Kuruçay Stream basin, located in the Edremit district in northwest Turkey, is a small, narrow and long basin with an area of 17.3 km², extending in the N–S direction, located on the southern slopes of Mount Ida. The study was carried out to determine the soil erosion susceptibility and distribution of Kuruçay Stream basin, as well as to estimate the annual average amount of soil loss through the Revised Universal Soil Loss Equation (RUSLE) model using Geographical Information Systems (GIS). To apply the equation to the basin, data layers for rainfall erosivity (R), soil erodibility (K), slope length (L) and slope steepness (S), landcover management (C), and support practice (P) factors were generated. The layers were then overlaid, calculations were made and erosion susceptibility classes were generated. Thus, the spatial distribution of erosion susceptibility classes and the annual estimated amount of soil loss were determined. Based on the results, the Kuruçay Stream basin was found to have five distinct erosion susceptibility levels: low, moderate, high, severe, and extremely severe. Accordingly, 76% of the basin has low, 11.3% moderate, 6% high, 2.9% severe and finally 3.7% very severe erosion susceptibility. The Kuruçay Stream basin shows similar characteristics with the neighbouring river basins in terms of erosion sensitivity.

Basin, geographical information systems, RUSLE, soil erosion