The Risk Research Of Soil Erosion In Rao River Basin

Based on ArcGIS,3S technology and assist to other related software, accordingto TM images, DEM image, soil data, rainfall data and other information, this articlecalculates and extracts each factor of the Universal Soil Loss Equation in GIS atfirst,then gets each factor’s thematic maps of Rao watershed in2000and2010.Second, thematic maps of each factor are even multiplied by USLE equation based oncomputing of raster in GIS. Finally, after considering the distribution of histogramand research of others, the grid diagram is classified based on risk. Then the map ofrisking level of soil erosion of Rao watershed is got.According analyzing and calculating the map of risking level of soil erosion,risking level of Rao watershed soil erosion is concluded. All are in the micro-level,mild erosion risk level. Intensity and cumulative erosion above intensity occupied1.61%of the area in2000, while the2010is1.76%.The area occupied by intensityand cumulative erosion above intensity had a small margin improvement bycontrast.The main reason is that the pole strength erosion rised from0.23%to0.83%.Therefore, it is necessary to take measures to control the erosion area of thiserosion level continue to increase. Regions of soil erosion of pole should beprevented and remediated emphasisly. It should be included as a key area of soil andwater conserving and planning. By comparing the use of land of Rao watershe in2000and2010, woodland and residential areas increased, but paddy fields and dryland reduced, especially the dry land reduced by51.78%.Finally,the relationshipbetween soil erosion of risking level and slope is studied, we get: from moderateintensity to strong intensity and extremly strong intensity, most of them distributedin8°~15°,15°~25°,25°~35°slope zone. It can be seen that with the increase of theslope, the erosion is easily to prone. The primary segments of strong intensity andextremely intensity are in15°~35°slope of the band. It should be focused to betreated during erosion controlling work in the future.