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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.
151

Análise custo/benefício da adoção de boas práticas de manejo em pesque-pague / Cost-benefit analisys of best management practices use in fee fishing

Rosa, Daniele Klöppel 05 December 2008 (has links)
Made available in DSpace on 2016-06-02T18:57:26Z (GMT). No. of bitstreams: 1 2184.pdf: 10891858 bytes, checksum: 73f6b1a39daf89a3da77ee3132be166f (MD5) Previous issue date: 2008-12-05 / Universidade Federal de Minas Gerais / Fish culture is na aquaculture field which has been growing a lot in the last few years, specially by fish capture stagnation and for the growing high nutritional quality animal protein demand. A market field that has been greatly developed since 1990 s and which holds huge transactions of buying and selling alive cultures fish is the fee fishing activity, moving not only São Paulo fish cultures but from other states too, like Paraná, Mato Grosso do Sul and Minas Gerais. However, as in any human activity, it has negative and positive impacts. On this perspective, this study has objected, through an environment assessment evaluation in five fee-fishing units located in Araras region, manage the proposition Best Management Practices (BMP s) use and making a cost/benefit analysis to prove the viability of those practices use. Data were collected through a previous prepared questions and fishing pounds water and sediment samples analysis and water quality parameters measures in three different moments: before, during and after the rainy period. The analysis showed there are lead and iron elements excess in water, the former is due to previous lead contamination in Mogi-Guaçu hydrographical basin, and the last one because of the region soil type. Several Best Management Practices (BMP s) were proposed and the cost/benefit analysis identified only one economic viable establishment, whereas under a 9.5% a year discount rate in a 15-year analysis, it s proved to be profitable. The studied fee-fishing units presented serious problems on economic sector, and should in an urgent way improve their administrative and management strategies in order to better explore the property potentialities and the activity the execute in a sustainable manner. / A piscicultura é um ramo da aqüicultura que vem crescendo muito nos últimos anos, impulsionada pela estagnação na pesca extrativa e pela crescente demanda por proteína animal de alta qualidade nutricional. Um dos mercados que se desenvolveu copiosamente no início da década de noventa e que comporta grande movimentação de compra e venda de pescados cultivados é o mercado de pesque-pague, movimentando não só a piscicultura do estado de São Paulo, como também de estados vizinhos como Paraná, Mato Grosso do Sul e Minas Gerais. No entanto, assim como qualquer outra atividade humana, provoca impactos positivos e negativos. Sob esta perspectiva, este trabalho objetivou, através de uma avaliação de impactos ambientais em cinco pesque-pague da região de Araras, propor a adoção de boas práticas de manejo (BPM s) e realizar uma análise de custo/benefício para verificar a viabilidade da adoção de tais práticas. As informações foram coletadas através de questionários pré-elaborados, análises de amostras de água e sedimento e a medição dos parâmetros de qualidade de água dos tanques de pesca em três momentos diferentes: antes durante e após o período chuvoso. As análises de água revelaram existência de excesso dos elementos chumbo e ferro, o primeiro devido à contaminação pré-existente na bacia do Mogi-Guaçu, e o último em decorrência do tipo de solo da região latossolo. Várias Boas Práticas de Manejo foram propostas e a análise de custo/benefício identificou apenas um estabelecimento considerado economicamente viável, pois a uma taxa de desconto de 9,5% ao ano e sob um horizonte temporal de 15 anos, mostrou-se rentável. Os estabelecimentos estudados apresentam sérios problemas no setor econômico, devendo com urgência melhorar suas estratégias administrativas e gerenciais a fim de melhor explorar as potencialidades da propriedade e das atividades que desenvolvem de forma sustentável.
152

Drenagem urbana em áreas especiais: o caso da bacia fechada do bairro de Oitizeiro, João Pessoa. / Urban drainage in special areas: the case of the basin the closed neighborhood of Oitizeiro, João Pessoa.

