Study On Risk Assessment Of Typhoon Storm Surge And Emergency Traffic Evacuation

Typhoon disaster is a meteorological disaster which often happened in China’scoastal and some inland regions, it is one of the world’s most severe natural disasters.The storm surge disasters caused by typhoon are the first of China’s marine disasters,which often result in significant casualties and property lossess.Evaluating the risk of typhoon storm surges to identify high-risk areas,predicting the impact of typhoon storm surge to determine the submerged area anddepth, will provide important guidance on disaster prevention and mitigationplanning and emergency resource allocation. The research on theory and methods oftyphoon storm surges is helpful on transferring the affected population to safe areasmore quickly and effectively, thereby reducing the casualties and property lossesscaused by typhoon storm surge disasters.In this paper, a system for risk assessment, impact prediction and emergencytraffic evacuation is proposed, through studying the quantitative risk assessmentmethods and the impact forecasting techniques of the typhoon storm surge disasters,the theory and methods of emergency traffic evacuation.In the section of risk assessment for typhoon storm surge disasters, the hazard,vulnerability and exposure of the typhoon storm surge are consideredcomprehensively to propose a risk assessment index system. Each index is quantifiedaccording to historical statistics and other data, then an overlay analysis based ontheir weight is carried out using the spatial analysis function in GIS, and the risk ratezoning of the typhoon storm surge disasters is obtained. The area along the coast ofZhejing Province is selected as an example to have a case study on risk assessmentof typhoon storm surge disasters.In the section of impact prediction technology for typhoon storm surge disasters,the storm surge prediction model ADCIRC (ADvanced CIRCulationMulti-dimensional Hydrodynamic Model) is used to analyze the flooded scope anddepth of the typhoon storm surge disasters. Based on the principles of ADCIRC,including the control equations, the wind field model, the wet and dry mesh methods, the forecasting processes and methods are researched. The Taizhou City of ZhejiangProvince is selected as an example to have a case study, the DEM data in30maccuracy are used to model the study area, the relevant data of typhoon ‘Rananim’are used as the input parameters of the ADCIRC model, and the submerged rangeand depth of Taizhou City in the typhoon ‘Rananim’ are obtained.In the section of theory and methods study for emergency traffic evacuation, thenumerical solution and the microscopic traffic simulation methods are combinedtogether, the emergency traffic evacuation models are solved numerically, theevacuation processes are simulated microscopicly using the the microscopic trafficsimulation software VISSIM, the numerical results and the simulation results areanalyzed comparatively to make the study closed to the actual situation. Based onthe theory of the cell transmission model (CTM), the evacuation route selectionmodel is built with the objective function to minimize the total travel time. Thecontraflow operation model is built with the objective function to minimize the totaltravel time, which is used to determine the best reverse lane position. The stagedevacuation model is built with the objective function to minimize the weighted totaltravel time, which is used to optimize the network at the starting point. Case studiesare carried out for each evacuation model, the MathProg and Lp_solve is used tohave numerical solutions for the models, which are analyzed and compared with theVISSIM simulation results.Finally, the Taizhou City of Zhejiang Province is selected to have a case studyon emergency traffic evacuation for typhoon storm surge disasters. The submergedrange and depth of the storm surge disasters are forecasted using ADCIRC, theevacuation scope and popuation are determined, then the emergency trafficevacuation under typhoon storm surge disasters is analyzed combining the numericalsolution methods and the microscopic traffic simulation methods.