The Estimation of the Potential Soil Erosion Quantity of Forest Watersheds in Gyeongsangbuk-do Using USLE

Abstract

In this study, we derived the calculating formula for the standard sediment delivery rate (SDR) of forest watersheds by comparing and analyzing the potential quantity soil erosion using the universal soil loss equation (USLE) and the actual measurement based on the dredging data of check dams. In addition, by extracting forest watersheds in Gyeongsangbuk-do using GIS and applying them to it, we investigated the usability as basic data for the establishment of a fundamental construction plan for check dams in Gyeongsangbuk-do. As a result, the sediment delivery rate was high in small watersheds about 0.1㎢ compared to the predicted amount, but rapidly decreased in large watersheds of 1㎢ or more. Based on this, we figured out that the calculation formula for the standard sediment delivery rate of forest watersheds is SDR=0.2021×Area-0.712. Furthermore, after calculating the potential soil erosion quantity of forest watersheds in Gyeongsangbuk-do using USLE, it was estimated that a total of 9,897,192ton/year of sediment yields can be produced annually. Therefore, additional 2,743 check dams per year are required in order to control potential soil erosion of the forest watersheds in Gyeongsangbuk-do.