黄茅海河口潮波的传播特征与机理研究

黄茅海位处珠三角的西南,潮波自外海向陆的传播过程中,潮差和潮波性质都发生复杂的变化,对其传播过程及背后机理的研究具有重要的理论和实际意义。采用环境流体动力学(Environmental Fluid Dynamics Code, EFDC)模型,通过不同时段的观测资料对模型进行良好验证后,分析了枯季和洪季时潮波在河口内传播过程中的潮差变化、水位与流速的相位关系的变化情况,探讨了合山水闸的存在以及黄茅海与珠三角河网的相互作用对河口潮波的影响, 结果表明地形变化、摩擦力作用、入射波与反射波的叠加是造成潮波沿程变化的主要原因,合山水闸形成的反射波影响范围可达上百千米,而黄茅海与珠三角河网的相互作用减小了河口的潮差。珠三角的磨刀门河口与伶仃洋—虎门—广州河口的潮波传播表现出与黄茅海河口的不同特征。

The study of tidal propagation the in Huangmaohai Estuary and its underlying mechanisms

The Huangmaohai Estuary is located in the southwest of the Zhujiang(Pearl 1) River Delta (ZRD). Tidal propagation in the estuary endures complex variations from the offshore into the inland. Understanding its transformation processes and the underlying mechanisms is of great importance in both theoretical and practical perspectives. The Environmental Fluid Dynamics Code(EFDC) model was utilized and well calibrated by various sources of observation data. After then, the variations of tidal amplitudes and the phase differences between water level and current along its propagation were studied. The impacts of an upstream lock—Heshan Lock and the interaction between the estuary and the ZRD river-network were investigated. The model results clearly indicate that topography, bottom friction and the combination of incident and reflected waves all play important roles in the tidal propagation processes. The existence of Heshan Lock can impose an impact extending up to 100 km. The interaction between the estuary and the ZRD river-network results in a reduction of tidal amplitudes in the estuary. Comparisons among the Modaomen Estuary and the Lingding Bay-Humen-Guangzhou Estuary and the Huangmaohai Estuary demonstrate their unique characteristic.