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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

Sistemas de cultivo da cultura do fumo com ênfase às práticas de manejo e conservação do solo / Tillage systems of the tobacco crop with emphasis tho the management of the practices and soil conservation

Pellegrini, André 23 February 2006 (has links)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Soil management systems with minimum tillage and mulch are predominant in agriculture of Southern of Brazil. No-tillage for tobacco crop is not common and restricted to isolated places and only for some farmers that, through empiric tests and adaptation of equipments, search for soil preservation and increased yield. The objective of this work was study the main soil management systems for tobacco crop and possibilities of changing the traditional system of tobacco cropping, with emphasis on practices of soil management and conservation to maintain the levels of yield and decrease the environmental impacts. Six treatments, in a completely randomized blocks design with three replicates, were installed: PC conventional till; CMP - minimum tillage rest; CMA - minimum tillage oat; PDcC no-tillage with camalhão; PDcCC no-tillage with consolidated camalhão; PDsC no-tillage without camalhão. The experiment was installed in a watershed, located in Agudo-RS city, in the agricultural year of 2004, in a Leptosol. The maim physical parameters were soil moisture, measured with a time domain reflectometer (TDR), in the depths of 0-0,06, 0,06-0,12 and 0,12-0,18 m, and soil temperature in the depth of 0,05 m, measured with datalogger and termopars, both during 87 days in the growth cycle; total porosity, macroporosity, microporosity, bulk density and soil water retention curve (CRA), determined in the depths of 0-0,06, 0,06-0,12, 0,12-0,18 and 0,18-0,24 m, 30 days after transplantion (DAT) and on 135 DAT, except for CRA, in the depths of 0-0,06 and 0,06-0,12 m; water and soil loss by runoff, determined for eight rain events, in two blocks, with on area of 1.2 m2 of collection; potassium and phosphorus, soluble and total were determined for seven rain events; the root system, the distribution in the cultural profile, nutrients availability in the exploration area, dry mass for soil volume and maximum depth of roots were determined; mechanical resistance of soil was determined with a manual penetrometer to verify the depth of the root impediment; measures of the plants included the leaf area, determination of plant height, number of leaves and yield for hectare. The conservation managements reduced soil and water losses, providing smaller amplitude in the daily temperature variation, larges soil moisture, but the yield was smaller than PDsC. This result for the PDsC was directly influenced by the shallower roots depth, which was a consequence of several factors, such as: presence of impediment layer; absence of ridge; nutrients in the surface and favorable initial conditions of soil temperature and moisture. However, there was great interaction among factors, turning complex the explanation of the results obtained; therefore, factors such as nutrients in the surface favored the losses of P and K soluble, decreasing their availability to plants; the impediment layer reduced the volume of soil explored by the roots and the ability for water storage, whereas the management systems PDcCC and PDsC were outside the upper or lower limit of water availability, in the layer of 0 to 0,06 m, for about 15 days. / Sistemas de manejos do solo com o mínimo de revolvimento e com palha em superfície predominam na maioria dos cultivos agrícolas, no Sul do Brasil. A utilização do plantio direto na cultura do fumo está sendo iniciada, mas restrita a locais isolados e a alguns agricultores, que, via testes empíricos e adaptação de equipamentos, buscam preservar o solo e aumentar a produtividade. O objetivo deste trabalho foi estudar os principais sistemas de manejo do solo para a cultura do fumo e as possibilidades de mudança no sistema tradicional de cultivo de fumo, com ênfase às práticas de manejo e conservação do solo, mantendo os níveis de produtividade e diminuindo os impactos ambientais. O delineamento experimental foi blocos ao acaso com três repetições e seis tratamentos, sendo eles: PC - preparo convencional; CMP - cultivo mínimo pousio; CMA - cultivo mínimo aveia; PDcC - plantio direto com camalhão; PDcCC - plantio direto com camalhão consolidado; PDsC - plantio direto sem camalhão. O experimento foi implantado em uma microbacia hidrográfica, localizada no município de Agudo-RS, no ano agrícola de 2004, sobre em um Neossolo litólico eutrófico típico. Os principais avaliadores físicos foram umidade volumétrica do solo, medida com reflectômetro de domínio de tempo (TDR), nas profundidades de 0-0,06, 0,06-0,12 e 0,12-0,18 m, e temperatura do solo na profundidade de 0,05 m medida com datalogger e termopares, ambas durante 87 dias no período de crescimento; porosidade total, macroporosidade, microporosidade, densidade do solo e curva de retenção de água (CRA), realizadas nas profundidades de 0-0,06, 0,06-0,12, 0,12-0,18 e 0,18-0,24 m aos 30 dias após transplante (DAT) e aos 135 DAT, exceto CRA, nas profundidades de 0-0,06 e 0,06-0,12 m; perda de água e solo pelo escoamento superficial, determinados em oito chuvas, em dois blocos, com uma área de coleta de 1,2 m2; fósforo e potássio solúvel e total, em sete chuvas; no sistema radicular foram determinados a distribuição no perfil cultural, disponibilidade de nutrientes na região de exploração, massa seca por volume de solo e profundidade máxima das raízes; a resistência mecânica do solo determinada com um penetrômetro manual para diagnosticar a profundidade de impedimento radicular; medidas avaliadoras das plantas foram área foliar, comprimento de caule, número de folhas e produtividade por hectare. Os preparos conservacionistas reduziram as perdas de solo e água e proporcionaram uma menor amplitude na temperatura diária, maior umidade do solo, mas a produtividade no PDsC ficou aquém dos preparos convencionais. Esse resultado no PDsC foi diretamente influenciado pelo menor aprofundamento das raízes, sendo esse conseqüência de vários fatores como presença de camada de impedimento, não possuir camalhão, posicionamento mais superficial da adubação de base e condições iniciais favoráveis de temperatura e umidade do solo. Contudo, houve grande interação de fatores, tornando complexa a explicação do resultado obtido, pois fatores como a adubação superficial favoreceu as perdas de P e K solúvel, diminuindo a disponibilidade; a camada de impedimento diminuiu o volume de solo explorado pelas raízes e a capacidade de armazenamento de água, sendo que os manejos PDcCC e PDsC ficaram em torno de 15 dias fora da faixa de disponibilidade de água, na camada de 0 a 0,06 m.
72

