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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.
221

Problematika zasakování odpadních vod do malých povodí / Artificial recharge of watewater in small catchments

Pleskotová, Nikola January 2014 (has links)
The main objective of the thesis is to study artificial wastewater recharge in the area of Řevničov and reassessment of related problems such as groundwater chemical changes, colmatage, and unfavorable legislation in the Czech Republic. Individual chapters describe the experience with the above mentioned topic in the Czech Republic, but classifies it into the global context. The major part of the thesis focuses on the assessment of the qualitative and quantitative impacts of wastewater artificial recharge in the geological environment. These conclusions are drawn from monitoring changes of groundwater quality, which are controlled on the network of monitoring boreholes in the Řevničov experimental catchment. The natural attenuation of geological environment has considerable impact to final composition of contaminated water, which is compared to legal limits of underground and potable water in Czech Republic. In the research area several tracing tests were also applied, with the aim of proving the expected flow of wastewater into monitoring borehole. The obtained data specify the situation in the area of interest, or may serve as a source of information for future studies dealing with similar topics. Powered by TCPDF (www.tcpdf.org)
222

Extremita odtoku v povodí horní Lužnice / Runoff extremity in the Upper Lužnice catchment area

Musil, Jan January 2015 (has links)
Thesis subject is the evaluation of runoff and flood regime of rivers Lužnice and Skřemelice at the closing profiles just before their confluences. The results are compared with findings from the profile Pilař, which were published in the past by other authors. More attention is paid to the evaluation of the hydrological year 2013 and in detail is described the flood in June of the same year. Daily flow data from the years 1971 - 2014 were used for evaluating of runoff conditions. The assessment of the runoff regime in terms of daily, monthly and annual flows were compared with the runoff regime in Pilař gauge station. The source regions with dominating influence on the resulting runoff were discovered. Analysis of the flood regime confirmed that spring floods in Lužnice came mainly from upland and hilly parts of catchment and large summer floods have main source area in the catchment of Lužnice river itself, before the confluence of the Lužnice river and Skřemelic river. When assessing flood in 2013, the main source areas of flood flows that hit Lužnice river basin were founded. The flood extremity was compared in each closing profiles.
223

Ecotoxicological assessment of the impact of paper and pulp effluent on the lower Thukela River catchment, KwaZulu-Natal, South Africa and the toxicological assessment of similar effluent from two other mills

