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洋山海域自2002年建港工程以来,先后封堵了北岛链三个过水汊道,使得海域附近水动力结构发生显著变化。采用工程前后大量水动力实测资料,并结合数值计算结果,对洋山海域工程前后的水动力特征进行了综合分析。研究结果表明:工程后大部分海域涨潮流速降低,但小洋山前沿除外;整个海域落潮流速度增加,但地形急剧缩窄的东口门区域增幅并不显著。讨论认为,地转偏向力显著增强了海域北部区域特别是小洋山前沿海域的涨潮流速,是小洋山岛屿前沿海域涨潮流速工程后维持不变的重要原因;受南岛链不规则岸线的影响,地转偏向力对落潮流影响不显著。工程后各汊道的封堵使得落潮流外泄不畅而发生壅水,使得工程后涨潮时段海域水位低于工程前,没有壅水现象发生。工程后的涨、落憩流时段均形成了较大范围、较长时段的弱流场。
Yangshan sea area since 2002 after the Hong Kong Harbor Project, has blocked the North Island chain of three waterways, making the waters near the hydrodynamic structure of a significant change. Before and after the project using a large number of hydrodynamic data, combined with numerical results, Yangshan waters around the hydrodynamic characteristics of a comprehensive analysis. The results show that the flow velocity of tidal current in most of the sea areas decreases after the project, except for the front of Xiaoyang Mountain; the velocity of tidal current over the sea area increases, but the amplitude of eastward door area with sharp terrain narrowing is not significant. It is argued that the geostrophic force significantly enhances the tidal current velocity in the northern part of the sea area, especially in the frontier area of the Xiaoyang Mountain, which is an important reason for the unchanged tidal current velocity in the frontier area of the Xiaoyangshan Island. The influence of geostrophic force on the tidal current is not significant. After the project, the sealing of each road led to the sluggishness of the falling tide flow and the occurrence of stagnant water. As a result, the water level in the sea after the project was lower than that before the project and there was no stagnant water occurred. After the project rose, falling stream period formed a larger area, a longer period of weak flow field.