基于模型耦合的北部湾风暴潮增水与风浪模拟研究

Study on the Coupled Numerical Simulation of Storm Surge and Wind Wave in Beibu Gulf

关键词:  风暴潮增水  数值模拟  模型耦合  北部湾

Key words:  storm surge  numerical modelling  model coupling  Beibu Gulf

摘要:

台风风暴潮引发的增水和风浪效应是造成沿海低地灾害和损失的重要因素。本文设计了区域嵌套、波-流耦合的有限元数值模拟系统，对北部湾及附近海域风浪和增水过程进行有效模拟，精度达到应用要求。结果表明北部湾在台风影响下引起明显风浪和增水效应。台风中心风浪较小，仅1 m以内；而台风臂扫过海域风浪较大，可达9 m以上。最大增水海域出现在北部湾东侧靠近琼州海峡附近，可达2.5 m。风浪与增水叠加具有非线性效应，最大增水与最大风浪出现时间如与大潮高潮位相遇易形成超高水位，将对北部湾沿岸低地造成巨大淹没风险。本研究意在突破北部湾现有模型局限性，为进一步深化科学研究和工程应用提供基础数据。

Abstract:

Storm surges and wind waves induced by typhoon are the two important factors causing flooding disaster and economic loss in the coastal lowlands. In this paper, a regional nesting and wave-current coupling finite element numerical modeling system was designed to effectively simulate the storm surges and wind waves in Beibu Gulf and surrounding water, and the accuracy meets requirements of the application. The results show that wind waves and storm surges has been significantly increased under the influence of typhoon in Beibu Gulf. The wind wave in the center of typhoon is small, only within 1 m, while the wind wave of the typhoon arm sweeping over the sea is larger, up to 9 m. The largest storm surge area appears on the eastern side of Beibu Gulf near Qiongzhou Strait, which can reach 2.5 m. The superposition of wind wave and storm surge has a nonlinear effect. If the maximum increase of storm surge coincides with the peak wind waves, a super high water level will appear when they meet with the high tide level, which will cause a great risk of flooding to the lowlands along Beibu Gulf. The purpose of this paper is to break through the limitations of existing models in Beibu Gulf and provide basic data for further deepening scientific research and engineering applications.