Simulation Studies On The Sloping Land Soil Erosion Of Miyun Reservoir Surrounding

China is one of the most serious soil erosion Country in the world, and the proportion of Chinese soil erosion area is 38.2%. Because sloping filed occupies heavy proportion, studying the influence factors of erosion, monitoring and managing them have been a focus of the world. Miyun Reservoir is the biggest drinking water source of Beijing. The soil erosion and land-use pattern of mountains around the reservoir decide the water quality of Miyun Reservoir. Being the thin soil layers, low precipitous mountains and hills with frequent agricultural economic activity at the upper reaches of Miyun Reservoir, soil erosion of here is comparatively serious. After field surveys to Miyun Reservoir surrounding areas, Miyun farmland cinnamon soil was selected to be the study object based on the characteristic wide sloping filed areas. The cross-experimentation adopted the advanced simulated rainfall equipment and ICP-MS mass spectrum analyzing technology and atomic absorption analyzing technology, and designed three different surface conditions, three kinds of rainfall intensities and five kinds of slopes. Compared with test result of field sample, soil erosion conditions of this reservoir surrounding areas were deeply studied. Combining with the related analysis result of indoor and outdoor, erosion and nutrient loss reference models under experimental condition were set up, and the soil erosion and nutrient loss conditions of typical drainage area that were chosen have been predicted and appraised by GIS technology. All the purposes were offering scientific basis for sloping fields around the reservoir to reduce its soil erosion and nutrient loss fields, optimize their hillside surface land use, improve the output of the hillside fields crop, and effectively adjust and control them. At the same time, this study provided quantificational reference to other investigator to research the soil erosion of different sloping fields. Main conclusions as follows,(1) The simulated test under the same rainfall intensity, slope and rainfall duration showed that, the values that water and sediment of runoff and splash erosion infected by surface condition separately expressed that bare land lower than the surfaces that coved with straw and turf, and straw mulching