Development And Application Of A Numerical Model Coupling Storm Surge, Tide And Wind Wave

The coast of China is offen attacked by strong storm surges, which usually caused series disasters. To improve the technologies for prevention and mitigation of disasters induced by storm surge is thus a big challenge to the Chinese coastal engineers. This paper developed a coupled numerical model considering the interactions between storm surge, astronomic tide and wind wave. By using this model, the dynamic characteristics of storm surge, tide and wave are studied, and the interaction effects among those hydrodynamic factors are discussed. The model is applied to Hangzhou Bay, which is a typical strong tide river mouth and usually suffers from the typhoon.The newly developed model includes a wind field module, a water level prediction module and a wave module. The three modules are coupled, considering the interaction of typhoon, wave and astronomic tide. Comparing the computed result and the measured data during the storm surge caused by typical real typhoons in Hangzhou Bay, it shows that the developed model works well on simulating the storm surge and typhoon wave.The effect of each hydrodynamic factor on strom surge is analysed. As typhoon is the primary cause of strom surge, the effects of the typhoon characters on storm surge are studied. This paper simulated the storm surge induced by a typhoon moving along the route perpendicular to the shoreline. The paper compared the effects of wind stress and low air press on the storm surge. The nonlinear interaction between astronomic tide and storm surge also plays an important role in storm surge simulation. The paper computed the water levels of storm surge in ideal and real landform of Hangzhou Bay separately, analysed the influence of nonlinear interaction between astronomic tide and strom surge on storm surge. Moreover, the wind wave caused by typhoon is also a disaster important factor in disaster prediction, and wave radiation stress would affect water level. The paper simulated the typhoon wave process in Hangzhou Bay with typical typhoons. The wave distribution is discussed. Meanwhile, the interaction between typhoon wave and storm surge is analysed.Based on the research above, the paper designed a most dangerous typhoon in Hangzhou Bay. By simulating the storm surge under the designed condition, the paper pointed out the most dangerous area in the Hangzhou Bay. It is valueble for prevention and mitigation of the disasters induced by strom surge in the coastland around the Hangzhou Bay.