Impact of Land Use Change on Runoff and Sediment Yield

The impact of Land Use and Land-Cover Change (LUCC) mainly on annual runoff yield, in this study through scenarios simulation of Lushi basin using SWAT(Soil and Water Assessment Tools), the impact of LUUC on annual runoff yield and sediment yield were analyzed, and stressed on the forest's impact on runoff yield. The subbasin upper to the Lushi hydrologic station in the lower reach of the Yellow River basin, the daily precipitation data of 24 rainfall station and the climatic data in this area from 1992~2000, soil type and the scenarios of the landuse, all of these data were inputed to the SWAT (Soil and Water Assessment Tool ) to simulate the impact of LUCC on the yield of runoff and sediment. The simulated results indicate that forest will increase the runoff yield and decrease sediment yield, grassland reduce runoff yield; with the increase of land use of agriculture the sediment yield will increase correspondingly; the least impact of LUCC on runoff yield was found in normal mean precipitation year, with the increase of the rain rate, impact of the basin condition on the runoff and sediment yield will be reduced.