Determination of soil loss by laminar erosion in the hydrographic basin of stream Marrecas, RS, Brazil

Abstract

The reservoir silting is directly related to soil erosion and the greater the amount of sediment contributed to its interior, lower storage capacity and therefore lifetime. Since it is very expensive to monitor erosion throughout the watershed, it is common the use of mathematical modeling. The Universal Soil Loss Equation (USLE) was developed in order to predict soil loss averages over long periods and conditions. The aim of this study was to apply the USLE in the Marrecas’ basin to estimate the generation of sediment through laminar erosion. The USLE calculation was accomplished through the use of GIS (Geographic Information System). The results indicate that the study watershed has a low generation of sediment by laminar erosion, with most of its length inserted into classes with very low to low soil loss. The use of Geographic Information Systems (GIS), coupled with Remote Sensing and Digital Cartography, allow obtaining the factors that make up the USLE, enabling the generation of spatial analysis of sediments in the basin, supporting the selection of conservation practices.