Impacts of Land Use on Soil Erosion in Karst Mountainous Area ——A Case Study in Shibanqiao Catchment in Guanling county,Guizhou Province

AbstrcatSoil erosion is closely related with land use.But there is no generalized rule in the whole world.Soil erosion presents very differently in Karst area in relative to other regions.Taking a small catchment in Karst mountainous area as a case,the study on relationship between soil erosion and land use type,slop distribution pattern and altitude distribution pattern of land use was carried out.Such conclusions were drawn:the biggest percentage of area exposed to soil erosion in each kind of land use was grassland,and woodland, cropland,land difficult to use,built up and paddy field in sequence.Except for paddy field,there was a threshold in the control of vegetation cover rate on soil erosion.It was 20%～60%.While the severity of soil erosion nearly intensified with vegetation cover rate.There was also a threshold in slope pattern and altitude pattern of land use distribution,the former was 15～25°,and the latter was 1 485～1 505 m.