The Use of Geographic Information System Soil Erosion Assessment in the North-east of Libya

Abstract

The aim of this paper is to predict annual soil losses in the North-east of Libya. The universal soil loss equation (USLE) and geographic information system (GIS) have been used to map and quantify annual soil loss in the study area. GIS were used to map USLE parameters which are: Rainfall erosivity (R), Soil Erodibility (K), Slope length factor (L), Slope steepness factor (S), Crop and management factor (C) and Conservation factor (P). Individual GIS files were built for each factor of the USLE and combined by utilising the grid‐cell modelling function in GIS to predict soil loss in the spatial domain. The data which was used included: climate data, soil survey data and topographic maps. The results have shown that the study area is at erosion risk. Four main classes were found: low, moderate, high and intensive erosion. Most of the intensive erosion risk were on the best quality soils in the area. Therefore, soil conservation plans are needed to reduce erosion risks and improve crop yield. The outputs show that GIS and USLE can be applied to determine field‐scale soil loss both quantitatively and spatially, and predict erosion hazard over large watersheds in Libya.The results prove that GIS permit more effective and accurate application of the USLE model for small watersheds provided that sufficient spatial data are available.

Key Words: North-eastern Libya, GIS, soil erosion, USLE.