Research On Numerical Forecast Modeling Of Storm Surge And Floodplain And Its Application

Storm surge is one of the most serious disasters in all the world's marine disasters, which threats to human life and property safety. China has a long coastline and vast waters which provide objective favorable conditions for economic development, but because of the tropical cyclone in annual summer and fall, the cold wave and winds in winter and spring, China becomes a frequent hazard of the area caused by Storm surge. Studying on the physical mechanism of the rise and development of storm surge, and on the course of the coastline invasion is of great theoretical significance, especially research on the storm surge forecasting method is of an urgent practical significance.Based in Tianjin coastlines, coastal features and the numerical model of two-dimensional extratropical storm surge, taking into account the impact of the wind and waves for storm surge, the paper deduced the two-dimensional control equation of storm surge and floodplain. Then, the author makes use of ADI format of finite difference method to disperse and solve the storm surge equations, at the same time adopted the unstructured grid method of finite volume theory to disperse and solve the control equations of floodplain. Hereby the paper established the numerical model of storm surge and floodplain, which can calculates the tide process and floodplain areas, achieves the purpose of the real-time forecasting for storm surge.To improve the border precision of mathematical model of storm surge floodplain ,the dissertation brings forward the method of a harmonic analysis, nested model and wind field model together to make sure the boundaries of mathematical model of storm surge and floodplain, seeing about the impact of the wave radiant stress on water rising of storm surge and floodplain process. Through the simulations for the two course of storm surge which happened in March .2007 and August .2007 in Bohai Bay, which present storm surge instance process by the coast of the Bohai Bay and floodplain process under the suppose of the assumed height of the seawall .Then the calculated tide compared with Tanggu actual tidal data, the results show that mathematical model of storm surge and floodplain has a forecasting functions. This dissertation is of practical value for storm surge forecasting of Tianjin Binhai New Area.