Integrated Modeling Approach to the Response of Soil Erosion and Sediment Export to Land-Use Change at the Basin Scale

Abstract

Land use determines the erodibility and hydrological structure of land units. Grid-based modeling is an effective approach for handling the spatial heterogeneity of basin characteristics, such as land use, soil, rainfall, and topographical information. The reliability of simulation results from erosion models is circumscribed by considerable spatial variation of numerous 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 Lushi Basin, primarily in Henan, China, were analyzed by comparing historical land use maps from 1990 and 1995. By comparing the responses of four selected storms that were simulated under conditions indicated by these two land-use maps, the average erosion rates were found to increase from 1989 to 1996. The increase in the average erosion rates followed land-use changes, particularly the transformation of forest to farmland. The results indicated that land-use change has a significant effect on regional soil erosion and sediment supply.