16 March 2010 (has links)
M.Sc. / The lower Thukela River catchment supports the highly industrialised Mandini/Sundumbili Industrial Complex, which in turn supports Tugela Rail, a textile factory, a vegetable-oil factory, as well as the Sundumbili Sewerage Treatment works. All of these industries release their wastes into the Mandini River that leads into the lower Thukela River. Another major potential impacting factor on the lower Thukela River is the Sappi Tugela pulp and paper mill that has both abstraction and discharge points in the same region. In 2004 the Department of Water Affairs and Forestry completed a comprehensive Reserve Determination study for the Thukela River. Upon reviewing the results it was clear that many of the variables assessed were of low confidence or there was not sufficient data collected within the region of the Mandini and Thukela River confluence and further downstream (Resource Unit K). Therefore the previous studies were not able to determine the degree to which the industries in the lower Thukela system impacted upon the integrity of the system. The aim of this study was therefore to assess the contributing impacts of the Tugela pulp and paper mill and other industrial activities on the ecological integrity of the lower Thukela River. This was done by through a toxicity assessment of the potential impacts of effluent and wastewater using the Direct Estimation of Ecological Effect Potential (DEEEP) methodologies. The toxicity of pulp and paper effluent from the Thukela mill and the receiving water body was compared to effluents from two other mills (Stanger and Ngodwana), assessing the water quality in relation to the input of different industrial effluents in the lower Thukela River. The general integrity of the lower Thukela River in relation to the input of different industrial effluents was assessed using the Habitat Quality Index (HQI), Habitat Assessment Index (HAI), macroinvertebrate and fish population studies. These studies were integrated to derive the Ecostatus of the lower Thukela River using the Macro-invertebrate and Fish Response Assessment Indices (MIRAI and FAII respectively). The toxicity testing (DEEEP) showed the paper mill effluent in the Mandini River was the least hazardous whilst Ngodwana effluent showed the highest potential to elicit a harmful impact on the receiving water body. The latter effluent displayed the highest LC50 values for the fish and the Daphnia toxicity tests, as well as an extremely high base-pair substitution mutagen activity. Toxicity was also found in algae at 100% raw effluent exposure. Tugela and Stanger mill effluent samples were very similar in their toxicity, except that Stanger effluent showed greater mutagenicity potential with exceptionally high values of revertants. The Tugela effluent samples showed no concerning levels of mutagenicity. The fish showed lower levels of response to the Tugela sample when compared to the Stanger sample. Thus comparatively the Thukela system is regarded to be the least at risk with regards to effluent discharge into the receiving water body. The lower Thukela River integrity assessment showed a sharp increase in temperature below the discharge point of the pulp and paper mill effluent. This was attributed to the excessive temperatures recorded in the pulp and paper effluent itself. There was further decrease in dissolved oxygen, which was due a combination of the industrial waste water in the Mandini River and the pulp and paper effluent. The increased organic content in the sediments of the lowest site situated downstream (TR5) is a combination of both reduced velocity of the stream flow entering the upper reaches of the estuary as well as increased organic material entering the river via the pulp and paper effluent and the Mandini River above TR3-D. This was accompanied by increased contribution of fine particle size sediments to the overall sediment composition. Habitat conditions were near natural at sites upstream of the Mandini River and effluent discharge confluences with the Thukela River. The exception was at TR1 as the weir results in unnatural inundation of biotopes upstream. The habitat conditions around the confluences of the Mandini River and pulp and paper mill effluent discharge are diminished with a recovery noted further downstream at TR4 and TR5. Invertebrate assessment shows the upstream sites to be natural, while the impact sites were largely to seriously modified. Once again the downstream sites (TR4 and TR5) show an improvement to recover to a moderately modified state. The fish assessment also shows a decrease in the FAII score below the impacts when compared to the integrity above the impacts. However these results are of low confidence due to insufficient sampling effort as only electronarcosis, seine and cast nets were used. The Ecoclassification assessment indicated a clear decrease in Ecostatus between the sites that are upstream of the impacts caused by the industrial effluent from the Mandini River and the pulp and paper mill effluent from the effluent discharge stream. The MIRAI also clearly indicated that the major impacts are caused by the combination of the Mandini River and the pulp and paper effluent. However there was a recovery in the river further downstream from the impacts.
224

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

Bragança, Mário Teixeira Rodrigues 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.
225

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

Ranzini, Maurício 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.
226

Balanço de água e de nitrogênio em uma microbacia coberta por pastagem no litoral norte do Estado de São Paulo / Nitrogen and water budget of a small catchment covered by pasture in the north coast of Sao Paulo State, Brazil

