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Developing Controlled-release Hydrogen Peroxide for On-site Treatment of Organic Pollutants in Urban Storm RunoffSun, Siying 03 October 2011 (has links)
No description available.
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Simulação de escoamento e de produção de sedimentos em uma microbacia hidrográfica utilizando técnicas de modelagem e geoprocessamento. / Streamflow and sediment yield simulation within a small watershed through geoprocessing and modeling techniques.Machado, Ronalton Evandro 06 March 2002 (has links)
Modelos hidrológicos e de qualidade de água vêm sendo desenvolvidos para avaliar a poluição causada por fontes de origem difusa, em bacias hidrográficas agrícolas. Com esse objetivo, o modelo SWAT (Soil and Water Assessment Tool) foi aplicado para simular o escoamento e a produção de sedimentos produzidos pela microbacia hidrográfica do Ribeirão dos Marins, afluente do rio Piracicaba, SP, no biênio 1999/2000. A aplicação do modelo requer a entrada dos dados na forma espacializada. A manipulação desses dados foi feita com o auxílio de um Sistema de Informações Geográficas (SIG) e uma interface entre o modelo e o SIG que, automaticamente, subdivide a bacia em sub-bacias a partir do Modelo Numérico do Terreno (MNT) e, então, extrai os dados de entrada relacionados para cada sub-bacia dos outros Planos de Informação (PIs), uso da terra e solos, associados a um extenso banco de dados. Posteriormente, os resultados finais da simulação são apresentados no formato de mapas, gráficos e tabelas. Os resultados obtidos da simulação, médias mensais do escoamento e a produção de sedimentos, foramcomparados aos dados observados em um posto hidrossedimentométrico localizado no terço superior da microbacia, utilizando o Coeficiente de Eficiência de Nash e Sutcliffe (COE) e o desvio dos dados simulados em relação aos observados (Dv). Foi feita uma calibração de alguns parâmetros físico-hídricos do solo e físico das sub-bacias, para as duas variáveis simuladas. Dois cenários alternativos de uso da terra foram simulados. No primeiro, o uso atual foi mantido, mas considerou-se uma faixa de mata ciliar de 30m em toda a extensão dos cursos dágua e de 50m ao redor das nascentes, de acordo com o Código Florestal. No segundo cenário, como as pastagens ocupam as encostas mais íngremes, com alto potencial erosivo, as áreas ocupadas por pastagem foram substituídas por vegetação florestal. As simulações dos dois cenários foram comparadas com as condições do cenário atual em termos de redução da produção de sedimentos. Os resultados obtidos para o escoamento simulado foram de 0,92 e -0,7% para o COE e o Dv, respectivamente, após a calibração. Na simulação da produção de sedimentos pelo modelo, após a calibração, o COE obtido foi de 0,83 e o Dv de -3,2%. Os cenários produziram diferentes padrões espaciais da produção de sedimentos. Uma redução de 84,4% na produção de sedimentos foi obtida com a substituição da pastagem por vegetação nativa (cenário 2). No cenário 1, a redução foi de 10,8%. Esses resultados evidenciam a necessidade de se tratar a paisagem em bacias hidrográficas de uma forma global, identificando as "áreas ambientalmente sensíveis", onde são necessárias práticas de controle dos processos erosivos e não somente com a proteção dispensada aos cursos dágua por meio da mata ciliar. / Hydrological and water quality models have been developed to evaluate the nonpoint source pollution in agricultural watershed. With this objective, SWAT (Soil and Water Assessment Tool) model was applied to simulate the streamflow and sediment yield in Ribeirão dos Marins watershed, on the Piracicaba river basin, Brazil, for the period 1999/2000. The application of the model requires the input data in spatial format. The manipulation of these data was made with an interface between the model and the Geographic Information System (GIS) that, automatically, subdivides the basin in subbasins, from the Digital Terrain Model (DTM) and extracts the input data for each subbasin