Abstract:

Taking Nüerzhai small watershed which lies in Wuling Mountain of middlelower Yangtze River as study area,this paper calculated some factors such as rainfall erosivity and soil erodibility based on data observed and sampling on the spot in watershed.By using geographic information system(GIS)and the revised universal soil loss equation(RUSLE),the soil erosion intensity and its relationship with land use types and altitudes in watershed were studied.The results show that the average soil erosion intensity in the watershed was 78844 t/（km2〖DK1〗·a）,which was in the category of feeble degree erosion.9518% of watershed was below the category of slight degree erosion and only 119% of watershed exceeded the category of strong degree erosion.In different land use types,soil erosion intensities of cultivated land and orchard were bigger than the others.They were in the category of moderate degree erosion.Forest land was in the category of feeble degree erosion except for bamboo grove,which was in the category of slight degree erosion.Cultivated land,orchard and bamboo grove were the main land use type for preventing soil and water loss in future.In different altitudes,64.42% of the total soil loss occured in lower altitudes(200～400 m).This region was the major region for preventing soil and water loss.The study provides an example for applying RUSLE to assess soil erosion in Wuling Mountain area and offers useful references for preventing soil erosion and making decision for watershed management