Extraction of RUSLE-LS Factors Using DEM data and GIS Techniques;

<Abstrcat> This paper introduces the model of Revised Universal Soil Loss equation (RUSLE) and the algorithm of its each factor.

By using GIS and RS techniques and RUSLE,the rainfall erosivity(R),soil erodibility(K),vegetation and management factor(C),and slope length and steepness factor(LS)around Hangzhou Bay of Zhejiang Province,China were calculated to make a comprehensive sensitivity evaluation of soil erosion in the study area.

The amounts of soil erosion and retention and their spatial distribution of the region were studied utilizing universal soil loss equation; and the techniques of market value, opportunity cost and shadow engineering were utilized to evaluate the value of soil retention function.

Soil loss was predicted and risk areas of soil erosion were identified in Dahongshan Iron Mine at Xinping of Yunnan province by means of combinin geographical information system(GIS) and universal soil loss equation(USLE).

Based on the multi-uncertainty characteristics of the information in soil, topography, raining, vegetation and management technology, the blind number method in unascertained mathematics is applied to describe and treat the characteristics of parameters in the Universal Soil Loss Equation (USLE).