Všeobecný význam porostů rychle rostoucích topolů. / Universal meaning of growths the fast - growing poplars.

CHALOUPKA, Jiří January 2009 (has links)
The aim of those thesis was an analysis of a off - producing function the fast - growing growths namely in the several standpoints. I deal with a prosecution of the fast - growing poplars in a theoretic part at first. Then I specifyed the three main functions the fast - growing timber species namely at an off - producing usage. It means a function ameliorative, sanitation, aesthetic, biological, produce and insulative here. Mostly I then attended to an water and windy erosion.
73

Zjišťování poklesu půdního horizontu na odvodněných plochách geodetickými metodami. / Geodetical detection of soil horizont subsidence in tile drainet areas.

PICHLÍKOVÁ, Jana January 2009 (has links)
The goal of my work is to verify the effectiveness of various methods of collecting geodetic data in order to locate the decline of soil horizont in the dewatered areas.
74

Návrh protierozní a protipovodňové ochrany v zájmovém území reagující na klimatickou změnu / Design of erosion and flood control measures in the study case area responding to climate change

Mrázek, Vojtěch January 2022 (has links)
The aim of the work is to design anti-erosion and flood protection in the area of interest KÚ Lukavec to the current state and responding to climate change. At the same time, it is necessary to assess the degree of erosion threat to the soil and analyze runoff conditions in critical areas. The introductory part summarizes information about the studied area and methods for calculation. The erosion analysis is processed in the design part and suitable anti-erosion and anti-flood measures will be proposed. DesQ-MaxQ software was used to calculate the runoff conditions, graphical outputs and analysis of erosion conditions were created in the ArcGIS environment.
75

Zpracování plánu společných zařízení pro komplexní pozemkovou úpravu

ANDREJKOVÁ, Michaela January 2019 (has links)
This diploma thesis is focused on the elaboration of a plan of joint facilities for comprehensive land treatment in the selected cadastral territory of Dolní Třebonín, located in the South Bohemian Region. The purpose of the thesis is the characterization and evaluation of the cadastral area as part of the need to implement these joint facilities: anti-erosion measures for the protection of agricultural land resources, measures for access to land, measures for protection and creation of the environment and water management measures. The theoretical part of this work is literary research. This section explains basic concepts such as land treatment, forms of land treatment, exploration works and joint facilities. The practical part describes the characteristics of the selected area, the exploration work in the given area and the proposal of the common facilities. The results are processed in textual and graphical form using ArcMap 10.0.
76

