带丁坝型半封闭矩形海湾中M_2分潮潮波和潮流特性分析

Tidal wave and tidal current characteristics of the M_2 constituent in a semi-enclosed rectangular basin with a coastal barrier

将黄渤海海域概化为矩形海湾,山东半岛概化为垂直于海岸的巨型丁坝,形成一个带丁坝型半封闭矩形海湾。利用DELFT3D-FLOW计算模块在上述海湾中进行了M2分潮数值模拟,对其无潮点和辐射状潮流场的特性进行了分析。研究发现:考虑科氏力影响和巨型丁坝反射作用,坝前形成了明显的无潮点,但在等水深条件下并未形成辐射状潮流场,而叠加上倾斜海底地形后其得以形成;无潮点和辐射状潮流场顶端位置受水深影响明显,随着平均水深的增大,无潮点将向湾口和湾中轴线方向偏移,而辐射状潮流场顶端则向湾口方向偏移。研究结果有助于加深对带丁坝型半封闭矩形海湾中驻潮波系统形成机制和动力特性的理解和认识。

A model of a semi-enclosed rectangular basin with a coastal barrier is schematized from the Bohai Sea,the Huanghai Sea and Shandong Peninsula.Using the DELFT3D-FLOW numerical model,we have conducted the an-alyses of the tidal characteristics of the M2 constituent ,the formation mechanism of the amphidromic points and the radial tidal current field in the basin.The results show that,due to the Coriolis force and the barrier reflection, there will always present an amphidromic point in front of the coastal barrier.However,the radial tidal field is ab-sent in the case of uniform water depth with an exception of the existence of mild slope in the nearshore topogra-phy.It is found that the locations of the focal point of the radial tidal current field and the amphidromic point are affected by the mean water depth.With the increase of the mean water depth,the location of the amphidromic point will shift to the entrance and the central axis of the basin,while the focal point of the radial tidal current field will move towards the entrance of the basin.The findings in the paper will facilitate the understanding of the for-mation mechanism and dynamic characteristics of stationary tidal wave in this type of the basin.