Santos, Valéria Diniz dos 10 March 2006 (has links)
Made available in DSpace on 2015-05-14T12:09:40Z (GMT). No. of bitstreams: 1 parte2.pdf: 1500075 bytes, checksum: 38d49cb673692e0f852411fc280a488d (MD5) Previous issue date: 2006-03-10 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / Nowadays, problems including urban drainage are increasing with the percentage of urban area. In fact, the quality of life in big cities is directly affected by the drainage problems. In case of special areas, such as a closed watershed, the problems are increasing because in this sort of watershed there is not an outlet. This peculiar characteristic in its relief or its soil uses originates diversified questions about hidrology, sedimentology and water quality. In this paper, it was made a study about urban drainage problems in a watershed called Lagoa do Buracão, in the city of João Pessoa, State of Paraíba, Brazil. Each feature of the studied area was researched and several hydrological simulations were made in order to analyze three different sceneries of the soil occupation. The sceneries include changes in the level of the lake. It was used rainfall data and physical characteristics of the studied watershed. The results showed that the satisfactory scenery is the first one. Important positive impacts are involved with the proposed solution as well as negative impacts too. The main conclusion is that the proposal solution is highly recommendable for the resolution of the problem of urban drainage of Lagoa do Buracão. It adds other functions as the creation of a desirable landscape in the composition of the urban space, the valuation of the neighboring areas and the restoration of the environment which is currently degraded. / A problemática das inundações e dos alagamentos urbanos vem crescendo paulatinamente nas últimas décadas como conseqüência, principalmente, do crescimento das áreas urbanizadas. Logo, nota-se o comprometimento da qualidade de vida do habitante urbano, em particular no que tange aos transtornos causados pela presença de água em excesso nas vias e lotes urbanos. Tal situação agrava-se caso se considere a ocorrência desta problemática em bacias fechadas (ou endorreicas), uma vez que neste tipo de bacia o escoamento superficial se acumula em lagos ou sumidouros que não se comunicam por uma rede superficial com outros cursos de água a jusante. Constituem, desse modo, entes especiais na abordagem da gestão do meio urbano por não apresentarem uma saída natural para o escoamento das águas pluviais. A avaliação de áreas especiais fornece subsídios para a gestão do meio urbano, possibilitando o tratamento combinado das questões de drenagem pluvial com outras questões urbanísticas para o desenvolvimento sustentável. Na presente pesquisa, estudou-se a problemática da drenagem urbana de uma bacia fechada denominada Lagoa do Buracão, localizada no bairro de Oitizeiro, município de João Pessoa, Estado da Paraíba. Após caracterização detalhada dos diversos aspectos relativos à área enfocada e de variáveis hidrometeorológicas pertinentes, simulou-se o comportamento hidrológico-hidráulico do conjunto bacia-lagoa a partir da modelagem efetivada com o auxílio do Software ABC 6. São considerados três cenários propostos simulados a partir de uma cenário base, que corresponde a conformação atual da área. Os cenários propostos incluem desassoreamento e aprofundamento da lagoa. Os resultados mostraram que a alternativa mais adequada seria a do cenário 1, que abrange desassoreamento da lagoa para profundidade constante de 3 metros e soleira do vertedor na cota 30,5. Com base neste cenário eleito, propõe-se uma solução de drenagem para a lagoa de uso multifuncional, combinando a utilização de técnicas compensatórias de drenagem urbana e a inserção de elementos que propiciem a requalificação da paisagem urbana. São apontados ainda os principais impactos positivos e negativos esperados da implementação desta intervenção na bacia. Conclui-se que a solução proposta é altamente recomendável para a resolução do problema de drenagem urbana da Lagoa do Buracão, agregando outras funções como a criação de uma paisagem que valoriza as áreas do entorno e restaura um ambiente atualmente degradado.
153

Integrated Socio-Hydrological Modeling of and Understanding of Agricultural Conservation Practice Adoption in the Western Lake Erie Basin

