917 resultados para radial hydraulic conductivity


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The purpose of this experiment was to evaluate the hydro-physical attributes of the Red Oxisol cultivated with maize in Jaboticabal, São Paulo State, Brazil, under different systems of use and periods of adoption of managements. The experiment was arranged in a completely randomized design with split-plot arrangement, with six replications and the treatments were: six years of no-tillage system (SPD6), eight years of no-tillage system (SPD8), ten years of no-tillage system (SPD10), conventional tillage system (SPC) and an adjacent area of native forest (NF). The soil penetration resistance (PR), density, macroporosity, microporosity of the soil in layers of 0-0.05; 0.05-0.10 and 0.10-0.20 m, and the saturated hydraulic conductivity (Kθ) in 0.15 m depth were evaluated. It was found that the PR conditions were favorable for the cultivation to 0.20 m, indicating a structure preserved even after soil chiseling. Furthermore, the Kθ in the soil showed similar behavior between SPC and periods of SPD, although this was shown in a part of maize cycle, macroporosity values near 0.10 m3 m-3 and soil water tensions near 0.09 MPa.

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The Guarani aquifer system (GAS) represents one of the biggest aquifers in the world and is the most relevant groundwater resource in South America. For the first time, by combining field and laboratory measurements, a high-resolution aquifer analog model of fluvial-aeolian sediments of the GAS in São Paulo State (Brazil) is constructed. Three parallel sections of frontal outcrops, 28 m × 5.8 m, and two parallel sections of lateral outcrops, 7 m × 5.8 m, are recorded during open-pit mining of sandy sediments and describe in detail the three-dimensional distribution of the local lithofacies and hydrofacies. Variations of hydraulic conductivity, K, and porosity, n, are resolved on the centimeter scale, and the most permeable units of the fluvial-aeolian facies association are identified. The constructed aquifer analog model shows moderate hydraulic heterogeneity and a mean K value of 1.36 × 10-4 m/s, which is greater than the reported range of K values for the entire GAS in São Paulo State. The results suggest that the examined sedimentary unit constitutes a relevant portion of the GAS in São Paulo State in the context of groundwater extraction and pollution. Moreover, the constructed aquifer analog is considered an ideal basis for future numerical model experiments, aiming at in-depth understanding of the groundwater flow and contaminant transport patterns at this GAS portion or at comparable fluvial-aeolian facies associations. © 2013 Springer-Verlag Berlin Heidelberg.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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Pós-graduação em Geociências e Meio Ambiente - IGCE

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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Pós-graduação em Geociências e Meio Ambiente - IGCE

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)