Assessment of National Soil Loss and Potential Erosion Area using the Digital Detailed Soil Maps

This study was performed to estimate the soil loss on a national scale and grade regions with the potential risk of soil erosion. Universal soil loss equation (USLE) for rainfall and runoff erosivity factors (R), cover management factors (C) and support practice factors (P) and revised USLE for soil erodibility factors (K) and topographic factors (LS) were used. To estimate the soil loss, the whole nation was divided into 21,337 groups according to city county, soil phase and land use type. The R factors were high in the southern coast of Gyeongnam and Jeonnam and part of the western coast of Gyeonggi and low in the inland and eastern coast of Gyeongbuk. The K factors were higher in the regions located on the lower streams of rivers and the plain lands of the western coast of Chungnam and Jeonbuk. The average slope of upland areas in Pyeongchang-gun was the steepest of 30.1%. The foot-slope areas from the Taebaek Mountains to the Sobaek Mountains had steep uplands. Total soil loss of Korea was estimated as in 2004. The potential risk of soil erosion in upland was the severest in Gyeongnam and the amount of soil erosion was the greatest in Jeonnam. The regions in which annual soil loss was estimated over were graded as "the very severe" and their acreage was in 2004. The soil erosion maps of city/county of Korea were made based on digital soil maps with 1:25,000 scale.