constaram da combinação da adubação nitrogenada de cobertura em sucessão a aplicação de subdoses de glyphosate na cultura do feijão. Os tratamentos com uso de bactérias e glyphosate constituíram-se da aplicação de uma subdose de glyphosate em diferentes formulações posteriormente a aplicação em cobertura ou não de Azospirillum brasilense. Por fim, os tratamentos para avaliação da influência da água no efeito hormético se deu pela aplicação de subdoses de glyphosate e lâminas de irrigação sobre o desenvolvimento, componentes de produção e produtividade do feijoeiro de inverno em Sistema Plantio Direto. Para tal foi utilizada a cultivar IPR – 139 do IAPAR. Concluiu-se que houve estímulo do crescimento do feijoeiro com aplicação de subdoses de até 14,4 g e.a. ha-1 de glyphosate, no entanto, o mesmo não ocorreu na presença do N em cobertura. O teor de N fo... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The search for hormesis responses in agricultural crops has found difficulties, especially with regard to the repeatability of the results, in particular, in field conditions. In this context, the objective was to evaluate the hormetic effect of glyphosate in common bean submitted to different conditions of abiotic stress and the use of techniques that can maximize results, such as the use of diazotrophic bacteria. The experiments were conducted in experimental areas of the farm Education Research and Extension of the Faculty of Ilha Solteira - UNESP in clayey Red Oxisol. The treatments for analysis of the influence of nitrogen fertilization on the hormetic effect consisted of the combination of nitrogen fertilization in succession to application of glyphosate subdoses in the common bean crop. The treatments with the use of bacteria and glyphosate were constituted of the application of glyphosate in different formulations after the application in cover or not of Azospirillum brasilense. Finally, the treatments to evaluate the influence of water on the hormetic effect were given by the application of glyphosate subdoses and irrigation slides on the development, production components and yield of the winter common bean under no-tillage system. For this, the cultivar IPR - 139 of IAPAR was used. It was concluded that there was stimulation of common bean growth with application of subdoses of up to 14.4 g ha-1 of glyphosate, however, the same did not occur in the presence of nitr... (Complete abstract click electronic access below) / Doutor
183

Exploring potential impacts of hydraulic fracturing (fracking) on groundwater contamination in the Karoo: perspectives on institutional capabilities in water management in South Africa

Chisebe, Khumbelo Britney January 2017 (has links)
A dissertation submitted in fulfilment of the requirements for the degree of Master of Environmental Science. with Witwatersrand University, Johannesburg, South Africa, (School of Geography, Archaeological and Environmental Science within the Faculty of Science) 2nd June 2017. / Hydraulic fracturing in the Karoo is said to be a game changer of energy sector in South Africa, but it is said to pose potential groundwater contamination. Therefore the aim of the study was to investigate the extent to which current institutional set up in South Africa can deal and address potential environmental challenges that are associated to fracking. The study was particularly interested in investigating the institutional capabilities in the context of water management. The literature review of this study showed that water resource is a major environmental concern that revolves around hydraulic fracturing, including the water resources use and potential contamination. In addition, it should be considered that hydraulic fracturing is a new mining process in South Africa and Africa as a whole with controversial mining techniques and environmental impacts involved within this process. The review indicates that the biggest issue with proposed hydraulic fracking mining process in the Karoo is if the South African Government has taken into consideration the resources, infrastructures and skills to execute the process successfully. The literature asserts that even if proper enforcement of any regulations on this rapidly expanding industry will still be difficult as the regulation is insufficient due to certain explicit exemptions. In South Africa, the starting point for hydraulic fracturing and the associated regulations that governs fracking, is the recognition of an argument that South Africa does not possess any fracking specific laws, guidelines or even polices. Research participants were asked to give their views on the research topic by answering the semi structured interview questions. Data from the semi-structured interviews and literature review was analysed and discussed to address the research questions. The results of the investigation confirmed that there was no any legislation in place to govern this mining process in South Africa. Currently there are legislations which are under review and development to also address hydraulic fracking and the protection of water resources. The government should also involve other research institutes in the drafting and decision making of the legal institute governing hydraulic fracking to ensure that all gaps are identified before fracking can be permitted in the Karoo. / MT 2017
184

