A GIS-Based Procedure for Automatically Calculating Soil Loss from the UniversalSoil Loss Equation: GISus-M
Abstract. The integration of methods for calculating soil loss caused by water erosion using a geoprocessing system is important to enable investigations of soil erosion over large areas. Geographic information system (GIS)-based procedures have been used in soil erosion studies; however in most cases it is difficult to integrate the functionality in a single system to compute all soil loss factors. We developed a system able to combine all factors of the Universal Soil Loss Equation (USLE) with the computer functionality of a GIS. The GISus-M provides tools to compute the topographic (LS-factor) and cover and management (C-factor) from methods using remote sensing data. The other factors necessary to use the USLE, including soil erodibility, rainfall erosivity, and conservation practices, are also integrated in this tool. We describe in detail the GISus-M system and show its application in the RibeirA£o do Salto sub-basin. From our new system, it is possible to work with different types of databases, making the GIS-procedure developed here a useful tool for researchers and decision makers to use spatial data and different methods to create future scenarios of soil erosion risk.