Erosion analysis of Şahin creek watershed (NW of Turkey) using GIS based on Rusle (3d) method

Abstract

The aim of this study is to determine the potential erosion risk and to predict long time average annual soil loss resulting from raindrop splash and runoff and controlling factors in Şahin Creek watershed which is located on the northern part of Edremit Gulf in the Northwest of Turkey. For this purpose in order to determine controlling factors and find out the rate of potential erosion risk, Geographical Information Systems (GIS) based Revised Universal Soil Loss Equation (RUSLE) model was used. All factors used in the RUSLE were calculated for the watershed using local data. RUSLE-factor maps were made. According to result of this study five erosion risk classes which are low, slight, moderate, high, severe were defined. The mean values of the R-factor, K-factor, LS-factor, C-factor and P-factor were 305 km -2 h -1 a -1 (MJ ha -1 year -1 ), 0.54 Mg h MJ -1 mm -1 (ton ha -1 year -1 ), 15.03, 0.05 and 0.95, respectively. The mean annual soil loss is estimated to be 43 tons per year per hectare. There is more erosion in the upland on the north and step slopes in the west of Şahin creek watershed.