There are so many environmental background factors in soil erosion region

such as slope

land use

DEM

etc.However

not all factors play a role in soil erosion equally.Problem about how to identify the main factors in water erosion in China are discussed.Firstly

according to the conditions of study area

environmental background factors that are translated into 100m×100m data format in GRID are choosen.Secondly

degrees for each factor according to the difference degree to soil erosion are set.Each environmental background has different degrees.Thirdly

with the MGE and GIS

we resample in study area in China in equal distance

so that we get lots of samples that can illustrate the study area.Then according to actualsi tuation of each sample

values are put into each sample in line with degrees in the step 2. Finally

all datum are put into software package SPSS for factor analysis.Through factor analysis

the main factors can be choosen.This model is based on expert knowledge and object analysis

overcoming the man-made factor and showing the situation objectively.