大亚湾和大鹏湾两个相邻海湾潮波浅水变形的异同分析

Similarities and differences of shallow water deformation of tidal wave in two adjacent bays:Daya Bay and Dapeng Bay

利用实测资料分析重构了大亚湾和大鹏湾潮汐水位"双峰"现象,确定了浅水分潮的异常增长是潮位"双峰"现象的主要成因,其中四分之一日分潮和六分之一日分潮起着至关重要的作用。通过SCHISM模型构建大亚湾和大鹏湾附近海域高分辨率水动力模型,模拟结果表明近岸海域,在大亚湾以东,潮汐类型为不规则全日潮,以西为不规则半日潮,在两个海湾内均为不规则半日潮;研究海域的潮流均表现为不规则半日潮流。四分之一日分潮和六分之一日分潮在大亚湾和大鹏湾的不同变形过程是造成两个相邻海湾水文差异的直接原因。通过构建不同底摩擦强度、消除水底地形以及改变海湾水深的数值实验研究表明,分潮传播方向与水深变浅方向是否一致,是导致两个海湾潮波浅水变形不同的根本原因。

The phenomenon of "double peak" of tidal water level in Daya Bay and Dapeng Bay was reproduced by means of the measured data, and it is determined that the abnormal growth of shallow water tide is the main cause of the phenomenon, among which the one-quarter-day tide and the one-sixth-day tide played a crucial role. The high-resolution hydrodynamic model of Daya Bay and Dapeng Bay was constructed by using the SCHISM model. The simulation shows that in the open sea outside Daya Bay and Dapeng Bay, tidal type is irregular diurnal tide in the eastern sea, tidal type is irregular semidiurnal tide in the western sea and two bays. The pattern of current is irregular semidiurnal currents in study area. The difference of hydrology between the two adjacent bays is directly caused by the deformation process of one-quarter-day and one-sixth-day tide in Daya Bay and Dapeng Bay. Through the numerical experiments of building different bottom friction intensity, eliminating bottom topography and changing water depth, it is shown that whether the direction of split tide propagation is consistent with the direction of shallower water depth is the fundamental reason that leads to the different tidal wave deformation in two bays.