Soil Erosion Assessment Of Middle Reaches Of The Yellow River On River Basin Scale

The Yellow River is the mother river of China. The Yellow River Is the birthplace of Chinese civilization. Because of its special geographical location in history the Yellow river, especially Loess Plateau, become the serious soil erosion areas in China. Severe soil erosion not only destroys the ecosystem environment, but also produces large quantities sediments that silt up the downstream riverbed, and endangers flood control of the Yellow river. Therefore, conduction soil erosion assessment is very significant for the task of ecosystem management.Based on the areaof the middle reaches of the Yellow River, the paperuse a digital elevation model to analysis hydrological model in ArcGIS platform and to extract the border area in the middle reaches of the Yellow River basin. The transfer matrix and slope analysis method were used to study the different land types, vegetation coverage, etc.It uses the secondary and tertiary basin in the middle reaches of the Yellow River as the basic unit to analysis the soil erosion modulus of partition statistics.By using RUSLE model, it quantitatively discusses the different ecosystem types and the coupling relationship between vegetation coverage and soil erosion. The specific conclusions are asfollows:(1)Therelationship between soil erosion, vegetation coverage serious erosion and extremely erosion mainly corresponds to low coverage.(2)The way of land use effects soil erosion. The most serious erosion mainly distributes in the cultivated land on slopes. The slightest erosion mainly distributes in the regions of forestland.(3) When the slope is less than 8 °,theproportion of the very soil erosionand intensity soil erosion and is about 0.4%. When the slope is from 8 to 15 °, the proportion of soil erosion of intensity erosion and severe erosion is about 14.3%.When theslope is from 15 to 25 °, the type of soil erosion is very intensity soil erosion, and the proportion is about 2.4%. So the lower slope topography, the slighter soil erosion intensity.In this paper, the soil erosion, rainfall erosion force, soil resistance to erosion, topographic factor, cover factor and other factors related to soil erosion were calculated. Moreover, the processes of the establishment of soil erosion assessment indexes system and the application of GIS soil erosion assessment were discussed in thi s study. At the same time,the result soft his study can be directly used in the control of the Yellow river and offering providing the scientific basic to the rational utilization of land resources.