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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.
261

Avaliação da variabilidade de qualidade ambiental de bacias de mananciais de abastecimento público com a aplicação de um índice para o estado de Goiás / Evaluation of environmental quality of water supple watershed basins by appliction of variability measure index for the state of Goiás

Cruvinel, Karla Alcione da Silva 31 March 2016 (has links)
Submitted by Marlene Santos (marlene.bc.ufg@gmail.com) on 2016-09-08T16:58:41Z No. of bitstreams: 2 Tese - Karla Alcione da Silva Cruvinel - 2016.pdf: 6969385 bytes, checksum: e3b015b1a1c9a8dd5fc6ec8b43f1bb62 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2016-09-09T14:38:30Z (GMT) No. of bitstreams: 2 Tese - Karla Alcione da Silva Cruvinel - 2016.pdf: 6969385 bytes, checksum: e3b015b1a1c9a8dd5fc6ec8b43f1bb62 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2016-09-09T14:38:30Z (GMT). No. of bitstreams: 2 Tese - Karla Alcione da Silva Cruvinel - 2016.pdf: 6969385 bytes, checksum: e3b015b1a1c9a8dd5fc6ec8b43f1bb62 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2016-03-31 / Fundação de Amparo à Pesquisa do Estado de Goiás - FAPEG / The need for environmental preservation and responsible use of natural resources is something increasingly discussed between civil society and the scientific community and the need to monitor the environmental quality of areas such as river basins requires planning and choice of variables that help in understanding functionality of these systems. In addition, the index and indicators are presented as efficient tools in order to make them more easily visualized technical data. In this study, socioeconomic and environmental indicators were used in order to structure an index able to estimate the degree of environmental quality of the watershed. The Environmental basins Quality Index (EQI) was built from the variables Soil Loss (SL), Native Vegetation Index (NVI), Water Quality Index (WQI) and Municipal Development Index (MDI). The GIS was used to identify the NVI and loss of soil in the basin, and for the latter employed Universal Soil Loss Equation (USLE). It was applied still Soil and Water Assessment Tool software (SWAT) in soil loss prediction five basins studied in order to promote the direct comparison of the model front applicability of the method implemented USLE. We studied different scenarios in these same five basins in SWAT, which we sought to evaluate the influence of vegetation in sediment yield for different land cover scenarios. To obtain the WQI of each basin, we used the adaptation of the method developed by Sousa (2014). After that, the EQI was applied in 126 basins of supply water sources in Goias State, which enabled the identification of the degree of environmental quality of each. It was found that almost 85% of the studied basins are classified as very bad or bad EQI, and in almost all of these the WQI of the spring is also bad. By analyzing the EQI basins in ten different regions of Goias State Planning it was noted that average is best in the Northwest region, which also has better native state of vegetation index. Regarding the loss of soil, it is noted that most of the basins (64%) are classified in low and moderate erosive susceptibility, but with some in erosive susceptibility very high severe. Therefore, it was concluded that the methodology used in this study proved to be an effective management strategy for catchments and can be used as an environmental planning instrument in these areas. / A importância de conservação ambiental e o uso consciente de recursos naturais é algo cada vez mais discutido entre a sociedade civil e comunidade científica. Existe uma necessidade urgente do monitoramento da qualidade ambiental de áreas como bacias hidrográficas, o que requer planejamento e escolha de variáveis que auxiliem no entendimento da funcionalidade desses sistemas. Desta forma, os índices e indicadores apresentam-se como ferramentas eficazes, no sentido de tornar os dados técnicos mais facilmente visualizados. Assim, neste estudo foram utilizados indicadores socioeconômicos e ambientais, com o objetivo de estruturar um índice capaz de estimar o grau de qualidade ambiental de bacias hidrográficas. O Índice de Qualidade Ambiental de Bacias (IQAB) foi construído a partir das variáveis Perda de Solo (PS), Porcentagem de Vegetação Nativa (PVN), Índice de Qualidade da Água (IQA) e Índice de Desenvolvimento dos Municípios (IDM). Foi utilizado o Geoprocessamento na identificação do PVN e da perda de solo nas bacias, sendo que para este último empregouse a Equação Universal de Perda de Solos (EUPS). Aplicou-se ainda o software Soil and Water Assessment Tool (SWAT) na predição de perda de solo de cinco das bacias estudadas, a fim de promover a comparação da aplicabilidade direta deste modelo frente ao método implementado EUPS. Estudou-se a mudança de cenários nestas mesmas cinco bacias, no SWAT, onde se buscou avaliar a influência da vegetação na produção de sedimentos para diferentes cenários de cobertura vegetal. Para a obtenção do IQA de cada bacia, utilizou-se a adaptação do método desenvolvido por Sousa (2014). Após a sua construção, o IQAB foi aplicado em 126 bacias de mananciais de abastecimento do estado de Goiás, o qual possibilitou a identificação do grau de qualidade ambiental de cada uma. Verificou-se que quase 85% das bacias estudadas estão classificadas em IQAB péssimo ou ruim, sendo que em quase todas estas o IQA do manancial também é ruim. Ao analisar o IQAB das bacias nas dez diferentes regiões de Planejamento do estado de Goiás, observou-se que a melhor média é na região Noroeste, a qual também possui melhores PVN do estado. Com relação a perda de solo, nota-se que maior parte das bacias (64%) estão enquadradas na susceptibilidade erosiva baixa e moderadas, mas com algumas em susceptibilidade erosiva muito alta a severa. Portanto, conclui-se que a metodologia utilizada neste trabalho mostrou ser uma eficiente estratégia de gestão para bacias hidrográficas podendo ser utilizada como instrumento de planejamento ambiental dessas áreas.
262