Kast, Jeffrey Benjamin January 2021 (has links)
No description available.
154

An Examination of the Interconnected Social and Ecological Dimensions of Stormwater Management

Rachel D Scarlett (12224936) 20 April 2022 (has links)
<p>Land use change is a major cause of degradation to freshwater ecosystems. Excess nutrients and toxins, physical infrastructure, and habitat removal can lead to deleterious impacts on water quality, flooding, and biological integrity. The overarching inquiry of this dissertation was to assess how social and ecological dimensions of stormwater interact to influence stormwater and its management. A three-part study was conducted to investigate the ecological and social dynamics of aquatic ecosystems. In part one, I investigated the impacts of urbanization on stream metabolism— a fundamental ecological process. The proliferation of inexpensive water quality sensors has allowed researchers to investigate stream functional processes at a high temporal resolution. I used high-resolution dissolved oxygen data to estimate gross primary production (GPP) and ecosystem respiration (ER) across 12 urban creeks in Charlotte, North Carolina, USA. I used descriptive statistics and regression models to investigate the influence of light, temperature, and hydrological disturbances on GPP and ER. The results demonstrate that urbanization shifts metabolic regimes towards highly productive summers with substantial declines in GPP following summer storm events. My research shows that ER is associated with water temperature and is resistant to hydrological disturbances. These findings have management implications because as summer heat and storms intensify with climate change, my work suggests that stream organisms will become more vulnerable to scour and hypoxia.</p><p> </p><p>In part two, I conducted a systematic literature review to identify salient social norms impacting water quality best management practice (BMP) adoption across urban and rural lands. Furthermore, I synthesized situational factors that mobilize and reproduce social norms associated with BMP adoption. The results demonstrate that social norms create expectations for conventional farming practices and manicured residential lawns, as well as a social responsibility for neighborly cohesion and environmental stewardship. Social norms supporting water quality BMPs were fostered during times of management uncertainty and in response to social sanctions and benefits. I found that social norms supporting water quality BMPs were more readily mobilized when supported by key community leaders, knowledge brokers, and institutional actors.</p><p> </p><p>In part three, I examined if and how an individual’s race, gender, and education level shape one’s concern about and willingness to participate in stormwater management. Stormwater risks can be immediate burdens and at times life-threatening for marginalized people because environmental injustices based on race, gender, and class can dictate exposure to and recovery from environmental risks like flooding and water pollution. Although marginalized groups bear the brunt of environmental risks, they are not likely to be perceived by others as highly concerned about the environment. I investigated differences, if any, in peoples’ willingness to participate in stormwater management based on their race, gender, and educational level by analyzing community opinion surveys in Charlotte, North Carolina. Results suggest that socially marginalized individuals are more concerned about creek flooding than others and subsequently more likely to participate in conservation behaviors. This analysis calls attention to how adverse environmental conditions may shape the perspectives of those experiencing them and facilitate a greater willingness to engage in conservation practices. Collectively, this dissertation highlights the interconnectedness of human and ecological drivers of function and resilience in aquatic freshwater ecosystems with implications for future directions of freshwater management that prioritize social equity and sustain social infrastructures.</p>
155

Maintaining a Nitrogen Cap for Virginia's Potomac River: The Contribution of Alternative Development Patterns

