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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.
71

Integração de temas ambientais na caracterização da ecorregião aquática Xingu Tapajós, Amazônia Brasil

Silva, Ricardo Sierpe Vidal 19 April 2016 (has links)
Submitted by Biblioteca de Pós-Graduação em Geoquímica BGQ (bgq@ndc.uff.br) on 2016-04-19T17:51:13Z No. of bitstreams: 1 Dissertacao_Ricardo_Sierpe_2012.pdf: 8540575 bytes, checksum: 1b2ac4ff3c42abf36cc1a3c954a39998 (MD5) / Made available in DSpace on 2016-04-19T17:51:13Z (GMT). No. of bitstreams: 1 Dissertacao_Ricardo_Sierpe_2012.pdf: 8540575 bytes, checksum: 1b2ac4ff3c42abf36cc1a3c954a39998 (MD5) / Conselho Nacional de Desenvolvimento Científico e Tecnológico / Universidade Federal Fluminense. Instituto de Química. Programa de Pós-Graduação em Geociências-Geoquímica. Niterói, RJ / Esta dissertação foi realizada no âmbito da pesquisa Delineamento da Ecorregião Aquática Xingu-Tapajós – “AquaRios”, desenvolvida no Centro de Tecnologia Mineral – CETEM. A ecorregião aquática em foco está localizada integralmente na Amazônia Legal, sendo por sua vez um interflúvio dos rios Tapajós e Xingu, ambos afluentes da margem direita do rio Amazonas. A presente dissertação traz para a Geoquímica Ambiental a discussão sobre ecorregião aquática, bacia hidrográfica, meio ambiente, e suas relações com a hidrogeoquímica das águas fluviais por meio da análise espacial dos diferentes temas bióticos, abióticos e antrópicos individualizados em um conceito atual e oficial de recorte espacial para a gestão territorial, as Ottobacias, no caso presente Ottobacias de nível 4. O marco ordenador dos temas ambientais, ou seja, a ferramenta utilizada na integração de temas e processos relacionados foi a Equação Universal de Perdas de Solo – EUPS, calculada através de diversos procedimentos presentes no que atualmente é convencionado como Geotecnologia. O resultado obtido foi uma inovadora criação e distribuição geográfica dos clusters de Ottobacias evidenciando uma situação de degradação ambiental na ecorregião, especialmente nos setores nordeste, noroeste e sul provocado em grande parte pela destruição da cobertura vegetal original. De acordo com os dados coletados em campo essa situação reflete na hidrogeoquímica e na fauna aquática. O resultado desta dissertação fornece um subsídio consistente a ser utilizado na gestão dos recursos hídricos, essencialmente no tocante a qualidade e gestão de bacias hidrográficas na Amazônia / This dissertation was made by the research’s ambit Delineamento da Ecorregião Aquática Xingu-Tapajós – “AquaRios”, developed at the Centro de Tecnologia Mineral - CETEM. The aquatic ecoregion in focus is fully located in Legal Amazon, being an interfluve between the Tapajós and Xingu rivers, both tributaries of the right Amazon River’s side. This paper brings into the Environmental Geochemistry the discussion about aquatic ecoregion, watershed, environment, and its relations with the freshwater’s hydrogeochemistry by a spatial analysis of the different biotic, abiotic and anthropogenic themes individualized in a modern and official concept with a spatial look to territorial management, the Ottobacias, in this case level 4 Ottobacias. The originator mark of environmental issues, it means, the tool used in the themes’ integration and related processes was Universal Equation of Soil Loss calculated by several procedures present in what is currently agreed as Geotechnology. The result was an innovative creation and geographic distribution of Ottobacias clusters showing the situation of environmental degradation in ecoregion, especially in the northeast, northwest and south areas, caused mostly by the destruction of the original coverage vegetation. According to the collected data it reflects directly in the hydrogeochemistry and aquatic fauna. The result of this dissertation provides a consistent subsidy that is to be used in the water resources management, essentially with regard to the quality and Amazon’s watershed management
72