Salemi, Luiz Felippe 16 June 2009 (has links)
A Mata Atlântica é o bioma mais ameaçado do Brasil. Sua degradação substancial ocorreu desde a chegada dos europeus ao país por meio da mudança de uso solo e pela exploração da floresta. No entanto, pouco se sabe a respeito das conseqüências hidrológicas e biogeoquímicas da mudança de uso do solo nos domínios do referido ecossistema. Neste contexto, as microbacias hidrográficas têm sido objeto de muitos estudos devido sua alta sensibilidade aos processos hidrológicos e biogeoquímicos ocorrentes dentro delas. No presente estudo, calculou-se o balanço hídrico anual de uma microbacia coberta por pastagem na região do litoral norte do Estado de São Paulo. Essa bacia originalmente era coberta por floresta ombrófila densa. Em adição, amostrou-se água do escoamento do riacho, escoamento superficial, solução do solo (30, 50 e 90 cm de profundidade), água subterrânea, e precipitação de 05/12/2007 à 04/12/2008 para a análise de nitrogênio inorgânico. O conteúdo de nitrogênio (N-NH4 + e N-NO3 -) foi determinado por análise por injeção em fluxo (FIA). Com o intuito de elucidar os processos hidrológicos que geram escoamento direto, mediu-se a condutividade hidráulica do solo em condição de saturação a 15, 30, 50 e 90 cm com um permeâmetro de carga constante. Como resultados, foi obtido que o sistema hidrográfico possui evapotranspiração, calculada para o período de estudo, de 697 mm (precipitação anual e deflúvio anual, respectivamente, de 1433 mm e 736 mm); por meio da curva de duração de fluxo, o escoamento de base foi inferida como a via hidrológica com maior contribuição ao deflúvio anual. O escoamento superficial é pouco expressivo devido ao fato que 77% dos eventos de chuva se enquadram na classe de intensidade de 0-5 mm h-1 que está abaixo da condutividade hidráulica do solo em condição de saturação a 15 cm de profundidade (22 mm h-1). O baixo coeficiente de escoamento superficial (0,01) obtido em parcelas corrobora essa assertiva. Ademais, como predominam chuvas de baixa intensidade, apesar de haver degradação física do solo, não espera-se diferenças expressivas na produção de escoamento direto. A maioria das amostras tiveram suas concentrações abaixo do limite de detecção (0,71 µM e 0,35 µM para N-NH4 + e N-NO3 - respectivamente). Na maioria dos compartimentos e processos hidrológicos o amônio predominou em relação ao nitrato. Para a solução do solo, percebe-se que há pulsos de nitrogênio inorgânico quando o solo se torna menos úmido. Nota-se pelo balanço de nitrogênio inorgânico associado à água que a microbacia possui um ganho líquido (0,95 kg N ha-1 ano-1) de nitrogênio já que o influxo foi equivalente a 1,10 kg N ha-1 ano-1 e o efluxo foi de 0,15 kg N ha-1 ano-1. Em relação aos estudos semelhantes conduzidos em florestas e pastagens, percebe-se que a pastagem é muito mais pobre que as florestas e ainda mais pobre do que muitas pastagens no tocante ao nitrogênio inorgânico o que provavelmente decorre do método de a mudança de uso do solo, da ausência de fertilização, da alta taxa de lotação e da idade da mesma. / The Atlantic forest is the most endangered biome of Brazil. Its significant destruction has taken place since the arrival of Europeans settlers in the country. These Europeans destructed most part of it by changing land use and also due to forest exploitation. In this way, very little information is known about the hydrological and biogeochemical consequences of land use change in the region of this once huge ecosystem. In this context, small catchments have being used to assess these cited consequences of land use change due to their high sensitivity of hydrological and biogeochemical process that occur within them. In the present study, the annual water budget of a small watershed covered by grass (pasture) located in the north coast of the Sao Paulo State, Brazil has been calculated. Additionally, (1) stream water, (2) surface runoff, (3) soil solution (at 30, 50 and 90 cm depth), (4) groundwater and (5) precipitation were sampled weekly and, afterwards, due to analytical reasons, (2) and (3) were sampled biweekly, to determine the concentration of inorganic nitrogen (N-NH4 + and N-NO3 -) by FIA. Moreover, aiming to clarify the possible hydrological process of stormflow, the soil saturated hydraulic conductivity was measured at various depths (15, 30, 50 and 90 cm). The results obtained are: the evapotranspiration of the watershed vegetation, calculated for the study period, was 697 mm (annual precipitation and annual water yield, respectively, de 1433 mm e 736 mm). By the flow duration curve, the baseflow was inferred as the main hydrological pathway that contributes to the total annual water yield. The surface runoff was not very expressive for the reason that 77% of rain intensity was sited in the class of 0 - 5 mm h-1 that is lower than the median of soil saturated hydraulic conductivity at 15 cm depth (22 mm h-1). The low runoff coefficient (0,01) calculated from the runoff plots assures this result. Although soil physical degradation is present, it is not expected an expressive increment of direct runoff generation for the reason that low intensity rainfall predominates and does not exceed Ksat at 15 cm. Little inorganic nitrogen is found in the hydrological processes and pools. The majority of the samples had their inorganic nitrogen concentration below detection limits (0,71 µM e 0,35 µM for N-NH4 + e N-NO3 - respectively). In most pools and hydrological pathways the ammonium predominates against nitrate. For soil solution, it is notable that more inorganic nitrogen was found when the soil gets less wet. The observation of inorganic nitrogen balance dissolved in the water of rain and streamflow exhibits a net gain (0,95 kg N ha-1 year-1) of inorganic nitrogen because the input was 1,10 kg N ha-1 year-1 and the output was 0,15 kg N ha-1 year-1. If the results of nitrogen in the pools are compared to other similar catchment studies with land uses of forest and also pasture in Brazil and elsewhere, it is possible to conclude that the pasture presented here is poorer than forests and even some pastures. This fact may be a consequence of the land use clearing method, the lack of fertilization, the high stocking rates and also due to the pasture age.
227

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

Groppo, Juliano Daniel 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
228

Der Siedlungs- und Bestattungsplatz Nortmoorer Hammrich / Untersuchungen zur Besiedlungsgeschichte des Landkreises Leer (Ostfriesland). Römische Kaiserzeit bis Frühmittelalter. / The Nortmoorer Hammrich as a Settlement and Burial Site / Studies in the History of Settlement of Leer County (East Frisia, Germany). Roman Iron Age to early Middle Ages.

