The Storm Surge Risk Assessment Of Simulation For Ningbo Offshore

Ningbo is a port and tourism city. In April,2010, Ningbo-Zhoushan port’s volume of cargo reached53.066million tons, more than that of Shanghai port, thus being one of the World’s Five Best Ports. Recent years, as the economy grows, Ningbo has become one important area for foreign trade. Nevertheless, Ningbo is also an area where tropical cyclonic activities frequently take place, which greatly restricts its economic development and foreign trade. Every year, Ningbo suffers great losses because of tropical storms and tide disasters, and the suffering is becoming more serious year by year. So, it is greatly helpful to Ningbo’s Economic development and government policies to study the law of cyclonic activities in this area and give effective forecasts.This paper did some statistic analysis based on the relative data about268tropical cyclones and surges that influenced Ningbo during the year of1950to2012. The paper classified the data according to the height of the greatest submergence during a storm tide and got the following data result:there are110typhoons causing a submergence higher than one meter, average1.8every year (about41%of the total);36typhoons causing a submergence higher than two meters, about once every two years(about13%of the total);12typhoons causing a submergence higher than three meters, about once every five years(about4%of the total).About15typical typhoons are studied in this paper. Grounded on the characteristics of central surface pressure, movement speed and track of these typhoons, a mode of wild field is build to simulate the maximum possible increase in water. Specifically, first, statistic approaches are adopted to determine maximum central pressure and movement speed of typhoons along the east coast of Ningbo. Second, unstructured triangular mesh finite volume numerical ocean model suitable for inshore estuaries is used to analyze the process of setting up submergence of typical typhoon0407.Compared with water level data of the nearby4ground station,the average absolute error is0.075m and average relative error is less than1.30%. Taking predicted result into consideration, the experimental typhoon track can be investigated. Meanwhile we can figure out that the possible maximum water level caused by assumed typhoon along the offshore of Ningbo is773.5cm.