北部湾三维潮汐潮流数值模拟

Numerical Simulation of 3-D Tide and Tidal Current in the Beibu Gulf

潮汐潮流变化对海洋建设、民生、国防等方面都有重大意义,深入了解北部湾潮汐潮流变化可为北部湾沿海港口航道建设等提供重要的参考依据。本文基于有限体积海岸海洋模型(Finite-volume coastal ocean model,FVCOM)建立了一个三维潮汐潮流数值模型,对北部湾的潮汐潮流进行数值模拟分析,同时收集了历史潮位站、2个实测潮位站以及4个海流实测站点数据对模型结果进行对比验证。结果表明,北部湾湾内以规则全日潮为主,湾内同时存在规则全日潮流、不规则全日潮流以及不规则半日潮流,潮流运动形式主要以往复式潮流为主。在涨落急流场中,最大流速点位于琼州海峡口处,流速达到157 cm/s,计算得到的最大可能流速也位于琼州海峡内。北部湾内余流平均流速为2 cm/s,余流通过琼州海峡从外海进入北部湾,并沿着广西近岸流动,在湾内形成一个气旋式环流。通过与实测资料对比,本研究所进行的数值模拟结果与实测资料基本吻合,能够反应出近年来北部湾水动力状况,为北部湾海洋工程建设以及环境保护提供了重要的科学依据。

It is of great significance to ocean construction,people's livelihood,national defense and other aspects to understand the change of tidal current in Beibu Gulf,which can provide important reference for the construction of coastal ports and waterways in Beibu Gulf.Based on the FVCOM numerical model,a 3-D tide and tidal current numerical model was established to simulate and analyze tide and tidal current in Beibu Gulf.Data of historical tidal level stations,two observed tidal level stations and four observed tidal current stations were collected to compare and verify the model results.The results showed that the regular diurnal tidal current,irregular diurnal tidal current and irregular semidiurnal tidal current exist simultaneously in the Beibu Bay,and the former double tidal current is the main one.In the fluctuation flow field,the maximum velocity point was located at the mouth of the Qiongzhou Strait with the velocity reached 157cm/s.The calculated maximum possible velocity was also located in the Qiongzhou Strait.The average velocity of the residual current in the Beibu Gulf is 2cm/s.The residual current flowed into the Beibu Gulf from the open sea through the Qiongzhou Strait and flowed along the shore of Guangxi,forming a cyclonic circulation in the bay.Comparing with the measured data,the numerical simulation results in this study were basically consistent with the observed data,that can reflect the hydrodynamic status of the Beibu Gulf in recent years,and provide an important scientific basis for the Beibu Gulf ocean engineering construction and environmental protection.