西沙门悬沙输移机制分析和讨论

摘要

Based on the dynamics measurement of water levels, current velocities and suspended sediment con⁃centrations in Xishamen, the transport flux of suspended sediment was calculated by the flux decomposition meth⁃od, and the space⁃time distributional characteristics were analyzed. The results show that the advection plays a sig⁃nificant role in the regions and the second factor is the tidal pumping effect. The dynamic mechanism of main items was discussed in term of tiding, velocity and suspended sediment concentration process. The conclusion shows the Euler residual current effect is determined by tidal power. The Stokes current is influenced by the nonlinear effect of tide and wave. The tidal pumping effect is induced by the bottom sediment suspended, tidal dissymmetry and con⁃centration diffecence.%以西沙门水沙实测资料为依据，运用悬沙通量机制分解法将悬沙净输移通量表示为多个动力影响项，讨论区域内悬沙输移的时空特征，分析认为平流输沙在研究区域内为主要输沙项，“潮泵效应”输沙项为次要项。从涨落潮、流速和含沙量的变化过程讨论其动力机制，结果表明：西沙门悬沙浓度在潮流作用下具有明显的潮周期变化，悬沙沿岸输移；平流输沙中欧拉输沙项主要取决于潮动力大小，斯托克斯输沙项受潮波非线性效应影响；“潮泵效应”输沙与泥沙悬浮“滞后效应”、涨落潮流流速的非对称性和当地悬沙浓度相关。