寒潮引起的江苏沿海风暴潮潮位分布规律研究

Study on Sea-level Distribution of Storm Surges Caused by Cold Wave in Coastal Areas of Jiangsu

基于MIKE21的Flow Model模块和ECMWF再分析风场,建立了江苏沿海天文潮-风暴潮耦合数值模型,计算并验证了141008号寒潮期间蛎岈山、大丰、连云港、响水测站的风暴潮潮位,验算结果表明模型精度较高,可以用于江苏沿海寒潮风暴潮的计算。选用2002年最高天文潮位与141008号寒潮组成最不利组合,研究了天文大潮时江苏沿海风暴潮潮位和增水的分布规律。结果表明:蛎岈山站在此情况下海域增水超过50 cm的时间接近7 h,最大增水约100cm。在寒潮大风影响下,分别以弶港和蛎岈山为中心,呈扇形散开的近海区域增水明显高于其他邻近海域,增水可达1.5m,甚至更高。

Based on the module Flow Model of MIKE21,and ECMWF reanalysis wind field,a numerical model coupling the astronomical tide and the storm surge in coastal areas of Jiangsu was established,and the sea levels of storm surges in Liyashan,Dafeng,Lianyungang and Xiangshui stations during the cold wave No.141008 were calculated and verified.The verification results showed that the model had a higher precision,and could be used for the calculation of storm surges caused by cold wave in coastal areas of Jiangsu.The most unfavorable combination of the highest astronomical tide level in 2002 with the cold wave No.141008 was selected to study the distribution rule of sea level and anstau of storm surges in Jiangsu coastal areas when astronomical tide occurred.The results indicated that:under such circumstances,the duration time of the anstau over 50 cm in the sea area of Liyashan station was close to 7 h,and the maximum anstau was about 100 cm.Under the influences of cold wave and gale,the anstau in the inshore sectorial areas taking Jianggang or Liyashan as centre was obviously higher than that in other neighboring sea areas,and it could reach 1.5 m or even higher.