from the land use and soil layers. Later, the results of the simulation are presented in the format of maps, graphs and tables. The results of the simulation, monthly averages of the streamflow and the sediment yield, were compared to the observed data in a gauge station located in Ribeirão dos Marins watershed, using the Nash Sutcliffe Coefficient (COE) and the deviation of the simulated data in relation to the observed data (Dv). A calibration of some physical-hydrological parameters of soil and physical of the subbasins was made for the two variables simulated. Two alternative scenarios of land use have been simulated. In the first, the current land use was kept, with a riparian buffer of 30m along of the drainage network and of 50m around the springs, in accordance with the Forest Code. In the second scenario, as the pastures occupy the steepest hillsides, with high erosive potential, pastures were changed by native forest. The simulations of the two scenarios were compared to the current scenario, regarding the reduction of sediment yield. The results of the simulated streamflow were of 0,92 and -0,7% for the COE and the Dv, respectively, after the calibration. In the simulation of the sediment yield, after the calibration, the COE was 0,83 and Dv was -3,2%. The scenarios produced different spatial patterns of the sediment yield. The reduction in sediment yield of 84,4% was obtained with the substitution of the pasture by native vegetation (scenario 2). In scenario 1, the reduction was of 10,8%. These results show that is necessity to manage watershed considering the whole landscape aspects, identifying environmentally sensitive areas, mainly in relation to erosion, instead of protecting only riparian areas.
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Efficacité et acceptabilité de la régulation de la pollution diffuse : expériences sur des variantes coopératives de type « taxe ambiante » / Efficiency and acceptability in the regulation of non-point source pollution : experiments on cooperative ambient-based instruments.Sarr, Hamet 30 May 2013 (has links)
L’objectif du travail de thèse a été de tester en laboratoire l’efficacité de deux variantes de taxe ambiante (Taxe Pigouvienne Moyenne et Taxe Ambiante Plafonnée) qui présentent l’avantage de réduire les charges en cas de taxation mais dont l’efficacité nécessite que les pollueurs coordonnent leurs efforts. Pour permettre cette coordination, trois formes de communication (communication gratuite ou « cheap talk », communication coûteuse endogène et exogène) ont été testées. Les résultats montrent que le sucker’s payoff et la taille des groupes sont déterminants dans le potentiel du cheap talk à induire de la coopération. Lorsque la communication est coûteuse et exogène, l’impact positif de la communication est limité dans le temps. Cependant lorsque la décision de communiquer moyennant un coût revient aux joueurs, ceux-ci choisissent de ne pas communiquer. Nous avons aussi montré que le cheap talk facilite la coordination vers l’équilibre Pareto-dominant et rend ainsi la Taxe Ambiante Plafonnée efficace. / The purpose of this thesis was to test in laboratory the efficiency of two variants of the ambient tax (Average Pigovian Tax and Capped Ambient Tax) that present the advantage of reducing the financial burden imposed through taxation but whose efficiency requires that polluters coordinate their efforts. To enable this coordination, three types of communication (“cheap talk” or costless communication, exogenous costly communication and endogenous costly communication) are tested.The results show that the sucker’s payoff and the size of the groups are crucial in the potential of cheap talk to induce cooperation. When the communication is costly and exogenous, cooperation is limited in time. However when the decision to communicate for a price is up to the players, they decide not to communicate. We’ve also shown that cheap talk facilitates coordination towards the Pareto-dominant equilibrium and makes the Capped Ambient Tax efficient.
