Spatial soil loss estimation using an integrated GIS-based revised universal soil loss equation (RUSLE) in selected watersheds in northern Ghana

Abstract

This study used thespatially integrated RUSLE to estimate annual soil loss and spatial distribution of soil loss severity classes for nine (9) reservoir  catchments in northern Ghana.This model is an empirical model with five (5)main input parameters: rainfall erosivity, soil erodibility, slope  length/steepness, landcover management and erosion management practice factors. Estimated annual soil loss rate ranged from 0 – 96.30 t/ha/y. Estimated mean annual soil loss ranged from 3.71 – 8.17 %. The severity of annual soil loss rates ranged from very low class (0.0 – 1.0 t/ha/y) to very high class (> 60.0 t/ha/y). Across the nine (9) catchments, the very low soil loss severity class was noted to constitute a larger portion of between 36.70 to 67.50 %. The moderate soil severity class was noted as the highest contributor to total annual soil loss. Soil and water conservation measures are required in the watershed to reduce soil loss.

Keywords: Watershed, soil loss, Integrated GIS-based RUSLE model, surface water resources, lixisols