Based on geo-statistical principle and semi-variability theory

this paper quantificationally studied the spatial variability of soil factor for modeling of soil erosion by water in GIS

comparing the accuracy of different interpolation methods

including IDW，Spline and Ordinary Kriging. The results showed that the spatial correlation of regional soil coefficient of soil anti-scourability was moderately

the nugget-to-sill ratio was 32. 29%，while the spatial correlation of steady infiltration rate，collapse velocity and shear strength was very strongly correlated，the nugget-to-sill ratio was 13. 19%，11. 61 % and 12. 98%respectively. In a word，taking account of MRE

RMSE and interpolation results

Ordinary Kriging interpolation was the best one

which represented the spatial characteristics of soil factors well and can be better used in regional soil erosion model in view of data requirement. To Ordinary Kriging

the lag step of the steady infiltration rate was 30000 meters

and the semi-variance theory model was exponential model whereas the soil coefficient of restitution

collapse velocity and shear strength was 50 000 meters respectively

and the semivariance theory was Gaussian Model. Besides

owing to the spatial distribution of soil type ranging from north to south

each index showed clear zonation differentiation character.