Forming Of Erosion Risk Map of Buyukcay Basin (Elazig)

Abstract

In this study, it has been aimed to carry out erosion risk analysis of Buyukcay Basin using weighted overlay method. Located in the southeast of Elazig, Buyukcay Basin is surrounded by Mastar Mountain and Keban Dam. The basin's having been cut by a fault in NE-SW direction have caused significant difference in elevation. Vegetation is sparse in the basin, where slope values are high. Very severe erosions have been seen in Buyukcay Basin due to its climate, geomorphologic and vegetation features. As a result of the erosion, material especially carried from mountain areas in north and north-west, affects the agriculture lands in the east and west of the basin. Besides, carried material causes siltation in the Keban Dam Lake. In this study, erosion risk analysis has been done for the basin by using slope, vegetation, drainage density and soil brightness (texture). Risk analysis has been done using Geographic Information Systems and Remote Sensing methods. Significance of factors on field observations and erosion have been assigned and weight value has been added to these factors. Collecting factor maps whose weigts have been determined, risk map has been created. According to the erosion risk analysis, an area of 24\% in Buyukcay Basin is high-risk areas to the erosion. Medium-risk areas and low-risk areas have the rates of 44 \% and 25\%, respectively. Based on these results, the erosion risk in Buyukcay Basin is high. For this reason, erosion control studies must be accelerated within the scope of microbasin activities.