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Efeitos espaço temporais da poluição pontual e não pontual em uma bacia hidrográfica subtropical : ecohidrologia como ferramenta de controleGatti Junior, Pedro 27 July 2015 (has links)
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Previous issue date: 2015-07-27 / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / Contaminants are introduced into aquatic ecosystems, both from point and diffuse sources and usually are deposited in the sediments of lakes and reservoirs. The input of diffuse pollutants in the environment is of difficult control and identification, while the control of point sources is more efficient because they are easily identified. However, the frequent discharges of effluents, althought undergoing treatment, may change the input of elements and substances in a given region. The aim of this study was to assess the spatial-temporal influence of point and non-point source pollution on the characteristics of surface water and sediment in a watershed with well-marked seasons. In addition, concepts and attempts at ecosystems restoration in different regions were reviewed in order to understand the main drivers of abiotic-biotic regulation among watersheds and aquatic ecosystems, based on the principles of Ecohydrology. For this purpose, the concentrations of Cd, Cr, Fe, Ni, Zn, Pb, Al, Cu, Mn, Hg, As, Se, total
phosphorus, total nitrogen and ions in water and sediment were examined. Furthermore, levels of metals (Al, Fe, Mn, Cu, Zn, Hg and As) in the sediment profile of stations under of the influence of different impact were evaluated. This study showed that the point source pollution promote a high load of contaminants in sediment, regardless of the season. Furthermore, the point pollution sources seem to be spatially and temporally the main cause of reservoir sediment chemical composition due its frequent effluent release. This study also indicates that, despite several biogeographical differences, hydrology seems to be the main factor that controls the primary and secondary production and sustainability in rivers and lakes (reservoirs). In conclusion, the hydrology in the tropics seems to decrease the expected effects of a higher temperature. Therefore, to increase resilience in tropical freshwaters integrated actions according to hydrological stages are highly recommended. / Contaminantes são introduzidos em ecossistemas aquáticos, a partir de fontes pontuais e difusas e geralmente são depositados nos sedimentos de lagos e reservatórios. A entrada de poluentes difusos no ambiente é de difícil controle e identificação, enquanto que o controle de fontes pontuais é mais eficiente, pois são facilmente identificados. No entanto, as frequentes descargas de efluentes, mesmo passando por tratamento, podem mudar a dinâmica de entrada de elementos e substâncias em uma região. O objetivo deste estudo foi avaliar a influência espaço-temporal de fontes de poluição pontual e não pontual nas características das águas superficiais e do sedimento de um reservatório (Lobo/Broa, SP) em uma bacia hidrográfica com estações climáticas bem definidas. Além disso, conceitos e tentativas de restauração em diferentes ecossistemas foram revisados com o objetivo de entender quais são os principais controladores da regulação abiótica-biótica entre bacias hidrográficas e ecossistemas aquáticos, com base nos princípios da Ecohidrologia. Para este propósito, as concentrações de Cd, Cr, Fe, Ni, Zn, Pb, Al, Cu, Mn, Hg, As, Se, fósforo total, nitrogênio total e íons na água e no sedimento foram examinadas. Além disso, os níveis de metais (Al, Fe, Mn, Cu, Zn, Hg e As) no perfil do sedimento de pontos amostrais sob influência de diferentes impactos foram avaliados. Este estudo mostrou que as fontes pontuais de poluição promovem uma alta carga de contaminantes nos sedimentos, independentemente da estação. Além disso, as fontes de poluição pontual parecem ser espacialmente e temporalmente as principais causa da composição química de sedimentos do reservatório por causa da frequente liberação de efluentes. Esse estudo também indica que, apesar de várias diferenças biogeográficas, a hidrologia parece ser o principal fator que controla a produção primária, secundária e a sustentabilidade em rios e lagos (reservatórios). Em conclusão, a hidrologia nos trópicos parece diminuir os efeitos esperados de uma temperatura mais elevada. Portanto, para aumentar a resiliência nas águas doces tropicais ações integradas de acordo com as fases hidrológicas são altamente recomendadas.