Rosenplänter, Petra 30 July 2014 (has links)
No description available.
229

Avgränsningsmetodens betydelse för hydraulisk modellering av spill- och dagvattennät / The effects of delineation metods on hydraulic modelling of wastewater networks

Johansson, David January 2019 (has links)
Metoden för att avgränsa modellområdet i delavrinningsområden med homogena hydrologiska parametrar inför hydrauliska ledningsnätssimuleringar kan vara tidsödande. Olika metoder och tillvägagångssätt finns att tillgå, men kunskapen om hur valet av avgränsningsmetod påverkar simuleringsresultaten är begränsad.   I examensarbetet undersöktes hur fyra enkla avgränsningsmetoder, i jämförelse med två detaljerade metoder, påverkade en hydraulisk simulering av en regnhändelse på sex olika modelluppsättningar av spill- och dagvattennät. De detaljerade metoderna byggde på information om markhöjder i kombination med byggnaders placering, medan de enklare metoderna byggde på information om markhöjder respektive Thiessenpolygoner. Avgränsningsmetoderna testades för en dagvattenmodell, en kombinerad spill- och dagvattenmodell, och fyra spillvattenmodeller. Alla modellparametrar förutom de associerade med delavrinningsområdena (bidragande yta, koncentrationstid) hölls konstanta medan en regnhändelse med återkomsttid tio år och en maximal regnintensitet av 22,8 µm/s (82.1 mm/h) simulerades för varje avgränsningsmetod och modelluppsättning.    De olika metoderna gav upphov till skillnader i simulerat maximalt vattendjup i modelluppsättningarnas brunnar. De enklare metoderna tenderade att underskatta de simulerade vattendjupen och avvikelsen mot de detaljerade metoderna översteg 0,1 m, vilket utgjort en gräns för när avvikelsen får praktisk betydelse. Fler avvikelser erhölls uppströms i ledningsnätet och för modelluppsättningar med större avrinningsbildning. Inga entydigt upprepande förhållanden mellan metodernas påverkan på simuleringsresultaten mellan modelluppsättningarna fanns, varvid modellområdesegenskaper tros påverka effekten av vald avgränsningsmetod. Resultaten indikerade att det kan vara mer motiverat att använda enklare avgränsningsmetoder för spillvattenmodeller i förortsmiljö än för dagvattenmodeller i stadsmiljö, samt att metoder baserat på Thiessenpolygoner ger bättre överensstämmelse mot detaljerade metoder än de topografibaserade. / The method of delineating a model into sub-catchments with homogenous hydrological parameters, before performing hydraulic simulations, can be tedious work. Different approaches and methods for this purpose exist, but the understanding for how the choice of delineation method affects the modeling process and in the end the simulation results is limited.    This thesis explored how four simplified delineation methods, in comparison with two detailed methods, affected hydraulic simulation of a rain event on six different model set ups. The detailed methods were based on terrain analysis and property boundaries. The simplified methods were composed of twomethods based on terrain analysis of elevation models, and two methods based on Thiessen polygons. The delineation methods were applied on one stormwater model, one combined storm- and wastewater model, and on four wastewater models. All model parameters except for those associated with the sub-catchments (time of concentration, imperviousness) were kept constant as a scenario of a rain event with a return time period of 10 years and maximum intensity of 22.8 µm/s (82.1 mm/h) were simulated for every delineation method and model set up.   The different methods resulted in differences in simulated maximal water depth in the modelled manholes. The simplified methods tended to underestimate the water depth. Additionally, the deviation from the detailed methods exceeded 0.1m, which is a threshold value for when the deviations will be of practical importance. Greater deviations occurred upstream in the sewer system and for models with greater runoff volume. No unambiguous patterns were found between the methods and the model setups. Hence, the delineation methods cannot by themselves explain the observed deviation in the simulated water depths. The results indicate that it is more suitable to apply a simple method on a sewage model in a suburban area, than for a stormwater model in an urban area. In addition, the simplified methods based on Thiessen polygons showed more agreement with the detailed methods than the simple methods based on terrain analysis.
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THE IMPACT OF THE SCALE OF MAPPING ON SOIL MAP QUALITY