Regionalização hidrológica de vazões e de cargas difusas de sólidos suspensos totais para o programa ProdutorES de Água e o pagamento de serviços ambientais. Estudo de caso: bacia hidrográfica do rio Benevente, ES / Hydrological regionalization of flows and loads of total suspend solids for the program Producers of Water and the payment of environmental services. Case study of river basin Benevente, ES

Henrique, Cesar Sperchi 19 November 2009 (has links)
O sistema de pagamento por serviços ambientais de uma bacia hidrográfica pode ser economicamente atrativo e ecologicamente importante. Programas como o Produtor de Água compensam economicamente proprietários a montante da bacia que utilizam de manejo adequado do uso do solo, e do reflorestamento, para evitar a erosão hídrica, o aumento de cargas poluidoras difusas, e aumentar a disponibilidade e qualidade de água. Por conseqüência usuários de água, a jusante da bacia, são beneficiados, por exemplo, as estações de tratamento de água. Este trabalho tem como objetivo, a partir de metodologias de pagamentos de serviços ambientais, regionalizar hidrologicamente a quantidade e qualidade de água do rio Benevente para dar subsídios ao programa de produtores de água de sua bacia hidrográfica. O trabalho foi desenvolvido na parte média e alta da bacia hidrográfica do Benevente, localizada ao sul do Estado do Espírito Santo, com área de drenagem de aproximadamente 1260 \'KM POT.2\'. Á área de drenagem do local do estudo é de 825,24 \'KM POT.2\'. Parte da metodologia consistiu no levantamento de dados quantitativos e qualitativos de água ao longo do rio Benevente, nos últimos anos. De posse dos dados de vazão, concentração de SST e da área de drenagem, foram calculadas as cargas específicas difusas de SST, em termos de Kg/ha.ano e as cargas totais difusas em termos de ton/ano. A carga específica média de SST para a bacia foi de 194 Kg/ha.ano, a carga total média de SST foi de 11.238 ton/ano. A metodologia de regionalização hidrológica de cargas de SST por meio de curvas de permanência mostrou que há uma ampla variação de cargas produzidas na bacia sobre diferentes condições hidrológicas. Por exemplo, para uma faixa de permanências de 40% a 60% a variação de produção específica regional de SST foi de 58,54 a 825,14 Kg/ha.ano. A utilização da metodologia das curvas de permanência quali-quantitativas para a proposição de cenários ambientais em vista das mudanças de uso e ocupação do solo, propostos pelos programas de PSA, permitiu estimar o Percentual de Abatimento de Sedimentação (P.A.S) e consequentemente o Percentual de Abatimento de Erosão (P.A.E), na bacia. Encontrou-se um P.A.E de 36,9% entre o cenário atual e o cenário com amento de 20% da área florestal da bacia. Com este resultado estimou-se um total arrecadado na bacia pelo P.S.A de 825.195 R$/ano. Com as metodologias propostas também foi calculada a perda de solo atual da bacia, em relação à estação de amostragem mais a jusante. A taxa estimada foi de 200.123 ton/ano. / Systems of payment for environmental services of a catchment area can be economically attractive and ecologically important. Programs such as Producers of Water economically compensate owners upstream of the basin using the proper management of land use, and reforestation to prevent erosion, increased pollution loads diffuse and increase the availability and quality of water. Consequently water users downstream of the basin, are benefited, for example, sewage water treatment. This paper aims, methodologies from payments for environmental services, regionalization of hydrologically the quantity and quality of water from the river Benevente to aid the program producer of water from its watershed. The study was conducted in the middle and upper catchment of the Benevente, located south of Espírito Santo, with drainage area of approximately 1260 \'KM POT.2\'. The drainage area of the study is 825.24 \'KM POT.2\'. Part of the survey methodology consisted of qualitative and quantitative data of water along the river Benevente in recent years. With these data we calculated the diffuse specific loads of TSS, in terms of Kg/ha.year. The specific load average TSS for the basin was 194 Kg/ha.year, the total load average SST was 11,238 Ton/year. The methodology of regionalization of hydrological loads of TSS through curves of duration showed that there remain a wide range of loads in the basin produced on different hydrological conditions. For example, for a range of stays of 40% to 60% of the variation of specific regional production of TSS was 58.54 to 825.14 Kg/ha.year . Using the methodology of the curves remain qualitative and quantitative for the proposition environmental scenarios in view of land use change and land use, proposed by the PSA program, estimated the rate of reduction on Sedimentation (PAS) and consequently the rate Abatement of Erosion (PAE) in the basin. Found a PAE of 36.9% from the current scenario and the scenario with budget of 20% of the forest area of the basin. With this estimated result a total collected in the basin by the PSA for R$ 825,195/year. With the proposed methodology was also calculated the soil loss on the basin in relation to the sampling station further downstream. The rate was estimated at 200,123 ton/year.
77