Caracterização hidrológica e dinâmica do nitrogênio em uma microbacia com cobertura florestal (Mata Atlântica), no Parque Estadual da Serra do Mar, núcleo Santa Virgínia / Hydrological functioning and nitrogen dynamics of a small catchment covered by Atlantic rainforest within the State Park of Serra do Mar, Santa Virgínia Stewardship

Juliano Daniel Groppo 17 August 2010 (has links)
A Mata Atlântica, um dos ecossistemas mais ameaçados do planeta, reduzida atualmente a menos de 8% de sua cobertura original, necessita atenção especial em termos de compreensão do seu funcionamento como subsídio para sua melhor conservação. O presente estudo além de expandir a quantidade de estudos realizados nessa região, visou caracterizar o funcionamento hidrológico e a dinâmica do nitrogênio de uma microbacia com cobertura de Mata Atlântica no litoral norte do Estado de São Paulo. Para isso, foram monitorados alguns processos hidrológicos, entre eles: escoamento superficial, umidade do solo (0,15, 0,30, 0,50 e 0,90 metros de profundidade), água subterrânea, transprecipitação, precipitação e vazão, entre os anos de 2008 e 2009. Com o intuito de elucidar os processos hidrológicos que geram escoamento direto, mediu-se a condutividade hidráulica do solo (Ksat) nas mesmas profundidades da umidade do solo, com um permeâmetro de carga constante. Adicionalmente foi utilizado um sistema de injeção em fluxo (FIA) para a análise de nitrogênio inorgânico (N-NH4 + e N-NO3 -) e para a análise do nitrogênio total dissolvido (NTD) foi utilizado o TOC (Total Organic Carbon Analyser). A precipitação total no ano de 2008 foi de 1716 mm, aproximadamente 33% foi interceptada pela floresta e 67% chegam à superfície do solo. O deflúvio total foi de 681 mm, dessa forma o coeficiente de deflúvio foi de aproximadamente 40% da precipitação, sendo o restante perdido por evapotranspiração (1035 mm.ano-1). Já o ano de 2009, a precipitação foi de 3003 mm, sendo quase 60% a mais em relação a 2008, e aproximadamente 32% foi interceptada pela floresta e 68% chegam à superfície do solo. O coeficiente de deflúvio foi de aproximadamente 48% da precipitação, sendo 52% perdidos por evapotranspiração. O fato de haver predomínio de intensidades de chuva de 0 a 5 mm.h-1 permite inferir que quase a totalidade das chuvas pode se infiltrar no solo já que Ksat a 0,15 m de profundidade geralmente está acima dos valores de intensidade de chuva. O que está de acordo com o baixo valor obtido no coeficiente de escoamento superficial. Todos os processos hidrológicos apresentaram baixas concentrações de nitrogênio inorgânico. O aporte de nitrogênio no sistema hidrográfico pela precipitação no ano de 2008 foi de 3,79 kg N ha-1 ano-1, e a perda via fluvial foi de 0,67 kg N ha-1 ano-1, gerando um ganho líquido de 3,12 kg N ha-1 ano-1. No ano de 2009 o ganho foi de 1,39 kg N ha-1 ano-1 de nitrogênio, com um aporte de 1,84 kg N ha-1 ano-1 e uma perda via fluvial de 0,45 kg N ha-1 ano-1. Com os resultados obtidos, podemos concluir que o escoamento de base foi à principal via hidrológica que compõe o deflúvio, e apesar da precipitação ter sido maior em 2009, as proporções de interceptação, escoamento superficial e evapotranspiração se mantiveram inalteradas. Em termos de nitrogênio, as baixas entradas e saídas monstraram que a microbacia possui ciclo de nitrogênio bastante conservativo. Com exceção do escoamento