Dynamic Change Analysis Of Water Erosion In Danjiangkou Reservoir Area Based On WEPP Model

Water erosion is an important environmental problem in China.The WEPP model provides a favorable scientific basis for water erosion simulation prediction and the formulation of soil and water conservation schemes.Most of the researches on water erosion in China focus on dot spatial distribution.In the paper,water erosion in Danjiangkou reservoir area is simulated and predicted in a regional scale.The text collects,manages,and integrates a large number of information from different data sources through GIS software.Including remote sensing data and soil data in 1997,2007,and 2017,and digital elevation model DEM data.Land management data are derived from the classification of remote sensing data;through the BPCDG model to arrange the weather data for the three months.Simulation and prediction of spatiotemporal distribution of water erosion in Danjiangkou reservoir area in 1997,2007 and 2017 by using WEPP model.And analysis of factors affecting water erosion.Get the following conclution.1.In the past 1997-2007,the water erosion intensity and total amount of water erosion in Danjiangkou reservoir area changed little.The tendency to rise first and then drop.The average water erosion amount is 10987200 t.In 1997-2007,water erosion is sloe mantle decreased,modulus is 3895.790 t/km2/a,the average soil deposition rate was 10959200 t.In 1997-2007,water erosion is slow mantle rising trend,growth rate of an average of about 0.275%,207-2017 is slow mantle decreased,average reduction rate is about 0.723%.In the period of 1997-2017,the flow of the jingle showed a continuous upward trend,with a total increase of 61231904m3,with an average annual growth rate of about 0.6138%.That in 1997-2017,since the construction of North Engineering Project in Danjiangkou reservoir,kite industry and the development of social economy and the harm of water erosion in Danjiangkou reservoir area;the South-to-North Water Diversion Project construction,in order to ensure the water quality safety,Danjiangkou reservoir Soil and water conservation and environmental protection measures to make the study area in 2007-2017 older water erosion reduction st flow increase.2.The northern and central Danjiangkou reservoir is in the mountainous and hilly areas,the gully is vertical and horizontal,and the south is in the alluvial plain.The study shows that the water erosion in the northern and central parts takes up 2/3 of the whole research area,and that of the southern part is only 1/3.In the middle and north parts,the runoff accounts for about 70.523% in 1997,and the rest years are all above 50%.This indicates that the difference of topography and topography will affect the occurrence of water erosion.However,due to the construction of water diversion project,the water storage in Danjiangkou reservoir has led to the decrease of runoff in the north and central parts of China.3.Based on the different slope,soil composition,climate and farming due to the simulation,found that natural factors and human factors changes will cause changes of water erosion dagger.In the form of GIS map output,the results of WEPP model simulation can be displayed more intuitively,clearly and more intuitively.