Typhoon Disaster Scenario-based Risk Assessment Studies

Located in the fluvial plain of Yangtze estuary delta with low elevation,Shanghai has access to both river and sea. It is a oceanic hazards Hotspot in China and suffered by strong typhoons which bring Shanghai major social and economic losses, these typhoons impact city's normal operation.The paper chooses one small region to research senario-based typhoon disaster risk spatial distribution.On the base of systematically analysis of international and national typhoon disaster risk assessment's research progress, developes senario-based typhoon disaster risk assessment's methodology. The paper takes the areas of Yangpu District Fululi neighborhood committee as example, carries out a given probability-based typhoon risk assessment, draw exposure and risk spatial distribution, analyses the factors of losses distrbution irregularly. The paper evaluates the possibility of destructive typhoon attacking Fululi and losses objectively to provide a solid theoretical basis for government to reduce disaster and draw up contigency planning.The paper firstly illustrates the conception of disaster risk, after that, the paper reviews the research progress of typhoon disaster risk assessment. Secondly, the paper compute typhoon maximum wind speed-annual exceedence probability and process of rainfall-annual exceedence probability using 1949-2007 Shanghai typhoon meteorological datum, and then combines the minimum annual exceedence probability and field measurements, survey results to assessment structures exposure and risk. The paper analyses hazards factors briefly, and raises some regional stragedies proposals. Finally, the conclusion and the orientation of research for future are discussed.The main conclusions are as followings: (1) In the typhoon impacted Shanghai nearly 60 years, the exceedence probability of maximum wind speed 17.2m/s is 10.9%. The biggest accumulated rainfall of Shanghai is 306mm, and its exceedence probability is 1.8%. (2) On the scenario of maximum wind speed's exceedence probability is 10.9%, there are 52 structures will have loss in Fululi. On the scenario of accumulated rainfall's exceedence probability is 1.8%, the deepest water level is 0.61m, and there are 129 structures are inundated. (3) On the scenario of maximum wind speed's exceedence probability is 10.9%, there are 52 (15.29%) structures have wind losses, and 47 residence structures have wind losses, occupating more than 90%. On the scenario of accumulated rainfall's exceedence probability is 1.8%, there are 115 (33.82%) structures have rain losses. All the structures are residence structures. These losses are all acceptable or tolerable, however some emergency plans are essential.