PREDICTING SOIL EROSION AND SEDIMENT YIELD IN THE TAPACURÁ CATCHMENT, BRAZIL

Abstract

The EPM is a model for qualifying the erosion severity and estimating the total annual sediment yield. The EPM uses empirical coefficients (erodibility coefficient, protection coefficient and erosion coefficient) and a matrix of the basin physical characteristics. The EPM gives a quantitative estimation of erosion intensity as well as the estimation of sediment yield and transportation. To analyze the suitability of the Gavrilovic method for use with GIS techniques, we prepared cartographic data on geology, pedology, slope, temperature and land use in digital form. A raster-based Geographic Information System (GIS) was applied to generate the erosion-severity and sediment yield maps. In order to validate the EPM estimated erosion, data annual sediment yield were collected between 1999 and 2007. The results showed a mean sediment delivery ratio (SDR) of around 8% and a calculated mean sediment yield of 0.108 t/ha/year, which is close to the observed one, 0.169 t/ha/year. The obtained soil loss map could be considered as a useful tool for environmental monitoring and water resources management.