Quantitative Assessment of Hydraulic Erosion Based on Data Mining of RS and GIS

RUSLE, Revised Universal Soil Loss Equation, was used to estimate the average hydraulic erosion modulus of study area in four phases, which were 1976, 1988, 2000 and 2005 respectively. According to the classification standard of hydraulic erosion intensity, hydraulic erosion moduli were classified into different grades. Then, the hydraulic erosion of study area is evaluated dynamically. The study results showed that: the hydraulic erosion in the study area was in serious condition, which especially occurred in some areas with higher elevations, little vegetation cover or great slope. During all erosion levels, the intense erosion was in the first place, the intensity and the extreme erosion was second, tiny erosion and light erosion followed. From 1976 to 2005, the area, where the hydraulic erosion intensity was unvaried, was dominant, and where erosion intensity varied, distributed in area where vegetation cover and slope changed. The area range at every level was little, and the trend was upward. The total trend of hydraulic erosion in study area was upward, but the rate was downward.