Study On Soil Erosion In Ansai County Of Shaanxi Province

Ansai country in Shanxi province is located in the plateau of the northwest inland,is located in the Ordos basin edge.Its unique characteristics,terrain slope and summer rainy climate conditions,and severe agriculture and human activities,all lead to serious soil erosion in the region.Soil and water loss can lead to land degradation,soil fertility decline,arable land decrease.And it hinder the sustainable development of the society too.Become the soil erosion for the loess plateau is so serious,soil erosion dynamic observation condition is urgently needed.For the soil condition of the Shanxi province,this paper uses Arc GIS software to research,and using WEEP software analyze the factors of the rill erosion which is the main way erosion of Ansai country.The soil erosion macroscopic observation need 3S technology,using elevation data and Arc GIS software to analyze the DEM data that the resolution is 30 meters.Then Using Arc GIS software to extract the no depression basin,the flow direction,the cumulative flow,lattice vector quantization river,generate river network connection,generate the catchment basin,determine the drainage basin,basin mainly classification and each watershed gully density extraction.Then analyze every watershed gully density.Then compare the watershed gully density with the standard(SL190-2007)of the gully erosion classification standards,which is divided into mild,moderate,strong erosion strength,very strong and intense all levels,and results show that the soil erosion of each basin is very serious,belong to intense level.Because rill erosion of the sediment content is about 70% of the whole river basin,the rill erosion is the main soil erosion on the loess plateau.The WEEP software is a water erosion model which is mainly used to simulate rill erosion.Input the data of the 2015 climate of Ansai country,soil characteristics,different slope,different slope length and different tillage farming into the WEEP software to simulate the soil erosion.Under the same conditions,the smallest soil erosion is the grassland farming area,then winter wheat cultivation area of soil erosion is greater than the grassland farming area,soybeans and corn crop cultivation area of soil erosion is approximately the same and is greater than the soil erosion of winter wheat crop farming area,finally,fallow cropping area without any crop cultivation area of soil erosion is the largest.Therefore,the soil erosion of vegetation protection soil is far less than the fallow crop protection farming area,therefore,the crop protection is very important to control soil and water conservation.