superficial e da transprecipitação, o nitrogênio orgânico predominou em relação ao inorgânico / The Atlantic rainforest is one of the most endangered ecosystems of our planet, this once huge forest area presents only 8% of its original distribution and need special attention in terms of the comprehension of its functioning as a mean to improve conservation goals. In this context, the present study contributes to increase the quantity of studies carried out in this region aimed to describe the hydrological functioning and the nitrogen dynamics of a small catchment covered by Atlantic rainforest sited on north coast of Sao Paulo State, Brazil. To reach these goals, hydrological processes such as surface runoff, groundwater, streamflow, precipitation, net precipitation, soil water storage at 0,15, 0,30, 0,50 and 0,90 m, water table fluctuations, were monitored during two years (2008 and 2009). Aiming to clarify soil hydrological processes the soil saturated hydraulic conductivity was measured in the field at the depths of water storage measurements using a constant head permeameter. In addition, a flow injection system was used to determine inorganic (N-NO3 - and N-NH4 +) concentrations in the water of these hydrological processes. For organic nitrogen calculations, total dissolved nitrogen was determined by Total Organic Carbon Analyser. For 2008, the annual precipitation (P) was 1716 mm, being 33% intercepted by the forest canopy. The remaining 67% reached the soil surface. The annual water yield (Q) was 681 mm and the runoff coefficient was 40% of annual rainfall being the rest, 1035 mm, lost as evapotranspiration. For 2009, annual precipitation was 2009, a value 60% higher than in 2008. Of this amount, 32% was intercepted by forest and 68% reached the forest floor. Runoff coefficient was 48% of annual rainfall and the difference between these processes was lost as evapotranspiration. The predominance of low intensity rainfall (0 5 mm h-1) provide basis to infer that most rainfall events infiltrate the soil because Ksat at 0,15 m always exceeds this rainfall rates. In this way, very low surface runoff coefficients were calculated from the plots. For nitrogen, the results of inorganic nitrogen concentrations showed very low values in all hydrological processes. The rainfall input of nitrogen in 2008 was 3,79 kg ha-1 yr-1 and output by streamflow was 0,67 kg ha-1 yr-1. Calculations show a net gain of 3,12 kg ha-1 yr-1. For 2009, the net gain was about 1,39 kg ha-1 yr-1. Annual rainfall input was estimated as 1,84 kg ha-1 yr-1 and nitrogen streamflow outputs was 0,45 kg ha-1 yr-1. From these results, the following conclusions can be drawn: (a) baseflow is the main source of water for the annual water yields. Despite the fact of higher annual precipitation in 2009, interception losses as well as surface runoff and evapotranspiration maintained the same values. For nitrogen, low deposition rates (inputs) as well as low outputs via streamflow demonstrate that the forest within the watershed presents a conservative nitrogen cycle. Except for net precipitation and surface runoff, organic nitrogen predominated against inorganic nitrogen
263

Superfícies de erosão do setor centro-oriental da Bacia do Rio Paracatu, no Estado de Minas Gerais / Erosion Surfaces in the central eastern sector of Paracatu river catchment, State of Minas Gerais

