Compounded Scenarios Simulation And Emergency Evacuation Of Storm Surge Disaster In Coastal Cities

Unexpected natural disasters occur with increasingly frequency and have caused ecological damage and human casualties worldwide. Establish a scientific system for disaster prevention and mitigation to ensure the global/regional sustainable development is our priority. Given the high population density, developed economy and frequent meteorological disasters, coastal areas have become the focus of relative research in regional disaster prevention and mitigation. What's more, regional sea-level rise and rapid progress of urbanization have brought negative impact on the evolution of hazard-formative environment, and increased the vulnerability in these areas. Therefore, under the low-level pre-disaster warning system, coastal areas are exposed to a high risk of extreme hazard events. The construction of complex scenarios including disaster risk modeling and assessment, and emergency response system will develop into the major trend in the field of disaster prevention and reduction.Under the financially supported by the National Natural Science Foundation of China(No.40730526, No.40571006), Shanghai Science and Technology Venus Project(No.09QA1401800), and PhD Program Scholarship Fund of ECNU(Project No.2010033), this dissertation integrated the urgent needs of response to extreme storm surge disaster and conducted the following work:(1) discussed the disaster risk driving force-presure-state-response (DPSR) mechanism; (2) constructed a methodology of disaster emergency shelter system includes complex disaster simulation, disaster risk mapping and early warning, and dynamic emergency evacuation simulation; (3) carried out empirical study in Shanghai. The study aims to provide theoretical and technical supports for Shanghai and other coastal cities in preparing plans for disaster prevention and emergency evacuation.Several main conclusions are shown as follows:Firstly, this paper proposed a DPSR theory model to describe the coastal storm surge disaster risk system from the perspective of urban system dynamics. That is, with typhoon storm surge as the driving force, analyzed the risk profile under the environmental evolution pressure of sea rise level, land subsidence, erosion/siltation of seabed, and so on. Discussed the response strategy from the risk zoning, early warning and emergency evacuation, and studied the connotation and interrelationship of the risk system elements in details. Hence, an urban-oriented paradigm of disaster risk was developed to complement the theoretical system of the natural disaster risk assessment and control. Secondly, based on scenario analysis and risk assessment theories, storm surge disaster risk was compound by the scenarios of time, space and intensity. The factors in storm surge disaster scenarios were analyzed by qualitative and quantitative methods. Compounded scenarios were combined with Low, medium and high scenarios matrix by deduction method. The process of a storm surge disaster in different kinds of complex scenarios were simulated with the support of hydrodynamic model MIKE 21 HD and Geographic Information System (GIS) techniques, and the output can be used to construct the disaster scenarios risk database. Besides, the disaster risk zoning and early warning were implemented by employing visualization and thematic mapping techniques.Thirdly, the space-time activity characteristics of population in a given scenario were analyzed based on the above simulated results, and the affected population and spatial distribution model was established. Open space such as school was evaluated in terms of evacuation Suitability, and alternative shelter services were analyzed by applying set covering model. Based on flood control network system, dynamic emergency evacuation process was implemented by employing the optimal path algorithm.Fourthly, based on secondary development platform SIMGIS, using development model named Visual Studio C# & ArcGIS Engine 9.3, coastal storm surge disaster risk zoning and emergency evacuation desktop system was developed. It integrated a number of tools effectively, such as disaster risk zoning, emergency evacuation; and could basically meet the functional requirements for integration and visualization in present disaster study. The results provide an effective way for the emergency evacuation plan.Finally, based on the above theoretical and approaches, the empirical study of Shanghai was carried out in its risk complex simulation and emergency refuge of regional storm surge disaster. The results show, the tide level growth rate of main tide gauge stations in Shanghai is 2-3mm/a, the average rate of land subsidence is 2mm/a during 2010-2030. the evolution of hazard-formative environment will be accelerated, and the present sea embankments are exposed to the risk of typhoon storm surge once Millennium.There are 4 sections with high risk in Pudong and Jinshan that are in urgent need of the construction of emergency system and defend projects.Millennium extreme disaster along dike break event in the future, which will lead to an emergency transfer of affected people. Besides, the emergency shelter system should be sped up at all levels.