Reservorios y flujos de carbono en un gradiente de intensificación de usos del suelo de un ecosistema mediterráneo: factores de control y capacidad de secuestro de carbono

Almagro Bonmatí, María 14 October 2011 (has links)
Se estudia el ciclo del carbono en diferentes usos del suelo (uso forestal, campo agrícola abandonado y olivar de secano) de un ecosistema mediterráneo ante la perspectiva del cambio climático. La hipótesis general de esta tesis es que los cambios en los patrones (estructura y distribución espacial) y tipo de vegetación resultantes de la intensificación de los usos del suelo causarán alteraciones en las condiciones microclimáticas (temperatura y humedad del suelo) y en las características del micrositio (comunidades microbianas del suelo, calidad de los detritos procedentes de la vegetación, patrones de escorrentía y erosión del suelo), que afectarán a los flujos de carbono (entradas y salidas), a los factores que controlan dichos flujos y a la capacidad de secuestro de carbono del ecosistema. Para validar dicha hipótesis se plantean los siguientes objetivos generales: i) caracterizar los reservorios y los flujos de carbono; ii) evaluar la importancia relativa de los diferentes componentes del balance de carbono; e iii) identificar los factores que controlan los flujos de carbono más importantes que regulan la capacidad subterránea de secuestro del mismo en un gradiente de intensificación de usos del suelo. / This thesis provides a useful database of carbon (C) pools and fluxes under different land uses (open forest, old-field, olive grove) in a dry Mediterranean ecosystem of Southeast Spain. To understand how global climate change and alterations in land use are affecting Mediterranean soil biogeochemical processes, I completed four studies that investigated the different C components within the C balance of each land use type, the interactions between them, and their controlling factors. The main objectives were: 1) to quantify C pools and fluxes (outputs and inputs) under different land uses over a three-year period (2006-2009); 2) to compare two C balance approaches based on steady-state or non-steady-state conditions in order to assess the relative importance of the different C fluxes within the C balance of each land use type; and 3) to identify the factors controlling the main C fluxes within each land use type.
78

Regionalização hidrológica de vazões e de cargas difusas de sólidos suspensos totais para o programa ProdutorES de Água e o pagamento de serviços ambientais. Estudo de caso: bacia hidrográfica do rio Benevente, ES / Hydrological regionalization of flows and loads of total suspend solids for the program Producers of Water and the payment of environmental services. Case study of river basin Benevente, ES

