Assessment of Soil Erosion Sensitivity Based on Environment Background Analysis

Soil erosion seriously threatens the ecological environment across the world, and much attention has also been devoted to this problem in recent years. The objective of this study was to assess soil erosion sensitivity under its environment background on large scale. Supported with GIS and remote sensing technologies, the relationship of soil erosion intensity status and its environment background was comprehensively analyzed, which consisted of slope gradient, altitudes, vegetation cover, surface material, land use and precipitation, then the soil erosion complicated indexes of natural factors was calculated, and the soil erosion sensitivity was assessed and derived using spatial principal components analysis. The result of soil erosion sensitivity was divided into five levels: no sensitivity, low sensitivity, medium sensitivity, high sensitivity and extreme sensitivity. The approach was applied to a case study of Hubei Province, Central China. The assessment results indicated that the soil erosion sensitivity was at low level for the study area as a whole, 30.6% of the total land area under no soil erosion sensitivity, low and medium erosion sensitivity was with an area percentage of 55.8%, while high and extreme sensitivity was relatively limited, with an area percentage of 13.6%. Based on the analysis with environment background, high soil erosion sensitivity mostly occurred in the slope gradient between 8 to 15deg, at altitude from 150 to 500 meters, as far as land use is concerned, soil erosion sensitivity is highest in dry land, especially in areas with surface material vulnerable to erosion. Results of the study may provide an important basis for environmental protection and ecological reconstruction.