Distribution pattern of surface sediments around the abandoned Yellow River estuary of North Jiangsu Province and its controlling factors

The distribution pattern of sediments and its controlling factors are studied based on grain size analysis results of surface sediments collected from the coastal waters surrounding the abandoned Yellow River Estuary of Jiangsu Province. Results show that there are four kinds of sediments i.e. silty sand, sandy silt, silt and mud in the study area, dominated by silt, which is 66.3% in content and covers 50% of the area. Dominant particles are very concentrated, and the Φ value of main peak decreases with the increase in grain size from mud to silt, sandy silt and silty sand, and the tail of the low frequency are always longer on the side of fine particles. In terms of sedimentary environment, the study area is divided to high energy and low energy regions, and the low energy region could be further subdivided to shallow water and deep water areas. The distribution pattern of sediments of the study area is mainly controlled by wave and tidal currents. Off the south shore of the harbor where the sediment is coarser, wave action dominates and the hydrodynamic condition is the strongest. The area covered by sandy silt, however, is mainly controlled by both the actions of wave and tidal currents, and the area covered by silt is under the control of tidal current.