Risk Assessment Of Storm Surge And It's Application

Storm surge is due to severe atmospheric disturbances, leading to abnormal movements of sea, so that the tidal waters affected significantly more than the normal tide level of the natural phenomenon. Based on characteristics of weather systems, storm surges are usually divided into a typhoon (hurricane) storm surges and extratropical storm surge. Storm surge disasters in China is very serious, and China got the highest number of storm surge, the loss of the worst among the Northwest Pacific National disasters. Since the founding of new China, almost every year occurred storm surge disaster.Storm surge disaster risk assessment methods are mainly researched in European and American countries, and it has been applied to empirical research in different cities to provide the scientific basis of disaster prevention plan, and achieved good results. In China, the storm surge disaster risk assessment is a new field of study. The quantitative assessment of storm surge disaster risk is not only a management basis and premise, and is the storm surge pre-zoning and pre-disaster damage assessment of the theoretical basis. By storm surge disaster risk assessment studies of Estuaries and coastal areas, to calculate and analyze possible future storm surge frequency, intensity, to analyze the possibility of seawall or dike overtopping or damage, to assess quantitatively of the damage caused by the storm surge disaster, to identify the extent of storm surge risk of different regions within the protected area, to make people aware of the likelihood, the scope and consequences of storm surges, and it will help governments, businesses and individuals to better prepare for disasters. The study is also the basis and premise for carrying out storm surge disaster risk management in future, and is the important scientific basis for decision making in guiding City future land use planning and disaster mitigation moisture.In this paper, mathematical model is provided to calculate the possible range and depth of submergence of different frequency storm surge in the condition of dike overflow or partial damage, and then counting various types of property value at submergence range of different levels, concluding the urban and rural households property, business fixed and mobile assets, agricultural assets, infrastructure and so on. The loss of various types of property value equal to various types of property value multiplied by the corresponding loss rate. These are the direct economic losses caused by storm surge and the indirect economic losses were estimated by the empirical coefficient method. Proposing a simple and reasonable evaluation of storm surge disaster risk index to assess the size of the regional risk, and the evaluation indicators include hydraulic calculation index, property index and disaster indicators. These indicators can be used to carry out storm surge risk analysis and to initially classify the risk level. And the Qiantang River estuary as a typical, the paper carried out calculation of storm surge disaster risk loss and risk evaluation according to the method mentioned. Finally, it introduces a number of storm surge disaster reduction in non-engineering measures. And it proposes to build and improve the system of protection against storm surges, based on the engineering measures (including infrastructure) which are standard and moderation, to strengthen and improve non-engineering measures in the way of legal, administrative, economic, technological and other means, to effectively mobilize and integrate the society resources, supplemented by risk-sharing and risk compensation. To protect the safety of the premise, seeking to the maximum benefit of disaster prevention and mitigation.