Mário Teixeira Rodrigues Bragança 03 May 2012 (has links)
A regularidade do relevo da bacia hidrográfica do rio Paracatu, inserida no Escudo Atlântico, preserva uma coluna estratigráfica em suas condições originais de deposição e com registros de movimentos crustais de pequena dimensão. Por isso, bucou-se associar a evolução da geomorfologia da bacia do rio Paracatu aos materiais e estrutura, na busca da compreensão da evolução do relevo da área; para tanto, foram consideradas as sucessões sedimentares, discordâncias e patamares erosivos, condição necessária para identificar e descrever padrões geomórficos regulares na paisagem. Revisão da bibliografia geológica e geomorfológica, manipulação da cartografia geológica e topográfica e sua integração e tratamento em SIG, a construção de perfis topográficos a partir de um modelo digital de terreno e campanhas de reconhecimento de campo nortearam os trabalhos, levando à identificação e descrição de quatro superfícies erosivas que registram as marcas da evolução geomorfológica regional: Superfície de Planaltos Tabulares, Superfície de Planaltos Tabulares com Vales Encaixados, Superfície de Planaltos Baixos com Pedimentos Ravinados e Vales Encaixados e Superfície da Depressão da Planície Fluvial do Rio Paracatu, ponto de convergência da reconstituição da história geomorfológica da área de estudo, resultando na composição de um mapa de superfícies de erosão. / The regularity of the relief of Paracatu Catchment inserted into Atlantic Shield, is preserved in weathering and erosion resistant rocky layers. It is organized in a stratigraphic column wich keeps its original conditions of deposition with recordings of small dimension crustal movements, allowing the ideal theoretical conditions for the study of erosion surfaces. To associate the evolution of geomorphology of Paracatu River Catchment to material and structure, looking for explanations to the preservation of erosion surfaces in the arrangement of sedimentary successions, unconformities and erosive plateaus were the conditions to identify and describe four surfaces wich record the regional morphological evolution: Tabular Plateau Surface, Tabular Plateau Surface with Dissected Valleys, Low Tableland with Ravined Pedments and Dissected Valleys Surface, and Paracatu River Fluvial Plain Depression Surface. A broad fieldwork through a general and regional approach, followed by an intense bibliographic review and manipulation of topographic and geologic maps and its manipulation in GIS, through a development of a Digital Terrain Model and many topographic profiles, allowed to describe the relief in suggesting the reconstitution of the geomorphological history of the study area, resulting in an erosion surfaces map. The origin of this erosion surfaces can be correlated to four tectonic cycles, that elevated the Brazilian Platform since the Cretaceous until Pleistocene, with drainage incision and dissection of the landscape.
264

Transport of organic chlorine through soil : A study of organic chlorine in soil water from a catchment in northern Sweden

Söderholm, Simon, Karlsson, Rebecka January 2008 (has links)
Chlorine is an element commonly found in the environment of our planet, in the atmosphere, the earth crust and the oceans. Chlorine occurs in two forms, inorganic chloride (Clin) and organically bound chlorine (Clorg), also called organochlorine. For a long time, the organic halogens (among them the organic chlorine) had been considered as produced only by human activities. However, the research of the recent decades suggests a considerably amount of naturally produced organic chlorine in soil and water. Through the research, a hypothesis have emerged, suggesting that there occur a formation of organic chlorine in the top soil layer where chloride is consuming, while the organic chlorine is degrading on deeper soil levels, causing a release of chloride. The study in this thesis attempts to explore the transportation of organic chlorine through soil. 49 soil water samples were collected at three transects, S04, S12 and S22, nearby a stream in northern Sweden and analysed for Clorg, using an AOX-analyser. The results suggest a decrease in concentrations of Clorg by soil depth for transects S04 and S12. The study also indicates that concentrations of Clorg are decreasing with increasing distance from the stream, where the highest mean concentration was found in the organic matter-rich riparian transect S04. Further conclusions are that the spring flood and changes in groundwater level may influence the concentrations of Clorg. / Ämnet klor är vanligt förekommande på vår planet och finns både i atmosfären, jordskorpan och världens oceaner. Klor uppträder i två olika former: oorganisk klorid (Clin) och organiskt bundet klor (Clorg). De organiska halogenerna (bland vilka organiskt klor ingår) har under lång tid ansetts härstamma från enbart antropogena källor. De senaste decenniernas forskning har dock tytt på en naturlig produktion av organiskt klor i mark och vatten. Genom denna forskning har en hypotes tagit form som föreslår en bildning av organiskt klor i de övre marklagren, där klorid binds, medan det i djupare marklager sker en nedbrytning av det organiska kloret vilket medför ett frigörande av klorid. Denna studie syftar till att studera transporten av organiskt klor genom mark. 49 stycken markvattenprover insamlades vid tre provpunkter (S04, S12 och S22) på ett avrinningsområde i norra Sverige och analyserades med hjälp av ett AOX-instrument. Resultaten tyder på en minskning av Clorg med ökande markdjup för provpunkterna S04 och S12. Studien visar även en minskning i koncentration av organiskt klor med ökande avstånd till vattendraget, där den högsta medelkoncentrationen återfanns i provpunkten S04 som ligger nära bäcken och är rik på organiskt material. Vidare slutsater är att vattenflödena under vårflod samt variasionen i grundvattennivå har en påverkan på koncentrationerna av Clorg.
265

