The Investigation About The Relation Between Lake Evolution And Vegetation Distribution Of Muping Lake

The Dongting lake located in middle reach of the Yangtze River which is the second largest lake in China. It has many important functions to the Yangtze River,such as maintaining equilibrium of transportation ,scour and sedimentation of mud,adjusting flood accumulation and drainage,slowing down the bed changes of lake and River,decreasing flood disaster and so on. Since early stage of the 20's century, the heavy sedimentation has resulted in rapid shrink of Dongting Lake's area and serious weaken of Lake's adjusting function about flood draining and accumulation.At the same time,because of mud deposition,lake beach enlarging will develop.If the lake beach become silt up the water level will rise up correspondently. So the condition of lake beach and the relation between water lever and elevation of lake beach restrict the growth, cultivating, distribution and output of vegetation. The nonuniform of mud deposition influences the growth and distribution of vegetation. Moreover vegetation has tangible function to obstruct flow and promote deposition. Therefore the growth of vegetation and the mud deposition are prerequisite , causing and effecting each other. There is a vicious spiral vicious circle.There is much relativity between mud deposition and lake beach's vegetation.The direct consequence of sedimentation includes: 1, the area of Dongtin Lake was smaller and the function of wet land was much weakened. 2. the trend of Epidemic diseases of schistosome and perch and food source of migrant bird was affected; 3. water resources contaminate was more serious.So the aim of this investigation has very important scientific significance and practical value to synthetical regulation, natural resources exploitation and sustainable development of Dongthu Lake area.Taken Muping lake located west Dongting lake as an example,based on geographic information system (GIS) and remote sensing (RS) ,the relationship between evolvement of scour and sedimentation and distributing of the vegetation is discussed in this paper.From topographic maps in 1975 and 1995,the digital elevation model (DEM) are built,the quantity and space regulation of the change of sediment deposition and erosion are discovered consequently.This paper introduces TM remote sensing image's treatment and interpretation method.Through interpreting several years TM images,the developing character of...