台风移动方向和速度对湛江市沿海风暴潮影响的数值分析

Numerical analysis of the impacts of the moving direction and speed of typhoon on Zhan Jiang coastal storm surge

基于FVCOM海洋数值模式,模拟了1409号超强台风"威马逊"和1415号台风"海鸥"的风暴潮过程,并通过数值试验,定量的研究了台风移动方向和移动速度对湛江市沿海风暴潮的影响,分析了1409号和1415号台风产生的风暴潮相差较大的原因。结果表明:台风以180°角(正西向)移动并登陆湛江时,所产生的风暴潮最大,其次是157.5°,当台风以180°角登陆时,湛江海域的最大风暴潮较台风以135°登陆时大60—90 cm;台风移动速度越快,对湛江海域造成的风暴潮越大,两者呈对数关系,台风以20 km/h和30 km/h的移速并以180°角登陆湛江时,后者对湛江海域3个站点造成的最大风暴潮较前者大将近100 cm。"海鸥"以接近157.5°的角度和30 km/h的速度登陆湛江,是导致其增水远大于"威马逊"的其中两个重要因素。

Based on FVCOM ocean numerical model, the storm surge of No. 1409 super typhoon＂Rammasun＂and No.1415 typhoon＂Kalmaegi＂was simulated, and through numerical experiments, the impacts of the moving direction and speed of typhoon on Zhan Jiang coastal storm surge was studied and the cause of the large different storm surge of＂Rammasun＂and＂Kalmaegi＂was analyzed. The results showed, when the typhoon moved and landed on Zhan Jiang at 180°angle, the storm surge is the largest, and the second is at 157.5°angle. In Zhan Jiang sea areas, the maximum storm surge caused by 180° angle landed typhoon will be greater by 60-90 cm than that caused by 135° angle landed typhoon. The typhoon move faster, the storm surge in Zhan Jiang sea area will be larger. There is a logarithmic relation between the typhoon speed and the maximum storm surge. When the typhoon landed on Zhan Jiang at 180° angle with moving speed of 20km/h and 30km/h, the latter will cause larger storm surge in Zhan Jiang coastal sea are by nearly 100 cm.＂Kalmaegi＂landed on Zhan Jiang with nearly157.5° angle and 30km/h moving speed are two important reasons of all that cause larger storm surge in Zhan Jiang coastal sea area than＂Rammasun＂.