4 results

Sensitivity analysis and calibration of SWAT model applied to a watershead in southeastern Brazil

Thatiana Aparecida Lelis, Maria Lúcia Calijuri, Aníbal da Fonseca Santiago, Dario Cardoso de Lima, Everton de Oliveira Rocha

01/Apr/2012

Estimates of water and soil losses have been carried out worldwide, using empirical or conceptual models, such as SWAT (Soil and Water Assessment Tool). SWAT, widely used to predict the impact of changes in soil use and management on soil loss and stream flow rate, is extremely sensitive to the quality of input data. Consequently, prior to an application of the model, a sensitivity analysis is required to deal more carefully and with more precision with certain data, reducing the […]

Sediment retention in an agriculture field by riparian forest in Goiatuba, Goiás state (Brazil)

Diléia Santana dos Santos, Gerd Sparovek

01/Oct/2011

Riparian forests are generally associated to sediment retention and consequently to the mitigation of off-site erosion, but few studies have investigated this effect. The purpose of this study was to analyze the efficiency of riparian forests on the retention of sediment from crop lands using the 137Cs technique. Sampling in an area located in Central Brazil, under intensive cotton farming in a conventional system, was performed in July 2005, using cross-sectional analyses. The 137Cs technique proved adequate for estimating the […]

Alternative scenario simulation of land use in a watershed through geoprocessing and modeling techniques

R. E. Machado, C. A. Vetorazzi, A. C. Xavier

01/Aug/2003

The model SWAT (Soil and Water Assessment Tool) was used to simulate alternative scenarios of land use in Ribeirão dos Marins watershed, in Piracicaba, State of São Paulo, Brazil, for the biennial period 1999/2000. Two scenarios were simulated. The first one (scenario 1) was based on the current land use except for the introduction of a continuous riparian buffer of 30 m along the drainage network and of 50 m around the springs, in accordance to Brazil’s environmental legislation. In […]

Effectiveness of stone barrier contours on sediment retention and improvement of chemical and physical properties in a litholic soil

J.R.C. Silva, F. J. da Silva

01/Sep/1997

Litholic soils are characterized by moderate to high erodibility and low depth. Due to these attributes, litholic soils require effective conservation practices protecting their thin top soil layer from the high erosion rates in the semiarid regions of the State of Ceará, Brazil. While the consequences of erosion on these soils are well known, the long term effects of this conservation practice on the rate of soil losses and improvement of their properties have been scarcely studied. Mass of retained […]