Numerical Simulation Of Wind Waves,Storm Surges And Inundation During Typhoon Processes

China is one of the countries that suffer typhoon disasters most in the world.Every year,the giant waves and storm surge caused by typhoon have generated huge losses of human being and property in the coastal areas of our country.Hence,accurate numerical simulations of typhoon,storm surge and flooding are of significance for design of coastal defence structures and evacuation routes as well as land use planning.In this paper,a mesoscale atmospheric model WRF was used to simulate the wind field,and a wave-current coupling model SWAN+ADCIRC was used to simulate the processes of wave,storm surge and flooding.Different situations were simulated to study the influence of global climate change and sea level rise on typhoon,wave,storm surge and inundation.This may help local government for a better decision in disaster prevention and reduction of storm surge.In this paper,the 201409 typhoon “Rammasun” was simulated by using WRF model.The impact of different physical processes and parameters on track and intensity of typhoon was analysized.The average deviation of track,lowest pressure and maximum wind speed near center are 27.3KM,6hpa,4.69m/s respectively.Ferrier microphysics sheme and K-F cumulus parameterization are suggested in the simulation of typhoon “Rammasun”.SST and nudging are also recommended.The wave-current coupling model SWAN+ADCIRC was used to simulate the wave and storm surge during the typhoon,the validity of model was verified by comparing the simulation results with measured data.Based on the simulation results,the change processes of wave and storm surge in the South China Sea especially in the coast areas of Hainan Island were studied,from which it is found that the wind speed and wave hight as well as storm surge in the right of the eye of wind are stronger than these in the left.Meanwhile,the ASTER GDEM terrain data and the land useage data were used to simulate the flooding process caused by typhoon “Rammasun”.Fujita-Takahashi typhoon model and the wave-current coupled model were used to study the effects of different strength of typhoon on storm surge by considering the global warming effect.It is found that the impact of the sea level rise on wave climates is relatively small,but obvious on inundation area.