Variable Specific Discharge and Its Influence on Mass Export of Carbon, Sulphur, Calcium and Magnesium in a Boreal Forest Catchment / Variabel specifik avrinning och dess påverkan på exporten av kol, svavel, kalcium och magnesium från ett avrinningområde i barrskogsbältet

Gärtner, Isabell January 2016 (has links)
Considerable research efforts are made in order to understand the global carbon cycle and how it will affect future climate change and vice versa. To be able to calculate the export of carbon from a certain area, discharge is one of the most important variables together with stream concentrations. Measuring discharge in every catchment would be impossible, as it is both time consuming and expensive. To come around these obstacles, the majority of studies on element export use known discharge data from gauging stations at a single catchment outlet and assumes the same discharge per unit area from nearby catchments, known as the assumption of uniform specific discharge. A few studies in recent years, have come to the conclusion that this questionable assumption can lead to large errors in estimated discharge volumes and it should therefore be reconsidered.This study aims to analyse how the export of elements changes if actual measured variable discharge is applied in comparison to uniform specific discharge. The results of this study shows that the assumption of uniform discharge leads to an overestimation of the export of dissolved organic carbon (DOC), sulphur, calcium and magnesium from forest-dominated catchments by up to 30%. At the same time this assumption leads to an underestimation of export from wetland-dominated catchments by up to 26% over a five year period. / Mycket av forskningen de senaste åren har handlat om framtida klimatförändringar och det globala kolkretsloppet och hur de båda påverkar varandra. För att göra tillförlitliga beräkningar av hur mycket kol ett område, i det här fallet ett barrskogsområde i norra Sverige, tillför vattendragen i närheten under en viss tid skulle det behöva göras vattenståndsmätningar och vattenanalyser vid varje vattendrag, men det skulle vara omöjligt eftersom det är för kostsamt och tidskrävande. För att ändå kunna göra uppskattningar av hur mycket kol, spårämnen och metaller som kommer från ett område, använder de flesta studier information om vattenstånd och ämneskoncentrationen i vattnet från mätningsstationer vid avrinningsområdets utlopp. Samma uppgifter används för att göra beräkningar för det stora området, som för mindre delområden i det. Under de senaste åren har ett antal studier kommit fram till att användandet av data som inte har tagits i direkt anslutning till ett avrinningsområde kan leda till stora fel och kanske borde undvikas.Den här uppsatsen har som syfte att analysera vilka skillnader som uppstår när avrinningsdata från olika delområden används istället för samma data för alla områden. Resultatet av denna studie visar att om man använder samma data för alla områden leder det till att exporten av kol, svavel, kalcium och magnesium från huvudsakligen skogsklädda områden överskattas med upp till 30% och underskattas från områden med mycket våtmarker med upp till 26%.
266

Caracterização pedológica, uso da terra e modelagem da perda de solo em áreas de encosta do rebordo do planalto do RS / Pedological characterization, land use and modeling of the soil in hillslope areas the plateau border of RS

