Research On The Couple Numerical Forecasted Model Of Storm Surge And Waves

Storm surge is an important topic on the development of modern Marine technology, because it threats human life and property safety in the coastal cities. China has a long coastline, which is affected by the tropical cyclone in annual summer and fall, the cold weather and winds in winter and spring. Storm surges frequently land on these coastal cities. Studying on the physical mechanism of the generation and development of storm surge, and the course of the coastline invasion is of great theoretical significance, especially researches on the accurate forecasted model is of an urgent practical significance.The study analyze the generating mechanism and coupling effect of storm surge and waves, a coupled numerical model of storm surge and wave is developed. First, the paper deduces the two-dimensional control equation of storm surge, then makes use of ADI (Alternating Direction Implicit Method) format of finite difference method to disperse and solve the storm surge equations. Based on the work a numerical simulating model of storm surge is builed, the purpose aims at forecasting the storm surge in the simulated area. To calculate wave characteristics, SWAN model described by the action balance equations is adopted. The more accurate results are achieved by the coupled model through currents and wave radiation stresses.To improve the border precision of this numerical model, local deepening and water range reducing are adopted to deal with the boundary of shallow water, the method of harmonic analysis, nested model and wind field model come together to make sure the water boundary. The numerical model of storm surge, SWAN model and the coupled model are applied to two typical storm surge process in Bohai Bay, we gain the water level and current field with effect of wave radiation stress, the distribution of significant wave height and radiation stress effected by current otherwise. The results show that the velocity of current increases because of radiation stress, especially in the area of land boundary where strongly affected by radiation stress. When wave field affected by current is caculated, the significant wave height is different from the results which ignore effects of current. But there is no obvious influence for radiation stress. From the upper ananlysis, it is believed that the study on the coupled model is of a great value for storm surge forecasting.