EROSION ANALYSIS OF FINDIKLI CREEK CATCHMENT (NW OF TURKEY) USING GIS BASED ON RUSLE (3D) METHOD

摘要

Soil erosion by water is one of the major causes of land degradation in Turkey. But the problem has not yet been treated in detail, although it affects vast areas. 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 as well as controlling factors in Findikli 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 on Revised Universal Soil Loss Equation (RUSLE) model were used. All factors in the RUSLE were calculated for the watershed using local data, and RUSLE-factor maps were made. According to the result of this study, five erosion risk classes are defined as low, slight, moderate, high, and severe ones. 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/year), 0.55 Mg h MJ~(-1) mm~(-1) (tons/ha/year), 15.50, 0.07 and 0.90, respectively. The mean value of the annual average soil loss was assigned to be 66.5 tons/ha/year. There is more erosion in the upland on the north and step slopes in the west of Findikli creek watershed.