Effect of different spatial resolutions of digital elevation models on soil loss estimation

Abstract

The Universal Revised Soil Loss Equation (RUSLE) is one of the most widely used models for estimating soil erosion risk. Among the input layers that have the greatest impact on soil loss modeling is the combined length and slope angle (LS factor) that describes the effect of topography on soil erosion. In this study, we calculated the LS factor based on Digital Elevation Models (DEM) of different spatial resolutions for a tropical basin. The LS factor calculation was per-formed using the LS-TOOL tool, which incorporates a multiple flow algorithm and contributes to an accurate estimation of flow accumulation. The LS factor dataset was calculated using 5 to 90 m spatial resolution MDEs across the Guariroba Basin, resulting in different delineation of areas at risk of soil erosion compared to low-resolution datasets. This combined approach of using Geographic Information System software tools with different resolution MDEs shows that the applica-bility of freely provided medium resolution MDEs does not compromise the estimation of average soil loss.