Application And Analysis Of Storm Surge's Process Under The Influence Of Waves

Storm surge is a great natural disaster from the sea, our country subjects to it every year, especially in economically developed areas, such as the pearl river delta, offshore of Zhejiang and Fujian province, and the Yangtze river delta region, it is very important to forecast the storm surge rapidly and effectively. The 2D storm surge prediction model considered the interactions of storm surge, tide and wave was set up by our study group, it is used to compute the precision and timeliness of the storm surge. The main conclusions of this study may be summarized as:1. In recent 30 years, there are 18 typhoons impacted the Yangtze River estuary and its adjacent areas seriously, compute and analyze these typhoons according to paths and land locations. Compare the calculated wind speed, water level, changes of surge and the observed data, the precision are good.2. On that basis, the influence on water levels and storm surges caused by wave are discussed in 22 stations of Yangtze River estuary and the north bank of Hangzhou Bay. It maybe found from the results that, to the whole process of typhoons, the precision of storm surges are not improved when the influence of waves are considered, but they improve in the days around typhoons'land or close times. Especially to the near shore turning typhoons, storm surges caused by wave are over 20cm, in some stations, the value is higher.3. Compute and analyze the paths, comparisons of wind speeds, water levels, storm surges, current fields, wind fields, surge fields, comparisons of the storm surges of 22 stations and so on, and these results can be a good reference to the later typhoons of the similar paths.4. In addition, the 2D storm surge prediction model is successfully applied to the Wentai adjacent area, the precision of astronomical tide in some stations are very good. Two typhoons'storm surges are computed and analyzed, The main conclusions are as follows:in station Huangdaao and Nanjishan, wind speeds grow gradually before the typhoon lands, and reach the maximum value at the time of typhoon lands, wind speed reduce gradually after the typhoon land. The maximum speed are very high in the two typhoons, over or almost reach 30m/s. The water levels and surges grow gradually with wind speeds. At the time of typhoon lands, the water levels and surges in Nanjishan and HuangdaAo are almost at the maximum value. Because the lack of observed data, the precision of the computation results are not sure, but the work can be a good foundation for the follow-up.