Movement and Distribution of Juvenile Bull Sharks, Carcharhinus leucas, in Response to Water Quality and Quantity Modifications in a Florida Nursery

Ortega, Lori A 08 April 2008 (has links)
Movement, distribution, and habitat use of juvenile bull sharks were examined in two studies using manual and passive acoustic telemetry. Research was conducted in the Caloosahatchee River, which serves as nursery habitat for this species, and is highly impacted due to anthropogenic alterations in water quality and quantity via dams and locks. Manual tracking yielded fine-scale results for eight individuals on home range size, rate of movement, swimming depth, linearity, direction of travel, tidal influence, diel pattern, as well as correlation with environmental variables. Changes in salinity, temperature, dissolved oxygen, turbidity, and pH played a role on the distribution of bull sharks. Passive monitoring of twelve individuals allowed for examination of trends in residency, home range, depth, and distribution in response to water quality alterations. Both studies documented a shift in the distribution of animals in response to significant modifications in salinity and flow levels. Sharks were distributed throughout the river at low flow rates, but were located only near the river mouth, or exited the river at discharges rates above 75 m³s-1. Current water management policies are examined and recommendations are made which include the physiological preferences of this top-level predator.
185

The impact of agricultural drainage systems on hydrologic responses

Sheler, Rebecca Joy 01 May 2013 (has links)
Over the past century of settlement, the landscapes of the Midwestern United States have experienced extensive anthropogenic modifications in order to convert prior wetlands-lowlands to subsequent fruitful croplands. The hydrologic responses of these landscapes have been significantly altered by the installation of artificial drainage (surface ditches and subsurface tile drains) and the change in natural preferential flow paths (increased cracks or root holes due to land use practices). Changes to peak stream flow behaviors is a result of many different inter-related variables; however, intensified agricultural drainage remains one of the largest suspects. Though the effects of subsurface drainage (primarily in the form of tile drains) on landscape, hydrology, ecology, and economy have been questioned, theories of hydrologic controls continue to be vague at best. Soil-Water-Atmosphere-Plant, known as SWAP, was developed to simulate the interaction of vegetation development with the transport of water, solutes, and heat in the unsaturated zone. It is a one-dimensional, vertically directed model with a domain reaching from a plane just above the canopy to a plane in the shallow saturated zone. In the horizontal direction, the model's main focus is the field scale since most transport processes can be described in a deterministic way. The SWAP model was calibrated and validated for simulating flow regimes of drained and undrained landscapes in Iowa. A new term `flashiness' is used to characterize flow data. The Richards-Baker Flashiness Index quantifies the frequency and intensity of short term changes in streamflow. From the simulated results, the effect of anthropomorphic modifications to a landscape is determined to be strongly influenced by soil structural properties and hydraulic properties, along with rainfall regimes. Adding subsurface drains to soils with lower hydraulic conductivities, such as clay, tends to reduce peak flows during precipitation events. Conversely, adding drainage to soils with higher hydraulic conductivities, such as sand, increases peak flows. During years with heavy precipitation, soils with lower permeability show a `saddle shape' relationship between the flashiness index and the distance between tile drains produces. The lowest point of the `saddle' determines the ideal drain spacing for mitigating flashiness. When the shrinking and cracking of clay soils is considered, macropores dominate water flow pathways into the soil matrix and tile drains have a minimal effect on the flow regime. The volume of macropores at the surface of the soil profile is indirectly proportional to flashiness index. Independent of rainfall regimes, cropping season, and soil type, subsurface flows of drained landscapes always exceed that of undrained landscapes. Continuance of comprehensive studies of artificial subsurface drainage can produce positive impacts on engineering, economic, and ecological environments.
186

