A Comparative Analysis of Annual Surface Soil Erosion before and after the River Improvement Project in the Geumgang Basin Using the RUSLE

In this study, the annual surface soil erosion amount of before (2007 year) and after (2015 year) the river improvement projects were calculated using RUSLE (Revised Universal Soil Loss Equation) in the Geumgang basin (Daecheong-Dam to Geumgang Estuary-Bank). After the results were classified into five classes, the results were compared and analyzed with the results of the change in the land cover. In order to generate each factor of RUSLE, various spatial information data, such as land cover maps for 2007 and 2015 years, national basic spatial information, soil map, and average annual precipitation data were utilized. The results of the analysis are as follows: 1) annual surface soil erosion in the study area increased the area of class 1 in 2015 years compared to 2007, 2) the area of class 2, 3 and 5 decreased, 3) the area of class 4 increased. It is believed that the average annual amount of surface soil erosion decreased in most areas due to the reduction of annual average precipitation, the formation of ecological parks, the expansion of artificial facilities, and the reduction of illegal farmland.