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Simulação de escoamento e de produção de sedimentos em uma microbacia hidrográfica utilizando técnicas de modelagem e geoprocessamento. / Streamflow and sediment yield simulation within a small watershed through geoprocessing and modeling techniques.Ronalton Evandro Machado 06 March 2002 (has links)
Modelos hidrológicos e de qualidade de água vêm sendo desenvolvidos para avaliar a poluição causada por fontes de origem difusa, em bacias hidrográficas agrícolas. Com esse objetivo, o modelo SWAT (Soil and Water Assessment Tool) foi aplicado para simular o escoamento e a produção de sedimentos produzidos pela microbacia hidrográfica do Ribeirão dos Marins, afluente do rio Piracicaba, SP, no biênio 1999/2000. A aplicação do modelo requer a entrada dos dados na forma espacializada. A manipulação desses dados foi feita com o auxílio de um Sistema de Informações Geográficas (SIG) e uma interface entre o modelo e o SIG que, automaticamente, subdivide a bacia em sub-bacias a partir do Modelo Numérico do Terreno (MNT) e, então, extrai os dados de entrada relacionados para cada sub-bacia dos outros Planos de Informação (PIs), uso da terra e solos, associados a um extenso banco de dados. Posteriormente, os resultados finais da simulação são apresentados no formato de mapas, gráficos e tabelas. Os resultados obtidos da simulação, médias mensais do escoamento e a produção de sedimentos, foramcomparados aos dados observados em um posto hidrossedimentométrico localizado no terço superior da microbacia, utilizando o Coeficiente de Eficiência de Nash e Sutcliffe (COE) e o desvio dos dados simulados em relação aos observados (Dv). Foi feita uma calibração de alguns parâmetros físico-hídricos do solo e físico das sub-bacias, para as duas variáveis simuladas. Dois cenários alternativos de uso da terra foram simulados. No primeiro, o uso atual foi mantido, mas considerou-se uma faixa de mata ciliar de 30m em toda a extensão dos cursos dágua e de 50m ao redor das nascentes, de acordo com o Código Florestal. No segundo cenário, como as pastagens ocupam as encostas mais íngremes, com alto potencial erosivo, as áreas ocupadas por pastagem foram substituídas por vegetação florestal. As simulações dos dois cenários foram comparadas com as condições do cenário atual em termos de redução da produção de sedimentos. Os resultados obtidos para o escoamento simulado foram de 0,92 e 0,7% para o COE e o Dv, respectivamente, após a calibração. Na simulação da produção de sedimentos pelo modelo, após a calibração, o COE obtido foi de 0,83 e o Dv de 3,2%. Os cenários produziram diferentes padrões espaciais da produção de sedimentos. Uma redução de 84,4% na produção de sedimentos foi obtida com a substituição da pastagem por vegetação nativa (cenário 2). No cenário 1, a redução foi de 10,8%. Esses resultados evidenciam a necessidade de se tratar a paisagem em bacias hidrográficas de uma forma global, identificando as "áreas ambientalmente sensíveis", onde são necessárias práticas de controle dos processos erosivos e não somente com a proteção dispensada aos cursos dágua por meio da mata ciliar. / Hydrological and water quality models have been developed to evaluate the nonpoint source pollution in agricultural watershed. With this objective, SWAT (Soil and Water Assessment Tool) model was applied to simulate the streamflow and sediment yield in Ribeirão dos Marins watershed, on the Piracicaba river basin, Brazil, for the period 1999/2000. The application of the model requires the input data in spatial format. The manipulation of these data was made with an interface between the model and the Geographic Information System (GIS) that, automatically, subdivides the basin in subbasins, from the Digital Terrain Model (DTM) and extracts the input data for each subbasin from the land use and soil layers. Later, the results of the simulation are presented in the format of maps, graphs and tables. The results of the simulation, monthly averages of the streamflow and the sediment yield, were compared to the observed data in a gauge station located in Ribeirão dos Marins watershed, using the Nash Sutcliffe Coefficient (COE) and the deviation of the simulated data in relation to the observed data (Dv). A calibration of some physical-hydrological parameters of soil and physical of the subbasins was made for the two variables simulated. Two alternative scenarios of land use have been simulated. In the first, the current land use was kept, with a riparian buffer of 30m along of the drainage network and of 50m around the springs, in accordance with the Forest Code. In the second scenario, as the pastures occupy the steepest hillsides, with high erosive potential, pastures were changed by native forest. The simulations of the two scenarios were compared to the current scenario, regarding the reduction of sediment yield. The results of the simulated streamflow were of 0,92 and 0,7% for the COE and the Dv, respectively, after the calibration. In the simulation of the sediment yield, after the calibration, the COE was 0,83 and Dv was 3,2%. The scenarios produced different spatial patterns of the sediment yield. The reduction in sediment yield of 84,4% was obtained with the substitution of the pasture by native vegetation (scenario 2). In scenario 1, the reduction was of 10,8%. These results show that is necessity to manage watershed considering the whole landscape aspects, identifying environmentally sensitive areas, mainly in relation to erosion, instead of protecting only riparian areas.