Analyzing Irrigation District Water Productivity by Benchmarking Current Operations Using Remote Sensing and Simulation of Alternative Water Delivery Scenarios

van Opstal, Jonna D. 01 May 2016 (has links)
Irrigation systems are designed to deliver water to crops, but their efficacy varies widely due to operational decisions, weather variability, and water availability. The operation of an irrigation system is studied in this dissertation to determine irrigation performance and potential for improvement.Satellite remote-sensing was used to determine inter-annual variability in crop evapotranspiration and link it with weather patterns and operational decisions. A decade was studied to include several dry, wet and average years of snowfall. It was found that the irrigation district has the capacity to buffer a dry year, but crop evapotranspiration patterns indicated that the buffer capacity of the irrigation district is limited in a second dry year. Studying the current operations of an irrigation system also requires an analysis of the spatial variability within the system to identify potential areas for improvement. Achieving such information is challenging due to the spatial heterogeneity between farm fields. The Ador irrigation system simulation model is used in this study with satellite remote sensing data, which were combined in the calibration and validation process to ease the re-adjustment of management parameters. This approach provides a cost-effective and innovative method for model simulation when field observations are limited. Alternative water delivery scenarios were simulated with the Ador irrigation system simulation model to quantify changes in the water balance, irrigation performance, and water productivity. Results for implementing a minimal irrigation time indicated that irrigation events occurred with a higher frequency and reduced crop water stress. Water productivity for the irrigation district increased substantially in this scenario, whilst district water savings were achieved by diverting less irrigation water. Advantages are only achieved if farmers collectively make the decision to change. A water accounting analysis is required to examine if water savings are achieved at basin scale. There is a potential for the rebound effect to occur, which suggests that an increase of water efficiency causes the increase of water consumption. Simulation results indicated that if the efficiency is increased through improvements of the water delivery, the water consumption increased. Water savings achieved by reducing irrigation diversions did not compensate for the decrease in drainage that downstream users depend on.
187

Land Use Dynamics and Implications for Water Management in the Urbanizing Wasatch Range Metropolitan Area of Utah

Li, Enjie 01 December 2017 (has links)
Utah is one of the fastest growing states in the USA. Utah’s Wasatch Range Metropolitan Area (WRMA), where 80% of Utah’s population resides, is growing at unprecedented rates and has seen extensive urban landscape transformation in the last half century. Many of Utah’s agricultural lands, grasslands, and wetlands have been transformed into urban areas during this time. Local residents have watched and experienced these changes to their local environment, but without a clear understanding of the processes and impacts of urbanization. It is not until we study these landscapes from a spatial perspective and the time scale of decades that we can begin to measure the changes that have occurred and predict the impact of changes to come if current trajectories continue. In this dissertation research I worked with my research colleagues to provide a comprehensive analysis of the WRMA’s past land use changes and future land use trends. In doing so, we: (1) measured the rate, the magnitude, and the process of past urban growth; (2) compared the changes of irrigated agricultural lands and non-irrigated agricultural lands in relation to urban development; and, (3) predicted how future urban growth could occur under various policy scenarios. We found that several counties at the heart of the WRMA have reached the limits of their capacity for future urban expansion. Thus, increasing urban density and land use efficiency will be key aspects of addressing the WRMA’s future growth. Also, variations of growth trends exist among and within the ten counties located in the WRMA, so it is necessary to develop contextualized and localized growth management plans. Furthermore, past land use dynamics prove that irrigated agricultural lands are more affected by urbanization than non-irrigated agricultural lands, with evidence of increasing agricultural lands fragmentation. Agricultural lands have been and will likely continue to be the major land source for future urban development. Utah’s public has indicated it wants to preserve agricultural lands to maintain open space and preserve cultural heritage, but this will require political attention and actions focused on areas where these lands are particularly vulnerable in the face of urban growth trajectories. The overall dissertation provides quantitative measurement of Utah’s urban landscape transformation and a science-based foundation for crafting successful land use policies to help guide future growth of the WRMA.
188

Agricultural Water Management in the Sevier River Basin, Utah: A Multidisciplinary Approach