Doley, Todd Michael 05 February 1999 (has links)
The Chesapeake Bay, once one of the worlds most productive estuaries, has been severely impacted by human activity in the water and on the lands around it. Viewed as an ecosystem, the Bay is no longer able to support the variety and abundance of biota that it was historically able to. Several decades of research on the Chesapeake have pointed to human activities as being the principle reason for this decline. Of these detrimental activities, elevated inputs of Nitrogen and Phosphorus to the Bay were singled out as being the greatest cause of water quality deterioration. The state of Virginia is trying to reduce its annual load of Nitrogen, to the Potomac River, to 60% of what the load was estimated to be in 1985. Virginia would like to accomplish this goal at the lowest cost to its citizens. Therefore the state needs to determine the combination of nitrogen control efforts which will achieve the goal at the lowest cost. The state would also like to be able to maintain nitrogen loads at or below this cap level, indefinitely into the future. This study was undertaken with three primary objectives. The first was to project the level of annual nitrogen inputs to the Potomac River, from the state of Virginia, over the next 15 years. The second was to estimate the minimum annual costs necessary to achieve and maintain a 40% reduction in total nitrogen inputs, using the Virginia's estimated 1985 inputs as a baseline. The final objective was to assess the potential cost savings that may result from using one of two alternative development patterns within the rapidly urbanizing Northern Virginia portion of the Potomac Watershed. The first alternative is prohibiting low-density development within the Northern Virginia region, and the second is to restrict all new development to be within 5 miles of an existing urban area. Study results suggest that there has been no significant progress toward meeting the nitrogen reduction goal, due to the increase in population within the watershed, over the past 13 years. To attain the goal in 1998, a minimum of $27 million, above what is currently being spent annually, would be required. Under the current land use trend within Virginia's Potomac Basin, the annual cost for maintaining the goal is estimated to rise to $38 million annually, in 1998 dollars, by the year 2013. This is a 40% increase in cost. If the first alternative development pattern is adhered to over this 15-year period, then the annual cost will be $33 million, for an annual cost saving of approximately $5 million in 2013. The second alternative could achieve similar results if implemented, costing roughly $5 million less in 2013 than the annual cost per year under the current trend. These findings suggest that the use of alternative development patterns can help slow but not prevent the annual cost, of maintaining the cap, from rising. The study indicates that the reason for the continuous rise in annual cost, over this fifteen-year period, is due primarily to an increase in nitrogen loading to the Potomac that will result from the wastewater disposal needs of the growing population within the Basin. Furthermore, the state will eventually exhaust its lower cost options for reducing Nitrogen loadings, and at that point the annual cost for maintaining the Nitrogen Cap will begin to rise exponentially. Under current land use trends this rapid rise in cost is unlikely to occur within the next 15 years, and is more apt to occur sometime within the next 20 to 40 years. Once annual expenditures begin to rise exponentially it is unlikely that the state of Virginia would be able to maintain its 40% reduction goal. / Master of Science
156

Assessing the relationship between soil health/quality and water quality in the Mississippi delta

Sarmiento Rodriguez, Laura Andrea 08 December 2023 (has links) (PDF)
Several studies have reported agronomic benefits by improving soil health/quality, but uncertain knowledge remains when determining specific impacts on water quality off-field. This study investigated the links between runoff water quality and soil health/quality in agricultural fields of the Mississippi delta under three land management scenarios: Conservation Reserve Program (CRP), vegetative buffer (VB), and row crops (RC). Using the Soil Management Assessment Framework (SMAF), a Soil Quality Index (SQI) was obtained based on ten soil health/quality indicators from 2008 and 2012 datasets. The SMAF identified significant differences in soil health/quality improvements among scenarios over a four-year period. Varied relationships between water quality parameters, SQI, and soil health/quality indicators were determined. Individually, physical and chemical soil indicators were also correlated with runoff water quality. Overall, the evidenced relationship between soil health/quality and water quality parameters was stronger in areas under CRP.
157

URBAN STORMWATER MANAGEMENT AND EROSION AND SEDIMENT CONTROL: AN INTERNSHIP WITH THE BUTLER SOIL AND WATER CONSERVATION DISTRICT

Thrash, Joel P. 19 April 2005 (has links)
No description available.
158

Urban Stormwater Quality Management and Education with an Emphasis in Erosion and Sediment Control: An Internship with Butler Soil and Water Conservation District

Dirksing, Douglas Michael 27 July 2007 (has links)
No description available.
159

An Expert System Approach to Best Management Practice Selection for Nominal Scale Low-Impact Redevelopments

