Zhejiang Coastal Storm Surge Of The Wave Impact Study

The marine environment problem caused by ocean disarsters is increasingly attention by the people in coastal. Coastal area of Zhejiang Province, which is located in the southern wing of Yangtze, is a very important region for its prosperous economy and numerous population. The main natural disasters are typhoon and tide,waves,rains caused by typhoon since ancient time. Typhoon waves caused by storm tide will have a destructive effect on the project of the coastal area, for instance, fishing boats were sank, deficit of sea-farming industry. Since1990s, the effect of typhoon on Zhejiang Province has been increased. Therefore, it is very significant to study how Typhoon waves are i mpacted by storm tide.The research analyzes the datas of many years observation from various wave stations in the coast of Zhejiang Province. Smaller near the coast, Gradually decreasing from Dachen, Nanji, Shengshan along the contour line to the inward, the characters of typhoon waves vary from season to season are the three disciplines of storm waves, while five typhoons in the analysis of storm surge, based on the sum of the storm surge of four basic types.After comparing of different wave calculation models, the essay determined to use energy balance equation’s SWAN model as a computational model, to choose MIKE21model as a storm tide computational model, to choose inputting storm tide into SWAN model as a calculation condition. High accuracy of simulation has been proved this model can calculate the waves i n the coast of Zhejiang Provi nee.The result of model shows that the simulation accuracy is higher under the condition of inputting storm tide and the process of wave is much closer to the real one. This result is based on the comparison of typhoon waves’calculation results when taken storm tide and average sea level into consideration. This situation is obvious in the stations which are near the coast. The comparison of typhoon waves of Zhapu’s station under the biggest warm cyclone indicates that the water depth has a big effect on the typhoon waves in extreme cases. The movement of typhoon waves related to the locations of typhoon-center. In general, the coastal waters of typhoon waves will increase when the typhoon-center get closer. Meanwhile, the nearer of the typhoon-center is, the greater the waves are, but there is a difference between the relative positions.