Kim, Daeha 01 August 2015 (has links)
The Sevier River Basin situated in south central Utah is characterized by its semiarid climate, snowmelt-driven runoff, and high dependency on agricultural economy. High evapotranspiration and low precipitation make agricultural production challenging, but naturally stored water in the snowpack in the mountains alleviates water stresses during high water demand seasons. The snowmelt-driven river flow along the main channel is highly exploited for irrigation for farms near the Sevier River. Reservoir operations and river diversions result in heavily regulated flows from the upper to the lower basins. The return flows of over-irrigated water in the upper basin increase salinity of surface water. Long-term applications of salinity water in agriculture eventually produce high soil salinity in the agricultural areas near Delta in the lower basin, which deteriorated farmers’ crop productivity. Farmers cropping near Delta struggle with both water and salinity stresses. Indeed, crop prices and yields are always their concerns. For them, efficient water management can be achieved with consideration of hydrologic, agronomic, and economic aspects of water resources. The overall goal of this research was to develop a decision supporting framework for efficient water and land allocations that considered hydrologic processes, crop response to water in salinity-affected farms, and farmers’ profit and financial risk. This research introduces a methodology for predicting water availability in a given cropping year from the snowpack in the mountains, and agronomic simulations with satellite images follow for quantifying crop response to water. The hydrologic predictions and the agronomic simulations are finally incorporated into an economic analysis that provides efficient water and land allocations with multiple crop selections. In a rural river basin, data limitation is a common concern for water resources engineers; thus simple but robust methodologies are proposed for hydrologic prediction. In the same context, satellite images are used for the estimation of crop yields in individual farms near Delta with no prior crop experimental plots. Historical records of crop prices are used for the economic analysis. The methodologies developed in this research provide a comprehensive decision analysis framework for efficient water management where water is scare and available from snowmelt only, the economy depends on agriculture only, and salinity is present in both soil and water due to long-term irrigation. The case study is for the agricultural area near Delta in the Sevier River Basin, but its applicability is not limited and is flexibly applicable to other agricultural regions.
189

Seasonal Transport of Suspended Solids and Nutrients Between Bear River and Bear Lake

Allen, Cody M. 01 December 2011 (has links)
Dingle Marsh is a wetland complex separating the Bear River from Bear Lake. Flow direction through the marsh is controlled at four major inflow and outflow sites. These sites were chosen as monitoring sites to assess the suspended solid and nutrient transport through the marsh. High frequency turbidity measurements were collected at each site and used as a surrogate for total phosphorus (TP) and total suspended solid (TSS) concentrations. Loads of TP and TSS were calculated using flow data from the 2008 water year. Load calculations for TP and TSS were compiled at 30-minute intervals and annual mass balances were calculated for Dingle Marsh and Bear Lake. These calculations were used to identify the seasonal loading patterns within this system. This study found the majority of TSS and TP loading entered the marsh from the Bear River. As flows moved across the marsh, the loading of TSS and TP was greatly reduced. Seasonal flow patterns were analyzed to determine the loading patterns to Dingle Marsh, Bear Lake, and the Bear River. This study also identified water management strategies aimed at setting a target endpoint for TSS and TP loads.
190

Terminologie et discours spécialisés : les vocabulaires de la « gestion de l’eau » en français et leur incidence en traduction arabe / Terminology and specialized discourse : the vocabularies of water management in French And their translation incidence into Arabic

Salim, Chaza 10 December 2010 (has links)
Ce travail s’inscrit essentiellement dans le cadre de la terminologie en ce qu’elle utilise et étudie les termes. A partir des propositions de la terminologie, de la traductologie, ainsi que ceux de la praxématique, nous menons une étude sur la terminologie scientifique et technique du vocabulaire de la gestion de l’eau en français (FR) et en arabe (AR). Notre objectif principal est de rapprocher le terme du praxème à partir de leurs fonctionnements discursifs. L’analyse est sémantique puisque nous étudions le comportement du terme en discours. Différents niveaux de discours se distinguent par le biais de différents phénomènes discursifs. Nous avons effectué un essai de catégorisation des genres de discours de la gestion de l’eau en français, et l’avons comparé à celui du corpus arabe. Des paires d’équivalents termes FR/AR sont établies ouvrant un autre horizon d’études terminologiques et traductologiques. / The present work generally subscribes into the terminology frames (studies and uses of terms). From the propositions of terminology, translatology as well as praxematics, we have conducted a study of scientific and technical terminology applied to the water management vocabulary in French (FR) and Arabic (AR). Our main objective is to bring closer the term to the “praxème” from their discursive behaviors. The analysis is semantic because we have studied the behavior of the term in discourse. Different levels of discourses are distinguished through the discursive recurring phenomena. We have conducted a test of discursive genre categorizations in French, and compared it with the Arabic data. Pairs of equivalent terms FR/AR have settled other new horizons in terminology and translatology studies.

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