Návrh protierozních opatření v malém povodí / The desigm of the soil protection maesures in the small watershed

Skalická, Kristýna January 2015 (has links)
This diploma thesis is about water erosion. There are types of water erosion, consequences and ways how to reduce erosion. The second part describes and claculates soil loss in an area of Zasova and Zubri. For calculation is used programme ArcGis. Based on the resoults are suggested two ways of erosion kontrol measures. Their efficiency is proved in programme ArcGis and the resoults are compared.
73

Vliv změn krajiny na erozní a odtokové poměry / The influence of landscape changes on erosion and runoff

Uhrová, Jana Unknown Date (has links)
The aim of this thesis is to evaluate the influence of land use changes on erosion and runoff conditions. For the purpose of the evaluation, two catchments with different areas and pedological characteristics were selected (the catchment of the river Luha and the catchment of the Hubenov reservoir). In these catchments, a comparison of 26 selected land covers was conducted. The individual land covers were evaluated first in four seasons of the 1950s and 1990s, second according to the today's status of landscape by means of a detailed yearly evaluation conducted between 2002 and 2013, and third according to a land cover conceptual design. Analyses of not only land cover, but also geomorphological, pedological and hydrological conditions were carried out for both of the catchments by means of geographic information system (GIS) tools. The quantification of soil loss was performed by means of two methods – the method USLE with the use of ArcGIS program and the soil loss model WEPP. The crucial factor of the runoff evaluation of the preset end profiles with respect to the formation of concentrated runoffs and their catchment areas was the hydrological model DesQ-MAXQ. The selected land cover scenarios of the river Luha were then exposed to the conditions of a real rainfall that occurred in 2009 and that resulted in floods in the area. Furthermore, a rainfall-runoff model was created for this catchment area in HEC-HMS; the land cover scenarios were again subjected to the above-mentioned real rainfall. The land use changes of the catchment area of the reservoir Hubenov were assessed also with respect to the concentration of substances in the profiles studied.
74

Vliv uspořádání krajiny na erozní a odtokové poměry povodí / Influence of the landscape management on erosion and runoff conditions of the catchment

Hájek, Daniel January 2016 (has links)
Aim of this study is to evaluate the effects of landscape structure on soil erosion and runoff conditions of given area with help of digital elevation model and relevant GIS data. Analyses of soil erosion by water and runoff were processed for current conditions and several other variations. Based on this analyses and results was performed an evaluation of all model variations.
75

Experimentelle Untersuchungen zum Einfluss physikalischer Bodeneigenschaften auf die Rillenerosion

