废黄河口海域的悬沙输运机制研究

The abandoned Huanghe (Yellow) River delta is an important source of sediment on the inner shelf of the South Yellow Sea. To understand the mechanisms of sediment transport in the coastal ocean of the abandoned Huanghe River subaqueous delta, the tidal asymmetry parameters, residual flows, and suspended sediment transport flux were calculated based on in-situ data obtained in the 10 stations located from nearshore to offshore in summer and winter of 2015~2016. Results show that the suspended sediment transport patterns varied significantly in space. Suspended sediment in most sea areas is transported southward along the isobaths, and only a part of them is transported shoreward or northward on the nearshore side, and in the farthest offshore station is transported northward but the transportation rate is small. The suspended sediment transport in the nearshore shallow water is dominated by advection while that of other offshore areas is dominated by resuspension. The direction of net suspended sediment transport diverges from the direction of residual flow (net water transport) due to that flow velocity and suspended sediment concentration are sometimes out of phase. The relationship between sediment settling velocity and the asymmetry of suspended sediment transport flux shows that the larger the settling velocity, the higher asymmetry degree of suspended sediment transport. The small settling velocity is responsible for the temporal inconsistence between near-bottom velocities and suspended sediment concentrations, resulting in vertical differences in net suspended sediment transport rates in the abandoned Huanghe River delta.