The Study of YiHe Basin on Soil Erosion Simulation Using WATEM/SEDEM Model

【摘要】：正With the support of remote sensing and GIS technology,the mean annual soil loss and the mean annual transport capacity in YiHe in 2000 were calculated by using WATEM/SEDEM model,and a soil erosion map was drawn according to the soil erosion intensity classification criterion.Based on these,the spatial distribution of water-and-soil loss and transport capacity in 2000 was analyzed.The analysis results of soil erosion situation show:the soil erosion area was 5184508 km~2 in YiHe basin in 2000,42.49%in the total amount of soil erosion,and moderate levels of erosion above had revealed the degressive tendency in YiHe basin.The mean soil erosion modulus in this basin was 30.06 t·km~(-2)·a~(-1),belonging to mild erosion.The analysis results of sediment transport capacity show:the mean annual transport capacity was 12.92 t·km~(-2)·a~(-1) in YiHe basin and the transport capacity of unused was the strongest,54.4 t·km~(-2)·a~(-1);different types of land use revealed sharply differences of sediment discharge.Erosion occurred mainly in tillage land and forest land,83.78%in the total amount of sediment discharge.It may relate to,with the most in the mountainous watershed,the main land use types for the slope.It should strengthen effectively the management of land use types,adopting returning the grain plots to forestry and forest-grass to contain soil erosion within the basin in the future.