Study On The Vulnerability Assessment Of Flash Floods In Xichang City

Flash flood is the fast and powerful mountain streams, seriously threat to thesafety of people’s lives. There is complex environmental background in Southwestmountain towns, mountain floods and other disasters broke out frequently. With thesocial and economic development and intensity of human activities increasing, Flashflood are increasingly serious, becoming one of the main factors limiting thedevelopment of mountain towns. Vulnerability of Flash flood is the managementresearch of flash flood disaster risk. It is from the social point of view to analyze thepossibility of hazard bearing body for disaster response or size. But this work is notyet a unified evaluation methods and technical means. Therefore, to solve thisproblem, this study starts from the two aspects of the population and the economy,used remote sensing and geographic information technologies, researched to obtainthe basis of data and thematic data of the mountain flood, built the western town ofmountain flood vulnerability assessment system. Then selected Xichang city as thestudy area, conducted the single factor of mountain flood disasters and integratedvulnerability assessment studying, completed a vulnerability assessment gradingzoning. The main findings are as follows:1. This study has defined the types of evaluation and the evaluation units, identifiedurban mountain flood vulnerability assessment indicators, carried out a detailedsurvey of remote sensing in study area. And this study has obtained the basic data ofthe urban population and financial conditions, established the mountain flood baseand thematic databases for flash floods disaster, and provided the support of theunderlying data for vulnerability assessment.2. This study selected nine evaluation factors: population density, educationalattainment, age structure, distance to hospitals, type of industry, the output value ofassets, the output value of resources, structure, numbers of layers. And a mountainflood single elements of population and economic vulnerability evaluation system wasconstructed. The gray relational and information entropy model were used to conductmountain flood disasters single elements vulnerability assessment. Then the results ofpopulation and economic vulnerability assessment in study area were distinguished ingrades.3. Based on a single factor vulnerability assessment, this study built a comprehensivevulnerability assessment model, conducted the mountain flood vulnerabilityassessment and hierarchical divisions in study area. The results were consistent withsurvey data and the actual situation. And the results verified the feasibility andrationality of the model and technology in this study.