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The flood disaster is one of China's major natural disasters. Subtropical monsoon zone in Chongqing, by alternating impact of the southeast and southwest monsoons, and frequent heavy rain in the summer, the terrain is tilted on the whole by the north and south to the Yangtze River valley, undulating terrain, as well as by the impact of the Sichuan Basin, the pattern of many rivers in water system clouds, formed mainly in the Yangtze River at the same time to bring together the many tributaries of the basin surrounding mountain asymmetric water system to the heart, making Chongqing annual flood disasters frequencies up to 2 to 4 times a serious threat to the safety of life and property of the people. As a non-engineering measures, flood disaster risk assessment, the assessment of Chongqing flood damage, flood prevention and relief, land use and development is of great significance. This article discusses the floods basic principles of risk assessment and the main content; presents and analyzes used the pros and cons of the flood disaster risk assessment method; general steps of the basic theory of fuzzy math and fuzzy comprehensive evaluation, fuzzy comprehensive evaluation method combination of flood risk evaluation, to make full use of the advantages of fuzzy comprehensive evaluation method in the evaluation of flood risk; introduces the basic features and functions of the GIS and GIS flood disaster risk assessment; according to the principles of flood risk assessment, indicators principle, evaluation methods, and the actual situation of the study area is selected, select the evaluation of flood risk, flood disaster risk evaluation index system in Chongqing; constructed Chongqing flood risk based on fuzzy comprehensive evaluation method, fuzzy comprehensive evaluation model; flood disaster the risk fuzzy comprehensive evaluation model the input GIS, operation processing, the resulting flood risk maps in Chongqing. Flood risk figure shows, Chongqing there are significant differences in the risk of floods: high-risk areas, the higher risk areas are mainly located in Chongqing, western, central, and most of Liangping County, northeast, Kaixian and Wanzhou District; low-risk areas, lower risk areas are mainly distributed in most parts of southeastern Chongqing Chengkou County, northeast of Chongqing, Wuxi County, Wushan County, Fengjie and Yunyang County, the eastern region; same level flood disaster risk in addition to the large centralized distribution , but also showed differences in binding of the natural environment within the regional socio-economic factors patchy scattered distribution of high-risk areas, a higher risk of this characteristic is more obvious, the embodiment of the dual attributes of these are floods, Chongqing results.
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