Erosion Risk Analysis in Unlendi Dam Basin

Abstract

In this study, erosion areas, rates and degrees of erosion were determined by Revised Universal Soil Loss Equation (RUSLE 3D) method and Remote Sensing (RS) on the Geographical Information System (GIS) of the Ünlendi dam constructed on the Acıçay stream, Tuzluca-Iğdır. The precipitation data of 14 meteorology stations for rainfall erosion factor (R); large soil groups and characteristics in the basin for soil erosion susceptibility factor (K); the equation for slope length and slope steepness factor (LS); Sentinel-2 satellite image and the equation for vegetation cover factor (C); classification of slopes for erosion control factor (P) were used. Digital Elevation Model in 5x5 meters resolution, factors and erosion maps were created by using GIS. The average soil loss was found to be moderate (24.1 t.ha -1 .y -1 ) and above the average of Türkiye (8.24 t.ha -1 .y -1 ). In the erosion map, susceptibilities were determined as light in 37.3% (1932 ha); moderate in 14.9% (772 ha); strong in 14.7% (758 ha); severe in 28.4% (1468 ha) and very severe in 4.7% (244 ha). Insufficient vegetation and its destruction, steep slopes, overgrazing in pasture increase the erosion susceptibility. In risky areas, due to the nature of the region, terracing and afforestation studies have been proposed, considering the steepness of the slope.