Identify the impacts of waves and tides to coastal suspended sediment concentration based on high-frequency acoustic observations

Abstract

Abstract High-frequency measurements of wind, waves, tides, suspended sediment concentration (SSC), and turbulence were made using an autonomous meteorological station and optical and acoustic instruments over 34\u202fdays during January 20–February 23, 2016, in Heini Bay, Yellow Sea. The responses of SSC on different dynamic processes are analyzed by decomposing the velocity and SSC fluctuations into wave and turbulent components. In the presence of SSC fronts, the horizontal advection by the reciprocating tidal flow would cause an asymmetry of SSC in a flood-ebb tidal cycle. The presence of swells induced intensified sediment resuspension and a flood-ebb symmetry of SSC. In the bottom boundary layer, the net horizontal sediment fluxes were significantly increased in the presence of strong waves. Significant amount of suspended sediments were taken away from the study area, implying the occurrence of coastal erosion.