黄茅海河口沿程异常潮差数值模拟研究

Numerical Simulation to Study Abnormal Tidal Ranges Along the River Course in Huangmaohai Estuary

通过一维及ECOMSED二维水动力数值模型,分别计算了黄茅海河口潮波传播中的非线性效应和径流对潮波的影响,以及潮能通量和潮能耗散。计算结果表明:1)在潮汐的高潮和低潮时,非线性效应对潮水位的影响较为明显,且越向上游影响越显著;2)当径流量加大到一定程度时,沿程潮差逐渐向上游减小,而当径流较小时,潮差则沿程增大;3)崖门射流口潮能辐聚,同时单位面积能耗率也最高,沿河道向上游,能通量与能耗率均有所下降,能耗与能通量的共同作用,导致了沿程潮差的变化;4)在一定的潮汐和流量边界条件下,具体的整体和局部河道形态决定了河口能量分布和耗散性质,从而决定了不同河口的动力场的具体特点。

1-dimensional and 2-dimensional ECOMSED models are respectively used to calculate the nonlinear effect and the runoff effect on the tidal wave propagation in the Huangmaohe Estuary.As it is shown in the results from the calculation,1) the nonlinear effect on the tidal level becomes more obvious when it is at high water or at low water and also obvious in the further upstream area.2) The tidal range is increased with the distance further away from the sea,when the runoff flow becomes greater above a critical volume.3) The tidal energy converges at Yamen where the jet is located and the energy dissipation rate per unit area of the river cross-section is greatest.And the energy flux across the river cross section and the energy dissipation rate become decreased in the further upstream area.It is the joint action of the energy flux and the energy dissipation that makes the tidal range vary along the river course.4) Under certain boundary conditions of the tidal level and the rivel flow,the tidal energy and the energy dissipation depend upon both the over-all morphology in the estuary and the river course morphology so that the concrete hydrodynamic features are determinative.