Hieke, Falk 29 January 2010 (has links)
Der Einfluss bodenspezifischer Größen auf die Rillenerosion wurde in Überströmungsversuchen in einem eigens dafür konstruiertem Kleingerinne untersucht. Die Neigung des 2 m langen und 0,1 m breiten Gerinnes wurde dafür zwischen 2, 4 und 6 % variiert. Im Gerinne wurden zum einen natürliche Böden, zum anderen künstliche, aus Schluff und Sand gemischte Substrate mit 0,060 l*s-1, 0,125 l*s-1 und 0,300 l*s-1 überströmt. Die Körnung der natürlichen Böden reichte von stark schluffig bis sandig-lehmig, die der künstlichen Substrate von stark schluffig bis sandig. Die künstlichen Substrate wiesen im Gegensatz zu den natürlichen Böden keine Aggregierung auf und waren frei von organischer Substanz. Zu Beginn der Versuche wird der Boden zunächst flächig überströmt. Währenddessen bilden sich Mikrorillen auf der Gerinnesohle aus. Selektiver Sedimenttransport bewirkt die Akkumulation der nicht transportablen Fraktion auf der Bodenoberfläche, wodurch sich Rippel bilden. Über den Rippeln formen sich stehende Wellen im Abfluss. Die stehenden Wellen erzeugen Sohlschubspannungsspitzen auf die Gerinnesohle, welche zu verstärkter lokaler Erosion, zur Ausbildung von Mikrodepressionen und im weiteren zur Entstehung von Rillenköpfen führen. Die Rillenköpfe wandern entgegen dem Gefälle und hinterlassen Rillen, in denen sich der Abfluss konzentriert. In den Rillen können weitere Rillenköpfe entstehen. Anhand des Beginns der Rillenerosion, der Rillenkopfneubildungsrate, dem Erosionsfortschritt der Rillenköpfe, der Bestandsdauer der Rillenköpfe und der Sedimentkonzentration im Abfluss kann das Phänomen „Rillenerosion“ erfasst und quantifiziert werden. Diese erosionsspezifischen Kennwerte zeigen sich dabei in Abhängigkeit von bodenspezifischen Größen, wie der Lagerungsdichte, der Korngrößenzusammensetzung sowie der Aggregatgrößenverteilung und –stabilität. Aus den Korrelationsanalysen zwischen den bodenspezifischen Größen und den spezifischen Kennwerten der Rillenerosion leiten sich empirische Beziehungen ab. Diese Beziehungen sind nicht-linearerer und nicht-stetiger Natur. Parallel zu den Versuchen im Kleingerinne wurden Überströmungs- und Beregnungsversuche in einem Großgerinne durchgeführt. Die Projektion der laborativen Ergebnisse des Kleingerinnes auf das naturnahere Großgerinne zeigte dabei Parallelen.
76

Mapeamento e análise da suscetibilidade à erosão pluvial na Unidade de Gerenciamento dos Recursos Hídricos do rio Aguapeí (UGRHI 20), no Estado de São Paulo, Brasil /

Ferreira, Edi Carlos January 2019 (has links)
Orientador: Isabel Cristina Moroz-Caccia Gouveia / Resumo: O presente trabalho tem como objetivo principal analisar a suscetibilidade aos processos erosivos laminares e lineares, identificando áreas mais críticas e seus impactos sobre os recursos hídricos na Unidade de Gerenciamento de Recursos Hídricos da Bacia Hidrográfica do Rio Aguapeí (UGRHI-20), localizada no oeste do Estado de São Paulo. Para determinar a suscetibilidade à erosão laminar utilizou-se a Equação Universal de Perda de Solo (EUPS), desenvolvida por Wischmeier e Smith (1976). Para a suscetibilidade à erosão linear utilizou-se a metodologia de Fragilidade Ambiental proposta por Ross (1994). Os resultados mostraram que na UGRHI-20, as estimativas de perda de solo por erosão laminar estão muito acima do recomendado pela FAO (1965) e por Wischmeier & Smith (1978), pois 73% da área se enquadra na classe indicativa “Alta” com valores entre 50 – 200 t.ha-1 ano -1. Em relação à erosão linear, a condição da UGRHI-20 é considerada crítica, pois apresenta 57% de sua área nível de fragilidade emergente forte. Diante de tais resultados, espera-se que esse trabalho possa subsidiar o planejamento ambiental desta bacia hidrográfica pelo poder público e principalmente por órgãos gestores. Para isso, serão entregues exemplares desse trabalho em meio digital para o Comitê de Bacias Hidrográficas dos Rios Aguapeí e Peixe (CBH-AP). / Abstract: The present work has as main objective to analyze the susceptibility to laminar and linear erosive processes, identifying the most critical areas and their impacts on water resources at the Aguapeí River Basin Water Resources Management Unit (UGRHI 20), located in the west of São Paulo. To determine susceptibility to laminar erosion, The Universal Soil Loss Equation (USLE) developed by Wischmeier and Smith (1976) was used. For susceptibility to linear erosion, the Environmental Fragility methodology proposed by Ross (1994) was used. The results showed that in the UGRHI-20 laminar erosion soil loss estimates are far above those recommended by FAO (1965) and Wischmeier & Smith (1978), as 73% of the area falls under the “High” indicative class with values between 50 – 200 t.ha-1year-1. Regarding linear erosion, the condition of UGRHI-20 is considered critical, as it presents 57% of its area strong emerging fragility level. Given these results, it is hoped that this work can subsidize the environmental planning of this watershed by the government and especially by management agencies. To this end, copies of this work will be delivered digitally to the Aguapeí and Peixe River Watershed Committee (CBH-AP). / Mestre
77