Eldridge, Simon Michael, n/a January 1997 (has links)
It is generally assumed that increased map precision (ie map unit homogeneity) and map purity (map unit accuracy) should result from increasing the scale of mapping of the soil resource, since it should enable a more intricate breakdown of the landscape into landform facet based units. This study compared the predictive success of a 1:10K scale soil association map with the 1:25K and 1:lOOK scale soil landscape maps within the Birrigai area of the Paddy's river catchment, south west of Canberra, A.C.T. The 1:25K and the 1:lOOK scale soil landscape maps were also evaluated in a second larger evaluation area in the Paddy's river catchment which allowed more of the larger soil landscape map units to be evaluated. The 1:25K scale soil map was produced by another author for the A.C.T Government, and was surveyed at a substantially lower survey intensity than that for the 1:lOOK and 1:10K scale soil maps (ie only 0.05 observation sites / cm2 of published map). These maps were evaluated using a set of randomly located independent evaluation sites in each evaluation area, and from these calculating and comparing standard Marsman & de Gruijter(1986) measures of Map Purity. The strength of soil-landscape relationships within this catchment were determined from a Fixed One Way Analysis of Variance, and from more simplistic graphical comparisons of the means and standard deviations of the discrete soil data within these landform based map units. Soil-landscape relationships for the Nominal scale soil data (ie class type data) were evaluated by comparing the Marsman & de Gruijter(1986) Homogeneity index ratings among the soil map units. Intensive survey traverses were also carried out in selected soil landscapes to further evaluate the strength of soil landscapes present. The results revealed obvious improvements in map quality associated with increasing map scale from 1:100,000 to 1:10,000, and these included increases in the predictive success (Map Purity), reductions in the extent of map unit impurities, and planning advantages associated with having individual land facets delineated on the 1:10,000 scale map. The respectable purity ratings achieved by the 1:100,000 scale soil landscape map (ie average purity rating of 63%) was largely attributed to the flexibility of the "soil material" approach to soil landscape mapping. The relatively poor performance of the 1:25K consultancy soil landscape map demonstrated the fact that; any benefit gained from the improved intricacy in the representation of map unit delineation's with increased mapping scale, will be drastically reduced if it is not matched by an associated increase in the intensity of field investigations. Evaluations of the soil-landscape relationships found that the land facets of the Paddy's river catchment generally failed to delineate areas that were both uniform and unique in respect of their soil properties. Soil-landscape relationships were instead found to be quite complex, applying to only certain land facets, and in regards to only certain soil properties. Soil maps with units based on landsurface features were recommended on the basis of the importance of other landscape factors other than soils to land capability ratings, as well as on the useability of such maps. This study recommended the adoption of a" >2 detailed soil profile observations / land facet in each map unit" mapping standard to ensure a reasonable estimate of the variability and modal soil conditions present, as well as a reliable confirmation of the perceived soil-landscape relationships. The error usually associated with small scale mapping was effectively reduced by rapid ground truthing, involving driving along the major roads dissecting the map area and making brief observations of soil exposures on road batters, despite the bias of the road network making such mapping improvements uneven across the map. The major point to come from this study was the re-emphasising of the point that soil spatial variability has to be accepted as a "real landscape attribute" which needs to be accurately described and communicated to land users, and must not be considered as some sort of soil mapping failure. The fact that individual facets of the landscape rarely coincide with unique pockets of uniform and unique soils and soil properties must be considered simply an on the ground reality of nature, and not some mapping failure. It was thought that since other landscape factors (eg hillslope gradient) most often dominate the determination of land use suitability and capability, it is better to effectively describe the range and modal state of the soil conditions within such facets, then to attempt to extrapolate possible soil boundaries using geostatistical techniques which cut across such land facets, and mayor may not correlate with real groupings of soil properties, depending on the spatial resolution of the soil variability distribution in the landscape. Even so the results of this investigation do put the validity of the physiographic terrain class mapping model as a predictor of soil traits under question, at least for the more complex landscape settings.

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