Spatial Temporal Dynamic Change And Driving Factors Of Soil Erosion In Chongqing

Chongqing is located in the southwest of our country and the upper reaches of the Yangtze River,the environment is complex,and it is also the important node in China "The Belt and Road" land access,strategic significance.The soil erosion of the five functional areas are different,the soil erosion intensity affects the development focus of the five functional areas,so this paper based on their differences in the environment of the five functional areas,respectively,choose 1995,2005 and 2015,the three time node representatives the time before Chongqing became the municipality city,the mid-term of the Three Gorges project and the current situation of Chongqing,through the interpretation of remote sensing,spatial analysis,data statistics,to study the trend of land use change in five functional areas of Chongqing,spatiotemporal dynamics of soil erosion between the five functional areas,the variation of each functional area,and the driving factors of soil erosion,the main conclusions are as follows:(1)Analysis on calculation method of soil erosion.By comparing the calculation methods of each factor in the USLE model,the calculation method used in the study area is obtained,and applied to the estimation of soil erosion quantity,and the soil erosion amount in the five functional areas is obtained.(2)Land use conversion analysis.By analysis the land use situation of 1995,2005 and 2015,the land use conversion of 1995-2005 and 2005-2015 was analyzed,and the change trend of soil erosion in 1995-2005 and 2005-2015 was inferred.The soil erosion will deteriorate in the functional areas which the main land use transfer direction is dry land,the soil erosion will be inhibited in the functional areas which the main land use transfer direction is forest land and construction land.(3)Comparative study on the dynamic change of soil erosion in five functional areas.From the perspective of dynamic change of space,the New Urban Development Area is the most serious of soil erosion among the five functional areas in 1995,soil erosion of the Urban Core Functional Area is the least;Ecological Conservation Development Area of Northeast Chongqing is the most serious of soil erosion among the five functional areas in 2005,soil erosion of the Urban Core Functional Area is the least;Ecological Conservation Development Area of Northeast Chongqing is the most serious of soil erosion among the five functional areas in 2015,soil erosion of the Urban Core Functional Area is the least.From the dynamic change of time,the soil erosion status of the five functional areas in the 1995-2015 year period showed a trend of increasing first and then decreasing.There are two functional areas of abnormal,both had the trend of sustained reduction:(1)Urban Core Functional Area.Intensive human activities,the scale of construction land continues to expand,land reduction and other factors cause the result.(2)the New Urban Development Area.It has not been super strength development,the natural environment can be maintained,the government implemented a large number of environmental policies and other factors cause the result.(3)Analysis on driving factors of soil erosion change in Chongqing.Through the principal component analysis of each driving factor,the three principal components are extracted,which are the level of economic development,the level of resource demand,and the natural conditions.