Modeling the Impacts of Land Use Changes on Soil Erosion at the River Basin Scale

The potential for soil erosion is strongly affected by land use. A proper modeling approach should be selected to explicitly assess the impacts of land use changes on soil erosion at a river basin scale. The reliability of simulation results from erosion models is circumscribed by considerable spatial variation in many parameters. In this study, a grid based distributed soil erosion and sediment transport model was used in conjunction with a laboratory rainfall simulation experiment to determine the impact of land use changes on soil erosion and sediment yield in a river basin during individual storms. Land use changes in the Lushi Basin, primarily in Henan, China, were analyzed by comparing the historical land use maps in 1990 and 1995. Through comparing the results for four selected storms that were compiled using these two land use maps, it was found that the average erosion rates increased from 1989 to 1996. The increase in average erosion rates followed the land use changes, especially the transformation of forest to farmland. The results indicated that even slight land use change, from forest to farmland or vice versa, had a significant effect on regional soil erosion rates and sediment supply to rivers.