Miguel, Pablo 25 February 2010 (has links)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The river catchment Vacacaí Mirim is located where the water reservoir that supplies part of the water needs of the city of Santa Maria is located in a hillslope area of plateau border Southern Rio Grande. In these hillslope areas, due to the combination of strong relief is rolling to hilly common occurrence of soils with variable depth, with the predominance of shallow soils. The objectives were to conduct a study of current use and the evolution of land use and demarcation of areas of risk or potentially susceptible to loss of soil from the Universal Soil Loss Equation (USLE). The soil survey of semi-detailed, characterize the different soil classes occurring in the region. Through techniques of GIS maps were generated from soil, slope, Permanent Preservation Areas (PPAs), land suitability and land use evolution from 1987 to 2009. Map was made usability and identified areas of land use conflicts. According to the soil survey over 50% of the area consists of Entisols and over 50% of the area has less ability, being only suitable for the protection of fauna and flora. For the second study, the topographic factor (LS) was generated from the digital elevation model (DEM), the rainfall-runoff erosivity factor (R) data through normal rainfall, erodibility factor (K) the composition particle size of each class of soil, and cover-management and support practice factor (CP) through field observations and tabulated values. About 74% of the area has soil losses ranging 1 to 2 t ha-1.yr-1. Only 3% of the area has a soil loss of more than 20 t ha-1.yr-1, and of these 3%, 1% shows soil loss exceeding 50 t ha-1.yr-1. For assessing the potential loss of soil, the topographic factor (LS) was the most strongly determined the pace of erosion followed by the factor use and cover-management and support practice factor (CP) and soil erodibility factor (K). The aid of the image of computer application Google Earth is a very important tool in the evaluation of occupation and land use in the study area. The data gathered through this methodology for the estimation of factor use and cover-management and support practice factor (CP) are reliable and the researcher can make a conference field for a possible better definition of the classes of land use. / A bacia hidrográfica do rio Vacacaí Mirim onde está situado o reservatório de água que abastece parte da necessidade de água da cidade de Santa Maria encontra-se em uma área de encosta do Rebordo do Planalto Sul-Riograndense. Nessas áreas de encosta, devido à combinação de relevo forte ondulado a montanhoso é comum a ocorrência de solos com profundidade variável, havendo o predomínio de solos rasos. Os objetivos do trabalho foram a realização de um estudo do uso atual e da evolução do uso das terras e a delimitação de áreas de risco ou potencialmente susceptíveis a perdas de solo, através da Equação Universal de Perda de Solo (EUPS). O levantamento de solos do tipo semi-detalhado, caracterizou as diferentes classes de solos que ocorrem na região. Através de técnicas de geoprocessamento foram gerados mapas de solos, declividade, Áreas de Preservação Permanente (APPs), aptidão agrícola e evolução de uso das terras de 1987 a 2009. Foi elaborado o mapa de adequação de uso e identificadas áreas com conflitos de uso. Segundo o levantamento de solo mais de 50% da área é formada por Neossolos Litólicos e mais de 50% da área apresenta aptidão inferior, sendo somente indicada para a preservação da fauna e da flora. Para o segundo estudo, o fator topográfico (LS) foi gerado a partir do Modelo Digital de Elevação (MDE), o fator erosividade da chuva (R) através de dados normais de precipitação, o fator erodibilidade do solo (K) através da composição granulométrica de cada classe de solo, e o fator uso e manejo e práticas conservacionistas (CP) por meio de observações no campo e valores tabelados. Cerca de 74% da área possui perdas de solos que variam de 1 a 2 t.ha-1.ano-1. Somente 3% da área apresenta uma perda de solo de mais de 20 t.ha- 1.ano-1 , sendo que desses 3%, 1% apresenta perda de solo superior a 50 t.ha-1.ano-1. Para a avaliação do Potencial de Perdas de solo, o fator topográfico (LS) foi o que mais fortemente determinou o ritmo dos processos erosivos seguido do fator uso e manejo e práticas conservacionistas (CP) e fator erodibilidade do solo (K). O auxílio da imagem do aplicativo computacional Google Earth foi uma ferramenta de extrema importância na avaliação da ocupação e uso das terras na área de estudo. Os dados levantados através dessa metodologia para a estimativa do fator uso e manejo e práticas conservacionistas (CP) são confiáveis e o pesquisador pode fazer uma conferência de campo para uma possível melhoria da definição das classes de uso da terra.
267

