Quantitative Assessment Of Soil Erosion In Tumen River Basin By USLE

At present, china still faces serious soil erosion which has become a global environmental problem. The root cause of land degradation, chocked river and the loss of a large number of nutrient elements in soil is soil erosion. The frequent occurrence of soil erosion makes the land show gradual desertification, the area of cultivated land become less and grain production fall. As a result, the survival environment of human faces a huge threat. Though the research on soil erosion carries out later than it in some other countries, it develops rapidly in recent decades. Soil erosion model can make the study of soil erosion transform from the qualitative descriptions into quantitative evaluation in order to govern soil erosion.Universal Soil Loss Equation which is a useful tool for evaluating soil erosion is most widely used erosion model. With the development of GIS, GIS are increasingly used in the study of soil erosion. The combination of GIS and Universal Soil Loss Equation makes the quantitative evaluation of soil erosion achieve in the watershed scale. Making use of spatial analysis and grid data computing capability of GIS, we can calculate the amount of soil erosion in watershed. We can find out some regions needed to govern through the visualization of different erosion intensity in the watershed. All of these can provide a reasonable basis to carry out water and soil conservation measures.Based on GIS and USLE, according to the actual state in Tumen River Basin, choosing the reasonable methods to calculate R,K,LS,C,P factors in the USLE, the soil erosion of Tumen River Basin in 2007 was evaluated. The status of soil erosion within the watershed was analyzed, and analyzed the characteristic of soil erosion of different grade, the status of soil erosion of different land use. These analysis could provide a scientific basis to control and govern soil erosion in Tumen River Basin.