Analysis Of Land Use Cover Change And Its Influence On Flood Vulnerability In Dongting Lake Region

Dongting lake Region is the important grain base in our country, flood disasters occur frequently and cause great damage to economy and society. Flood disasters are closely related to land use and cover, land use and cover change affects the vulnerability of hazard-affected bodies. Therefore, to study the regularity and feature of land use and cover change and its influence on flood disaster vulnerability contribute to the improvement of the ecological environment of Dongting Lake, and to achieve the purpose of reducing flood disaster vulnerability through scientific protection and utilization of land resources.Taking Dongting Lake Region, about19cities and counties in Yiyang city, Yueyang city, and Changde city as the research objects. Using ENVI4.8, GIS software for1987,1998and2008the third phase of remote sensing image data in combination with statistical yearbook, historical datum and other auxiliary materials for information extraction, using the SPSS and EXCEL data analysis software, analysis of Dongting Lake land use/cover change characteristics and regularity of time and space, the results showed that:from1987to2008, different degrees of land changes have taken place in Dongting lake Region, cultivated land and unused land and grassland decreased, construction land, forest land and water Region increased; Large amount of construction land and the cultivated land change, and its change speeding, the grass and water change smaller, change speed is slower; The change of land use degree is big, land use types change from low to high level development.Using the method of analytic hierarchy process (AHP) and the percentage of quantitative parameters to determine the vulnerability of hazard-affected bodies and make parameters as the weight value of various land vulnerability, draw the space distribution of vulnerability, build the Dongting Lake flood disaster vulnerability assessment model, and using the comprehensive evaluation model of vulnerability to do research on the Dongting Lake typical regional vulnerability, the results show that all kinds of the vulnerability of hazard-affected bodies have different parameters, construction land is the largest, followed by farmland, then is the waters and woodlands, and both of them have the similar size, finally is unused land and grassland; In1987-2008flood vulnerability value presents the increasing trend and the accelerating speed; Abdominal region is the high or higher vulnerability Region; The water Region is the medial vulnerability Region; Because of the high altitude beach Region and unused land are the low economic vulnerability Region; Spatially, vulnerability has regionality, abdominal region vulnerability value is big, while the faraway Regions is small; As the time goes, the vulnerability value increasing.