Estimating spatial distribution of soil loss over Seyhan River Basin in Turkey

The purpose of this study was to investigate the spatial distribution of annual soil loss in Seyhan River Basin using USLE model. A geographic information system (GIS) was used to generate maps of the USLE factors which are rainfall erosivity (R), soil erodibility (K), slope length and steepness (LS), cover (C) and conservation practices (P) factors. By integrating these maps in GIS, spatial distribution of soil loss over the Seyhan River Basin was obtained. Annual average soil loss for the Seyhan River Basin was 16.38 t ha-1 y-1. Annual soil loss more than 200 t ha-1 y-1 in pixel level was in the southern region, while the northern region showed the lower annual values. These results are verified by comparing sediment yield measurements in the basin. An area about 198.25 km2 (0.96%) experiences extremely severe erosion risk, which needs suitable conservation measures to be adopted on a priority basis. The spatial distribution of erosion risk classes estimated 61.03% very low, 8.76% low, 23.52% moderate, 4.03% severe and 1.70% very severe. Thus, the USLE model was used in a GIS environment to identify regions susceptible to water erosion and needing immediate soil conservation planning and application in the Seyhan River Basin in Turkey. © 2006 Elsevier B.V. All rights reserved