Institutional overlaps in water management in the Eerste River catchment

Nleya, Ndodana January 2005 (has links)
Magister Philosophiae (Integrated Water Resource Management) / In this minithesis I have investigated overlapping mandates as a source of management failure in water management in South Africa in general and Eerste River Catchment in particular. I analysed major legislation which deals with water management to find out how duties and responsibilities are apportioned in the various pieces of legislation. I also undertook an exercise of evaluating roles and responsibilities played by various organs of state in water management from national government, Provincial Government of the Western Cape through to local government, in this case the Municipality of Stellenbosch and the City of Cape Town. It emerged that there were a number of areas of overlap, ambiguously defined mandates, conflict and that these were impeding on decision making in water management. In order to test the framework built above, I then applied it in the Plankenbrug River, a tributary of the Eerste River. Through analysis of newspaper clippings over a period of 4 years I was able to reconstruct conflict over ill-defined mandates in the various aspects of the management of the catchment which showed that there were differences in roles of the different state organs operating in the catchment. Water management conflict emanated from lack of congruence in the various legislation and differences in the interpretation of legislation. The various state organs seem to be aware of the constitutional duty of cooperative government that engenders state organs to work co-operatively in order to meet their developmental mandates. It seems however that the state organs were merely interested to be seen to be in conformity with this duty more than actually solving the issue as this was seen as something to be tackled at a higher level. / South Africa
268

Interpreting Prehistoric Patterns: Site Catchment Analysis in the Upper Trinity River Basin of North Central Texas

Williams, Marikka Lin 12 1900 (has links)
Archaeologically site catchment analysis produces valuable information regarding prehistoric subsistence strategies and social organization. Incorporating archaeological data into catchment analyses is an effective strategy to develop regional models of prehistoric site selection and settlement patterns. Digital access to data permits the incorporation of multiple layers of information into the process of synthesizing regional archaeology and interpreting corresponding spatial patterning. GIS software provides a means to integrate digital environmental and archaeological data into an effective tool. Resultant environmental archaeology maps facilitate interpretive analysis. To fulfill the objectives of this thesis, GIS software is employed to construct site catchment areas for archaeological sites and to implement multivariate statistical analyses of physical and biological attributes of catchments in correlation with assemblage data from sites. Guided by ecological, anthropological and geographical theories hypotheses testing evaluates patterns of prehistoric socio-economic behavior. Analytical results are summarized in a model of prehistoric settlement patterns in North Central Texas.
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Modelagem hidrológica de uma microbacia florestada da Serra do Mar, SP, com o modelo TOPMODEL : simulação do comportamento hidrológico em função do corte raso / Modelling the hydrology at subtropical forest small catchment in the Serra do Mar, São Paulo, Brazil, using TOPMODEL : simulation of hydrology behavior subject to clear-cutting

Maurício Ranzini 26 June 2002 (has links)
Utilizou-se o modelo hidrológico TOPMODEL, baseado em aspectos físicos e topográficos, em uma das três microbacias do Laboratório de Hidrologia Florestal Eng. Agr. Walter Emmerich, do Instituto Florestal/SP. O laboratório localiza-se na Serra do Mar, junto às cabeceiras do rio Paraibuna, um dos formadores do rio Paraíba do Sul. O modelo usa um índice topográfico que indica as áreas de contribuição para o deflúvio da microbacia e permite simular a vazão e analisar o comportamento hidrológico da microbacia. A primeira parte do trabalho buscou determinar os valores iniciais dos parâmetros de calibração, testar a validade das premissas do modelo, e, principalmente, compreender melhor o funcionamento hidrológico da bacia D. Os resultados indicam uma eficiência maior para as simulações de eventos isolados do que para as de períodos longos. A simulação do comportamento hidrológico em função do corte raso mostrou uma diminuição do tempo de pico e um aumento significativo do volume de vazão simulado: de 17 a 44%, em comparação a bacia D coberta com floresta. Mostram, também, que de 7 a 93% do deflúvio é gerado a partir das áreas variáveis de afluência (A.V.A.). Recomenda-se que o corte raso seja evitado a qualquer custo. Caso seja necessário, as matas ciliares devem ser mantidas; onde elas não existem mais, devem ser recuperadas imediatamente. As áreas com agricultura ou pastagem devem utilizar as melhores técnicas de conservação do solo, de forma que as condições naturais de infiltração não sejam drasticamente alteradas. / A physically based semi-distributed model, TOPMODEL, has been applied to one catchment in Cunha, São Paulo, Brazil. The model uses a topographic index which highlights significant hydrological areas within the catchment. The model simulate streamflow and analyse the behaviour of the catchment. The first part of this paper concerns to the first values of calibration parameters, experiments the validity of the premisses of the model, and, mainly, tries to understand how does the hydrology of D catchment works. The results are more efficient on simulation of isolate events than on events of long period. The simulation of hydrology behaviour subject to clear-cutting has showed a diminution of the time of rise and a significant increase of streamflow simulated: from 17 to 44%, in comparaison to D forest catchment. They also show that from 7 to 93% of the streamflow is generated from saturated contributing areas (sources areas). It\'s advisable to avoid clear-cutting. If necessary, the riparian zone has to be preserved; and where they have been destroyed, they have to be recovered urgently. Agricultural lands or grasslands have to use the best management practices, in order to keep the natural conditions of infiltration.
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Développement d'un modèle hydrologique de colonne représentant l'interaction nappe - végétation - atmosphère et applications à l'échelle du bassin versant / Development of a soil column model for simulating the water table - vegetation - atmosphere interaction and applications to the catchment scale