Soil erosion by water : Estimating soil loss and sediment yield in the southern half of Sweden by using the Revised Universal Soil Loss (RUSLE) model

Myr, Ella January 2021 (has links)
Soil erosion has been recognized as an increasing threat to the environment and humans worldwide as anthropogenic activities have accelerated the soil degradation rate. In Sweden, it is estimated that 15% of the arable land is affected by soil erosion, and studies have shown that fields in the south of Sweden lose a substantial amount of soil under certain weather conditions. However, few studies have investigated current soil erosion rates and sediment yield on a large scale, focusing on Sweden. Therefore, this study aimed to estimate the annual soil erosion for all erodible surfaces in the southern half of Sweden and calculate the sediment load emitted into adjacent seas. I here applied the RUSLE model, which is the most widely used soil erosion model worldwide. The model required secondary data of precipitation, soil properties, LULC, and topography.The findings showed that most erodible surfaces in the study area eroded less than 0.5 t ha-1y-1. However, it varied considerably in both space and time. The catchments on the western part of the study area had, in general, a higher mean value than watersheds on the eastern coast. The total sediment load entering the Baltic Sea was 123500 t y-1, while Skagerrak and Kattegat's load was approximately 20% higher. Higher soil erodibility, rainfall erosivity, and steeper slope gradient in these regions could partly explain the spatial pattern. Large temporal variabilities in rainfall erosivity indicated that soil erosion and sediment transportation mainly occurred during the summer. However, previous research suggests that other erosive processes have a more significant impact on soil erosion than rainfall. Thus, the RUSLE may not predict the full extent of soil erosion occurring in the study area. Nevertheless, since there is no previous large-scale estimate of soil erosion in Sweden, it provides insights into the potential risks and extent of rainfall-induced erosion.
78

Landslide Distribution and Susceptibility, Material Properties, and Soil Loss Estimates for the Drift Creek Watershed (Siletz River), Lincoln County, Oregon

Korte, David M. 18 July 2018 (has links)
No description available.
79

Integration of Analytical Models for Estimating Sediment Supply and Evaluation of Channel Stability

Zhou, Hong 04 August 2016 (has links)
No description available.
80

Diagnóstico de processos erosivos em solos agrícolas mediante análise de modelos numéricos do terreno

