Spatial Distribution of Vulnerability to Extreme Flood: in provincial scale of China
Abstract. Flood (EF) disasters in China are characterized by large influence range, high frequency, strong burst and uneven distribution in time and space. Once the EF disaster occurs, it will pose a great threat to the people’s life safety, economic, natural and social environment. Compared with the hazards and exposure factors of EF, the vulnerability of disaster regions shows great differences due to China’s vastness and complex social and environmental background of disasters, which leads to less large-scale study at provincial-level on EF vulnerability. This study calculated the vulnerability to EF from the favorable and unfavorable factors of flood resistance of four aspects including life, economy, environment and society. The Cloud-improved Entropy Method is used to calculate the index weight, and the Fuzzy Variable Theory is used to calculate the comprehen-sive vulnerability grads. The vulnerability ranking of 31 provinces or regions in China was made according to the differences of population, social structure, economy and environment among these regions. Furthermore, synthesizing disaster science and geographic mapping, the spatial distribution map of vulnerability to EF in China was generated, which shows that vul-nerability to EF in most regions of China is in “moderate” or “severe” grade. The spatial distri-bution of the EF risk vulnerability shows (1) a decreasing trend from the regions with high pop-ulation density to regions with low population density, (2) a decreasing trend from economical-ly developed regions to economically backward regions, (3) a decreasing trend from the eastern coastal regions to the central agricultural provinces and then to the southwest, northwest and northeast regions in China. The outcome of this study maybe one of the first efforts providing research database for vulnerability to EF in large scale of China, and it is useful for future regional research and risk management.
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