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Residents’ knowledge, perceptions, attitudes, and willingness to pay for non-point source pollution control: a study of Nansihu Lake Watershed, ChinaHao, Jianjun 07 January 2008 (has links)
No description available.
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Costs of Meeting Water Quality Goals under Climate Change in Urbanizing Watersheds: The Case of Difficult Run, VirginiaGiuffria, Jonathon Michael 28 June 2016 (has links)
Urban environments have been identified as a non-point source contributor of nutrient loadings into watersheds. Interannual surges of nutrient loadings into local water systems are more damaging than mean interannual nutrient loadings. Virginia has outlined the need to reduce urban nutrient loadings. Mean interannual nutrient loadings and interannual nutrient loadings variability are expected to increase under climate change (CC). However, there are few studies that provide a predictive framework for abating nutrient loadings under CC. Thus, there is a lack of information regarding how effective water quality policy will be in the future. Using the Difficult Run watershed in Fairfax County, VA, as a site of study, we used mathematical programming to compare how the costs of abating nutrient loads differed under differing climates in the Mid-Atlantic. We first compared the costs of abating mean interannual nutrient loadings in the watershed based on historical climate conditions to those predicted for CC. We then evaluated how changes in the interannual variability of nutrient loadings for CC affect the costs of meeting watershed goals. We found that abating mean interannual nutrient loadings was substantially costlier for CC relative to meeting the same goals under historical climate conditions. Further, we found that the costs of abating interannual nutrient loadings variability increased under CC relative to meeting the same goals under historical climate. One implication of this study suggests that policy makers seeking to meet water quality goals over time must front-load supplemental BMPs today in order to offset the changes predicted for CC. / Master of Science
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Environmental and Economic Impacts of Chemical Fertilizer Use: A Case Study of the North China PlainPowell, Jane Elizabeth 14 August 2018 (has links)
No description available.
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An assessment of the contribution of agricultural non-point source pollution on the water quality of the Vaal River within the Grootdraai Dam catchmentNcube, Scott 26 January 2015 (has links)
This study assesses the contribution of agricultural non-point source pollution, to poor water
quality of the Vaal River within the Grootdraai dam catchment area. The study evaluates
agricultural pollutants affecting the quality of water within the study area. The impact of
agricultural non-point source pollution on the water quality of the Vaal River was evaluated
by establishing a correlation between the quantity of polluted runoff reaching the River and
the quantity of measured nitrates and phosphates in its waters. A questionnaire using random
sampling was used to capture data from 15 commercial farmers 35 local residents and the
Department of Water Affairs management. The results of the study show that agricultural
nutrients are heavily impacting and compromising the water quality of the Grootdraai Dam.
The mean concentrations of Nitrogen and Phosphorus were found to be well above the water
quality guidelines there by promoting eutrophication. / Environmental Sciences / M. Sc. (Environmental Management)
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An assessment of the contribution of agricultural non-point source pollution on the water quality of the Vaal River within the Grootdraai Dam catchmentNcube, Scott 26 January 2015 (has links)
This study assesses the contribution of agricultural non-point source pollution, to poor water
quality of the Vaal River within the Grootdraai dam catchment area. The study evaluates
agricultural pollutants affecting the quality of water within the study area. The impact of
agricultural non-point source pollution on the water quality of the Vaal River was evaluated
by establishing a correlation between the quantity of polluted runoff reaching the River and
the quantity of measured nitrates and phosphates in its waters. A questionnaire using random
sampling was used to capture data from 15 commercial farmers 35 local residents and the
Department of Water Affairs management. The results of the study show that agricultural
nutrients are heavily impacting and compromising the water quality of the Grootdraai Dam.
The mean concentrations of Nitrogen and Phosphorus were found to be well above the water
quality guidelines there by promoting eutrophication. / Environmental Sciences / M. Sc. (Environmental Management)
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