Soil erosion risk was graded using results from an analysis of soil erosion characteristics based on Geographical Information System ARCGIS.The process of grading the potential danger of soil erosion and its spatial distribution is straightforward in ARCGIS.Firstly

soil erosion modulus is estimated using a water erosion model

and maps of soil density and soil horizon thickness are derived from detailed soil survey data.Then

the temporal character of soil loss is calculated using soil erosion modulus

soil thickness and soil density.Next

in line with Ministry of Water Resources.classification standards

the potential danger of soil erosion is divided into five grades and an index of soil erosion potential danger( SEPDI) is established.The SEPDI has been tested in a case study in Fengdu County in the Three Gorges area

with ARCGIS used to assess erosion potential distribution characteristics.