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A calibrated, coupled model (COAWST) of the Bohai and Yellow Seas was employed to examine the contributions of waves and tides to the sediment transport, and to understand the dynamic factors controlling bottom sediment resuspension around the Shandong Peninsula. The numerical results, which were consistent with the in-situ observations, illustrated two events with large values of suspended sediment concentration (SSC). The two events had similar wave heights, but SSC during the second event was more than twice that of the first one. Numerical experiments indicated that the large values of SSC east of the Shandong Peninsula were mainly ascribed to local resuspension, and that waves played a primary role in sediment resuspension for both high SSC events. The differences in SSC and bottom shear stress between the two events were mainly due to differences in wave period, representing about 65% of the total difference, and the non-linear interactions of wave and currents played a secondary role. Therefore, wave period is an important factor along with wave amplitude in the contribution of waves to sediment resuspension in this region. The combined actions of waves and currents dynamics dominate the sediment resuspension rather than either factor in isolation. Due to sheltering effect by the Shandong Peninsula, the wave effect on sediment resuspension was less to the south of the Peninsula than that to the north and east. In addition, the Shandong Coastal Current was enhanced by the northerly wind leading to more sediment transport southward along the coast of Shandong Peninsula, but this has small effect on the difference of suspended sediment concentration between two storm events. • Large values of suspended sediment concentration east of the Shandong Peninsula is mainly due to local resuspension. • The combined actions of waves and tidal dynamics dominate the sediment resuspension. • Wave period is an important factor along with wave amplitude in the contribution of waves to sediment resuspension. [ABSTRACT FROM AUTHOR]

The long-distance transport of Yellow River sediments has formed an omega-shaped ('Ω') distal muddy deposit in the Yellow Sea. Numerous studies have investigated the sediment dynamics and sedimentary evolution of the deposit, but several key questions remain unanswered due to insufficient observations. To reveal the mechanisms of sediment dynamics and quantify sediment transport and deposition processes, this study collected field datasets in the depocenter of the muddy deposit off the Shandong Peninsula. Bottom mounted tripods were deployed from August 18 to 27, 2017, and from February 23 to March 2, 2018, during which two strong wind events with speeds of over 10.8 m/s occurred. The results showed that near-bed suspended sediment concentration responded directly to varying hydrodynamic conditions, and significant differences in suspended sediment concentration between two wind events could be ascribed to a number of factors (e.g., tidal current, wave periods, wind stress, turbulence). The harmonic analysis demonstrated that suspended sediment variations during the spring tide were directed mainly by resuspension, while resuspension and advection contributed equally at neap tide. The variations in background suspended sediment concentration can be ascribed to the residual current. Furthermore, the sediment transport pattern is similar to the pattern of water circulation. Generally, the along-shore suspended sediment flux is about one order of magnitude higher than the cross-shore flux. In summer, the suspended sediment was transported mainly downcoast. In winter, sediment was transported downcoast during wavy periods and upcoast during calm periods. Advection dominated sediment flux in most cases, except during wavy periods when local resuspension increased significantly, and the contribution of resuspension term to along-shore flux was up to 87%. Meanwhile, cross-shore flux also increased significantly under strong winds, which was simultaneously modulated by downcoast and offshore winds. After statistical analysis, we found that offshore winds controlled the cross-shore sediment transport in winter. Using parameterized calculation and statistical analysis, the average accumulation rate of the study site was estimated to be 0.6 cm/yr. During calm periods, lower background sediment concentration in summer led to lower deposition rates than in winter. In addition, the frequent strong wind events in winter cause extremely high erosion rates. This study provides new perspectives on quantitative variations in suspended sediment transport and regional erosion/deposition from synoptic to seasonal variations in the distal mud deposit. • In-situ observations at the bottom boundary layer were conducted in summer and winter on the muddy deposit off the Shandong Peninsula. • The advection dominates sediment flux in most cases, except for during wind gusts when local resuspension increases significantly. • Combining parameterized method and observational data, the accumulation rate is estimated. [ABSTRACT FROM AUTHOR]