Analysis On Soil Erosion Of The Yellow Limestone Area In Northwestern Hunan Based On The USLE Model

Soil erosion is the important factors to make the land productivity decline and the ecological destruct. Limestone soil has a thin level and loose structure. It is easier to cause erosion Because of the poor economic conditions, the level of scientific research is low and the basic information is not enough lead the research of yellow limestone area of Northwestern Hunan not deep.Based on the soil erosion research achievements of the world’s scholars for many years, combine Remote Sensing and GIS technology into the Universal Soil Loss Equation (USLE), quantitative analysis the natural factors (Rainfall, Soil texture, Terrain, Vegetation Coverage) and human factors (Measures of soil and water conservation) which effect soil erosion in this area. The results have certain reference significance for the promotion of local soil erosion control and promote the local ecological restoration and reconstruction work.The results show that the soil erosion area accounted46.27%for the total yellow limestone area of Northwestern Hunan. The average soil erosion modulus is2478t/km2·a, Soil erosion is strong. Annual soil loss amount is213.86×105t. The area of Soil erosion is vast and the amount of soil erosion is large. So, the management for the soil erosion is necessary. The analysis results show that the amount of soil erosion in the proportion of woodland, grassland, shrub land and Dry land is the largest, and the proportion of other land use types is small. Soil erosion in the study region significantly affected by topography, the most serious area of soil erosion is where altitude of400-550m and Slope of15°～皛30°.The land use structure of the study area directly determines how much the amount of soil erosion, therefore, the key to reduce the amount of soil erosion in this area is to optimize the land use structure. For the area where causes large amount of soil erosion, we can use the reasonable measures of soil and water conservation to increase the vegetation coverage as much as possible. Using the plant roots to modify the lime soil in order to strengthen the permeability of soil, reduce surface runoff. Woodland and grassland should be allocated and transformed rationally to optimize the stand structure, better to play the function of forest in the water conservation.