Sanjiang Plain Wetlands Change And Driving Forces In Recent60Years

Sanjiang Plain is located in our country’s northeast of Heilong jiang province. It is also the largest wetland area of China. Since the reform and opening-up, with the economic development and immigrants arrive in large numbers. People reclaims the cultivated land so frequently that a series of phenomenon of ecologic destruction. Therefore, the wetlands get more and more emphases and protection from government. This text mainly from influencing the quantitative analysis of wetlands lost of Sanjiang Plain and find out the important factor which causes loss of wetland. In order to provide the reliable foundation for wetlands management and protection in Sanjiang plain, on the basis of remote sensing images with ArcGIS and the geographical detector to through the quantitative analysis of the wetlands loss of sanjiang plain in nearly60years, put forwards some countermeasure and suggestion for the variation trend of the wetlands loss and get the following conclusions:(1) sang jiang plain wetlands loss is mainly occurred during1954-1896. In the study area wetlands lost the main direction of transformation is plow during60years. From the view of focus shifted, the center of gravity moves3.7km to the east during1954-1986, and move3.708km to south; and to the west about1.9427km ande to the south185.4m during1986-2010, so we can see that the wetlands of sanjiang plain moves to the southeast.(2) this thesis analyzes the loss of driving factor in the wetlands of sanjiang plain by using the method of superposition analysis, we can see it clearly that the loss of wetlands in this two periods is mainly occurring in an incline of0-5degrees, and an altitude of0-140m, We can make a conclusion from analyzing landscape, soil, river, annual temperature and annual precipitation that the loss of wetland is mainly occurring in river landform, especially in flood plain and scroll that is the most and less in river terrace, igneous landscape and karst landscape. Different population density and the area of the loss of wetlands in different GDP regions during1986-2010shows that the area of the loss of wetlands which is in less population density and low level of GDP is larger.(3) Without the function of social factors during1954-1986, in the natural driving factors, altitude, topography, slope and soil greater have great influence on wetland loss. And social factors involved during1986-2010, and their respective influence is altitude>slope> soil>pulation density>the distance from settlements>GD(4)1954-1986The order of interaction between social factor (PD,H) according to the explanatory power likes this:mean annual temperatures∩altitude=soil∩altitude=rivers∩altitude=(40%)> annual precipitation∩altitude(39%)> aspect∩altitude (38%).1986-2010The order of interaction between social factor (PD,H) according to the explanatory power likes this:population soil∩altitude (36%)> rivers∩altitude(34%)> Population density∩altitude(32%)> population density∩soil (30%)> GDP∩annual soil(28%).