Dicken, Christopher L. 26 September 2011 (has links)
No description available.
160

Soil Erosion from Forest Haul Roads at Stream Crossings as Influenced by Road Attributes

Lang, Albert Joseph 01 July 2016 (has links)
Forest roads and stream crossings can be important sources of sediment in forested watersheds. The purpose of this research was to compare trapped sediment and forestry best management practice (BMP) effectiveness from haul road stream crossing approaches and ditches. The three studies in this dissertation provide a quantitative assessment of sediment production and potential sediment delivery from forest haul roads in the Virginia Piedmont and Ridge and Valley regions. Sediment production rates were measured and modeled to evaluate and compare road and ditch segments near stream crossings with various ranges of road attributes, BMPs, and management objectives. Sediment mass delivered to traps from 37 haul road stream crossing approaches ranged from <0.1 to 2.7 Mg for the one year collection. Collectively, five approaches accounted for 82% of the total sediment mass trapped. Approaches were categorized into Low, Standard, and High road quality rankings according to road attributes. Seventy-one percent (5 of 7) of Low ranked approaches delivered sediment to traps at rates greater than 11.2 Mg ha-1 yr-1. Nearly 90% of Standard or High road quality approaches generated less than 0.1 Mg of sediment over one year. Among approaches with less than 0.1 Mg of trapped sediment, road gradients ranged from 1% to 13%, bare soil ranged from 2% to 94%, and distances to nearest water control structures ranged from 8.2 to 427.0 m. Such a wide spectrum of road attributes with relatively low levels of trapped sediment indicate that contemporary BMPs can mitigate problematic road attributes and reduce erosion and sediment delivery. Three erosion models, USLE-forest, RUSLE2, and WEPP were compared to trapped sediment data from the 37 forest haul road stream crossing approaches in the first study. The second study assessed model performance from five variations of the three erosion models that have been used in previous forest operations research, USLE-roadway, USLE-soil survey, RUSLE2, WEPP-default, and WEPP-modified. The results suggest that these soil erosion models could estimate erosion and sediment delivery within 5 Mg ha-1 yr-1 for most approaches with erosion rates less than 11.2 Mg ha-1 yr-1, while model estimates varied widely for approaches that eroded above 11.2 Mg ha-1 yr-1. Based on the results from the 12 evaluations of model performance, the modified version of WEPP consistently performed better compared to all other model variations tested. However, results from the study suggest that additional field evaluations and improvement of soil erosion models are needed for stream crossings. The soil erosion models evaluated are not an adequate surrogate for informing policy decisions. The third study evaluated sediment control effectiveness of four commonly recommended ditch BMPs on forest haul road stream crossing approaches. Sixty ditch segments near stream crossings were reconstructed and four ditch BMP treatments were tested. Ditch treatments were bare (Bare), grass seed with lime fertilizer (Seed), grass seed with lime fertilizer and erosion control mat (Mat), rock check dams (Dam), and completely rocked (Rock). Mat treatments had significantly lower erosion rates than Bare and Dam, while Rock and Seed produced intermediate levels. Findings of this study suggest Mat, Seed, and Rock ditch BMPs were effective at reducing erosion, but Mat was most effective directly following construction because Mat provided immediate soil protection measures. Any BMPs that reduce bare soil can provide reduction in erosion and even natural site condition, including litterfall and invasive vegetation can provide erosion control. However, ditch BMPs cannot mitigate inadequate water control structures. Overall, forest roads and stream crossings have the potential to be major contributors of sediment in forested watersheds when roads are not designed well or when BMPs are not properly implemented. Forestry BMPs reduce stormwater runoff velocity and volume from forest roads, but can have varying levels of effectiveness due to site-specific conditions. Operational field studies provide valuable information regarding erosion and sediment delivery rates, which helps guide BMP recommendations and subsequently enhances water quality protection. / Ph. D.

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