ABSTRACT
The west shoal of Lingdingyang bay is a vital sediment channel and trap, which is also a natural barrier to protect the Lingdingyang deepwater channel. According to the measured data and hydrodynamic simulation results, the dynamic characteristics, sediment transport, and deposition characteristics were discussed to explore the transport mechanism of suspended matter in the study area in the dry season, which can provide an essential theoretical basis for waterway regulation and engineering construction in this area. The results show that: 1. In the dry season, West shoal is a flood-dominated region, and vertical circulation is more evident on the south side of point 4# and the Lingding waterway on the eastern side of West shoal, where the residual current of the bottom and the middle layer is from sea to land, and the surface is from land to sea. 2. Flood and ebb channels strengthen the asymmetry of ebb and flood current, thus affecting the suspended sediment transport and deposition. 3. West shoal has a dynamic environment with bidirectional trapping sediment. In the ebb period, river flow diffuses in the beach surface and is filtered by the estuarine front. The two processes quicken sediment deposition. In the flood period, the sediment is transported from sea to land, and the fresh and saltwater mixing environment is conducive to suspended sediment deposition. 4. According to the suspended sediment transport mechanism, horizontal flow sediment transport is primary, followed by tidal trapping and vertical circulation transport. 5. Human activity has a more significant impact on suspended sediment transport. After 2000, large-scale port construction, channel dredging, and other water engineering increased the suspended sediment concentration transported by the tidal current to the West shoal and deposited. Silt strength in 2000 was 2.65 times than before.