Rosa, Joel Zubek 10 August 2018 (has links)
Submitted by Angela Maria de Oliveira (amolivei@uepg.br) on 2018-11-26T20:27:20Z No. of bitstreams: 2 license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5) Joel Zubek.pdf: 7864320 bytes, checksum: f2e6f06e6ec1c27abd616c5e845d97f8 (MD5) / Made available in DSpace on 2018-11-26T20:27:20Z (GMT). No. of bitstreams: 2 license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5) Joel Zubek.pdf: 7864320 bytes, checksum: f2e6f06e6ec1c27abd616c5e845d97f8 (MD5) Previous issue date: 2018-08-10 / Entre os principais problemas relacionados à conservação ambiental em áreas agrícolas está a degradação dos solos por meio da erosão hídrica que ocasiona a remoção das camadas mais férteis de solo e o transporte de partículas de solo para as partes mais baixas do relevo, o que contribui para o assoreamento dos recursos hídricos. Portanto, o presente estudo teve como objetivo diagnosticar processos erosivos em uma área de produção agrícola localizada na Fazenda Escola Capão da Onça – FESCON – UEPG, mediante análise de dados obtidos por Sistema de Navegação Global por Satélite (Global Navigation Satellite System - GNSS) e Aeronaves Remotamente Pilotadas (Remotely Piloted Aircraft - RPA). Para a realização do trabalho foi implantada uma grade regular com pontos de 45 x 45 metros de distância, totalizando 140 pontos em uma área de aproximadamente 26 hectares. Foram realizados georreferenciamento dos pontos da grade regular por meio de receptores de sinal GNSS Geodésico pós-processado e a coleta de atributos do solo (textura do solo). Os dados de textura do solo levantados na grade regular proporcionaram gerar modelos para o cálculo do fator de erodibilidade do solo para área de estudo. Com os valores altimétricos das coordenadas levantadas nos pontos da grade regular foi possível avaliar a precisão vertical de Modelos Numéricos do Terreno - MNT gerados por meio de dados obtidos com RPA. Foram avaliados os modelos gerados com dados obtidos por meio de equipamentos de RPA de asa fixa e multirotor com a distribuição de diferentes números de pontos de controle e sem pontos de controle. Mediante a análise estatística aplicada em relação entre a dispersão das diferenças altimétricas geradas nos MNT e os pontos da grade regular usados como referência, o MNT gerado com os dados de RPA asa fixa com pontos de controle apresentou o melhor resultado. Diante da constatação do melhor MNT foi modelado o fator topográfico para a área de estudo. A utilização de Sistema de Informação Geográfica - SIG proporcionou integrar todos os dados em um único ambiente computacional; gerar modelos por meio de interpolação; analisar a precisão dos modelos; implementar as equações para o cálculo dos fatores de erodibilidade e topográfico e também a Equação Universal de Perda de Solo Revisada (Revised Universal Soil Loss Equation – RUSLE); além das representações das informações. O resultado obtido com o modelo gerado mediante o cálculo da RUSLE apresentou a estimativa que mais de 70 % da área de estudo está com baixa suscetibilidade à erosão ou ligeira perda de solo. O restante da área de estudo apresentou perda de solos acima de 10 tonelada/ha.ano, indicando média e alta suscetibilidade à erosão. / Among the major problems related to environmental conservation in agricultural areas is soil degradation through water erosion, which causes the removal of the most fertile soil layers and the transport of soil particles to the lower parts of the relief, which contributes to the silting up of water resources. Therefore, the present study aimed to diagnose erosive processes in an area of agricultural production located at Fazenda Escola Capão da Onça - FESCON - UEPG, by analyzing data obtained by the Global Navigation Satellite System (GNSS) and Remotely Piloted Aircraft (RPA).For the accomplishment of the work a regular grid with points of 45 x 45 meters of distance was implanted, totaling 140 points in an area of approximately 26 hectares. Georeferencing of the regular grid points was carried out by means of post-processed GNSS signal receivers and the soil attributes collection (soil texture). The soil texture data collected in the regular grid provided the model for calculating the soil erodibility factor for the study area. With the altimetric values of the coordinates raised at the points of the regular grid it was possible to evaluate the vertical accuracy of Numerical Terrain Models generated through data obtained with RPA. The models generated with data obtained by means of fixed-wing and multirotor RPA equipment with the distribution of different numbers of control points and without control points were evaluated. by means of the statistical analysis applied in relation between the dispersion of the altimetric differences generated in the Numerical Terrain Model and the points of the regular grid used as reference, the Numerical Terrain Model generated with the fixed wing RPA data with control points presented the best result. In view of the finding of the best NTM, the topographic factor was modeled for the study area. The use of Geographic Information System GIS provided to integrate all the data in a unique computational environment; generate models through interpolation; analyze the accuracy of the models; implement the equations for the calculation of the erodibility and topographic factors and also the Revised Universal Soil Loss Equation (RUSLE); beyond the representations of the information. The result obtained with the model generated by RUSLE calculation showed that more than 70% of the study area is low susceptibility to erosion or slight soil loss. The rest of the study area presented soil loss above 10 ton / ha.year, indicating medium and high susceptibility to erosion.

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