Maquin, Mathilde 30 September 2016 (has links)
Dans le cadre de la modélisation climatique, la représentation du cycle de l'eau des surfaces continentales est primordiale. Actuellement, les "modèles de surface continentale" représentent l'évolution des flux d'eau verticaux dans des colonnes de sol de quelques mètres de profondeur et leur interaction avec l'atmosphère. En revanche, l'interaction avec les nappes de faible profondeur n'est pas prise en compte alors que leur présence influence fortement les flux d'évapotranspiration à l'échelle locale, et, en conséquence, le climat à l'échelle régionale. Une difficulté est que les zones où cette interaction apparaît relèvent d'une échelle inférieure à celle du maillage des modèles de surface continentale. L'objectif de cette thèse est de proposer un modèle qui permette de prendre en compte l'impact des nappes de faible profondeur sur les flux d'évapotranspiration pour les modélisations climatiques à l'échelle globale. La contrainte principale associée relève des temps de calculs, qui doivent être réduits pour permettre la réalisation de simulations sur de grandes échelles de temps et d'espace. Dans ce cadre, un nouveau modèle de colonne de sol est proposé. Une fonction de drainage imposée en bas de colonne permet de reproduire l'évolution temporelle du toit de la nappe, en interaction avec les processus d'infiltration et d'évapotranspiration. Le modèle est testé et validé sur des cas tests académiques simples dans un premier temps, puis sur le cas d'un bassin versant réel dans un second temps (bassin versant du Strengbach, en France). Enfin, une méthodologie basée sur ce modèle de colonne et permettant d'estimer les flux d'évapotranspiration en tenant compte de leur variabilité dans l'espace est introduite. Elle est appliquée à un bassin versant dont la superficie est proche de celle d'une maille classique des modèles de surface continentale (bassin versant du Little Washita, aux États-Unis). / The representation of the water cycle on land surfaces is essential for climate modeling. Nowadays, the "Land Surface Models" (LSMs) represent soil columns of a few meters deep and they simulate the temporal evolution of the vertical water flows and the interaction with the atmosphere. However, the interaction with a near-surface water table is not taken into account although it strongly influences the evapotranspiration fluxes at the local scale, and therefore the climate at the regional scale. This interaction, which occurs at a smaller scale than the grid scale of the LSMs, is difficult to model. The objective of this PhD is to propose a model that incorporates the impact of a near-surface water table on evapotranspiration fluxes for global climate models. The computation time of the model must be small enough to enable simulations at large spatial and temporal scales. In this context, a new soil column model is proposed with a drainage function that is imposed at the bottom of the column. This function aims at reproducing the temporal evolution of the water table level in interaction with both the infiltration and the evapotranspiration fluxes. The model is tested and validated on numerical experiments and on a real catchment (Strengbach, France). A methodology based on this column model is introduced to estimate the evapotranspiration fluxes taking into account their subgrid variability. This methodology is applied to a catchment whose area is similar to the one of a classic grid cell of LSMs (Little Washita, USA).

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