Coupling Universal Soil Loss Equation and GIS Techniques for Estimation of Soil Loss and Sediment Yield in Algash Basin

Abstract

Soil erosion is a global problem which has social, environmental and economical adverse effects. Soil erosion reduces soil productivity and water quality, therefore this study was conducted as an effort to estimate the average and total soil loss and moreover the total sediment yield in Algash water basin which extends from Eritrea to the downstream in east of Sudan. The study utilized from GIS and remote sensing to analyze the soil loss, based on Universal Soil Loss Equation (USLE), this model is one of the most widespread models are used for soil loss estimation. Soil erosion was determined as function of five parameters using USLE, the rainfall erosivity factor (R) was estimated from annual mean rainfall for last 8 years, the soil erodiblity factor (K) was determined based on soil characteristics, topographic factor (LS) was estimated using SRTM, the forth factor is crop management factor (C) and it was estimated using Normalized Difference Vegetation Index (NDVI) and the support practice factor (P) was estimated using derived slope data and a produced land cover map. Based on the above analysis the annual average soil loss ranged from zero to 118.86 ton/ha.year per pixel and the total soil loss from the whole study area was found to be 32,916,840.87 ton/ha.year.