九龙江口-厦门湾三维潮流数值模拟

The Three-dimensional Tidal Current Numerical Model in Jiulongjiang Estuary and Xiamen Bay

采用浅水半隐式三维数值模型,考虑九龙江径流影响,运用垂向水平分层法,计算了包括九龙江河口、厦门西港、东海域、同安湾,以及大小金门的厦门湾全海域各固定垂直分层的水平和垂直流速分量.由于在浅滩处采用了干湿动边界处理方法,较好地重现了涨落潮造成的潮间带间歇性出没,提高了模型的计算精度和适用范围,计算结果与实测资料吻合良好.通过讨论各层的潮流场分布特征,显示厦门湾海域潮流以正规的半日潮为主,大部分海区潮流运动形式都为往复流,其中围头湾、大小金门水道、厦门东侧水道以及青屿水道为强流区.

Based on semi-implicit finite difference methods for three-dimensional shallow water flow, considering the effect of the runoff of Jiulongjiang, using the fixed depth method in vertical direction,a three-dimensional tidal current numerical model is established for Jiulongjiang estuary and Xiamen bay. The computational domain include Jiulongjiang estuary, Western Xiamen Harbor, Eastern sea area of Xiamen, Tong＇an Bay, Dajinmen island and Xiaojinmen island. The model we established simulates the velocity of every fixed depth layer in horizontal and vertical. This paper summarizes the development of the moving boundary techniques, analyses the advantages and disadvantages of some present methods and then selects a suitable drying-wetting moving boundary technique. Compared with other drying-wetting moving boundary techniques, this method can ensure the water quantity balance and the precision of calculation. The model using this drying-wetting moving boundary can successfully simulate the tidal current of Xiamen Bay and reproduce the intermittent appearance of intertidal zone. The results indicate that the computed values match the observed ones quite well and reflect the true hydrodynamic characteristics. The results of tidal current of each layer, displays that the tides are regular semidiurnal, and the tidal current is rectilinear in most areas. There are stronger current areas in Weitou Bay, Dajinmen channel, Xiaojinmen channel,east of Xiamen channel and Qingyu channel.