Annual Variation of Suspended Sediment Concentrationin Bohai Bay Based on ADCP

Based on the measured intensity of echosignal of ADCP, and combined with the short-term synchronous measurement of suspended sediment concentration(SSC), the SSC of long time series is inverted, and the variation characteristics and influencing factors of SSC in Bohai Bay in the past year were quantitatively analyzed. The results show that the SSC in this area has obvious seasonal variation under the influence of wind and wave, and the concentration is relatively high in seasons with strong wind and waves. The net transport of suspended solids per unit width also has obvious seasonal variation. Under the action of seasonal strong wind waves, the net transportation of suspended solids increases obviously. In different seasons, however, the net transport direction of suspended solids per month has different main transport direction.The net transport of SSC also has obvious seasonal variation. Under the action of seasonal strong wind waves, the net transport of suspended solids increases significantly; and in different seasons, the net monthly transport direction is different.The diurnal variation of SSC is obviously controlled by tidal current, while the long-term variation of SSC is mainly related to the variation of wind field.Both the process of rapid tidal current and the wind-induced waves can cause sediment resuspension, resulting in a significant increase in SSC.