Cesar Sperchi Henrique 19 November 2009 (has links)
O sistema de pagamento por serviços ambientais de uma bacia hidrográfica pode ser economicamente atrativo e ecologicamente importante. Programas como o Produtor de Água compensam economicamente proprietários a montante da bacia que utilizam de manejo adequado do uso do solo, e do reflorestamento, para evitar a erosão hídrica, o aumento de cargas poluidoras difusas, e aumentar a disponibilidade e qualidade de água. Por conseqüência usuários de água, a jusante da bacia, são beneficiados, por exemplo, as estações de tratamento de água. Este trabalho tem como objetivo, a partir de metodologias de pagamentos de serviços ambientais, regionalizar hidrologicamente a quantidade e qualidade de água do rio Benevente para dar subsídios ao programa de produtores de água de sua bacia hidrográfica. O trabalho foi desenvolvido na parte média e alta da bacia hidrográfica do Benevente, localizada ao sul do Estado do Espírito Santo, com área de drenagem de aproximadamente 1260 \'KM POT.2\'. Á área de drenagem do local do estudo é de 825,24 \'KM POT.2\'. Parte da metodologia consistiu no levantamento de dados quantitativos e qualitativos de água ao longo do rio Benevente, nos últimos anos. De posse dos dados de vazão, concentração de SST e da área de drenagem, foram calculadas as cargas específicas difusas de SST, em termos de Kg/ha.ano e as cargas totais difusas em termos de ton/ano. A carga específica média de SST para a bacia foi de 194 Kg/ha.ano, a carga total média de SST foi de 11.238 ton/ano. A metodologia de regionalização hidrológica de cargas de SST por meio de curvas de permanência mostrou que há uma ampla variação de cargas produzidas na bacia sobre diferentes condições hidrológicas. Por exemplo, para uma faixa de permanências de 40% a 60% a variação de produção específica regional de SST foi de 58,54 a 825,14 Kg/ha.ano. A utilização da metodologia das curvas de permanência quali-quantitativas para a proposição de cenários ambientais em vista das mudanças de uso e ocupação do solo, propostos pelos programas de PSA, permitiu estimar o Percentual de Abatimento de Sedimentação (P.A.S) e consequentemente o Percentual de Abatimento de Erosão (P.A.E), na bacia. Encontrou-se um P.A.E de 36,9% entre o cenário atual e o cenário com amento de 20% da área florestal da bacia. Com este resultado estimou-se um total arrecadado na bacia pelo P.S.A de 825.195 R$/ano. Com as metodologias propostas também foi calculada a perda de solo atual da bacia, em relação à estação de amostragem mais a jusante. A taxa estimada foi de 200.123 ton/ano. / Systems of payment for environmental services of a catchment area can be economically attractive and ecologically important. Programs such as Producers of Water economically compensate owners upstream of the basin using the proper management of land use, and reforestation to prevent erosion, increased pollution loads diffuse and increase the availability and quality of water. Consequently water users downstream of the basin, are benefited, for example, sewage water treatment. This paper aims, methodologies from payments for environmental services, regionalization of hydrologically the quantity and quality of water from the river Benevente to aid the program producer of water from its watershed. The study was conducted in the middle and upper catchment of the Benevente, located south of Espírito Santo, with drainage area of approximately 1260 \'KM POT.2\'. The drainage area of the study is 825.24 \'KM POT.2\'. Part of the survey methodology consisted of qualitative and quantitative data of water along the river Benevente in recent years. With these data we calculated the diffuse specific loads of TSS, in terms of Kg/ha.year. The specific load average TSS for the basin was 194 Kg/ha.year, the total load average SST was 11,238 Ton/year. The methodology of regionalization of hydrological loads of TSS through curves of duration showed that there remain a wide range of loads in the basin produced on different hydrological conditions. For example, for a range of stays of 40% to 60% of the variation of specific regional production of TSS was 58.54 to 825.14 Kg/ha.year . Using the methodology of the curves remain qualitative and quantitative for the proposition environmental scenarios in view of land use change and land use, proposed by the PSA program, estimated the rate of reduction on Sedimentation (PAS) and consequently the rate Abatement of Erosion (PAE) in the basin. Found a PAE of 36.9% from the current scenario and the scenario with budget of 20% of the forest area of the basin. With this estimated result a total collected in the basin by the PSA for R$ 825,195/year. With the proposed methodology was also calculated the soil loss on the basin in relation to the sampling station further downstream. The rate was estimated at 200,123 ton/year.
79

Nonpoint Source Pollutant Modeling in Small Agricultural Watersheds with the Water Erosion Prediction Project

Ryan McGehee (14054223) 04 November 2022 (has links)
<p>Current watershed-scale, nonpoint source (NPS) pollution models do not represent the processes and impacts of agricultural best management practices (BMP) on water quality with sufficient detail. To begin addressing this gap, a novel process-based, watershed-scale, water quality model (WEPP-WQ) was developed based on the Water Erosion Prediction Project (WEPP) and the Soil and Water Assessment Tool (SWAT) models. The proposed model was validated at both hillslope and watershed scales for runoff, sediment, and both soluble and particulate forms of nitrogen and phosphorus. WEPP-WQ is now one of only two models which simulates BMP impacts on water quality in ‘high’ detail, and it is the only one not based on USLE sediment predictions. Model validations indicated that particulate nutrient predictions were better than soluble nutrient predictions for both nitrogen and phosphorus. Predictions of uniform conditions outperformed nonuniform conditions, and calibrated model simulations performed better than uncalibrated model simulations. Applications of these kinds of models in real-world, historical simulations are often limited by a lack of field-scale agricultural management inputs. Therefore, a prototype tool was developed to derive management inputs for hydrologic models from remotely sensed imagery at field-scale resolution. At present, only predictions of crop, cover crop, and tillage practice inference are supported and were validated at annual and average annual time intervals based on data availability for the various management endpoints. Extraction model training and validation were substantially limited by relatively small field areas in the observed management dataset. Both of these efforts contribute to computational modeling research and applications pertaining to agricultural systems and their impacts on the environment.</p>

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