Spatial and temporal variability and transport characteristics of suspended sediments in the Miaodao Channel at the tidal cycle scale

Based on MODIS remote sensing images and MIKE21 numerical simulation, we investigated the distribution and dynamics of suspended sediment under tidal currents at different wind speeds in Miaodao Strait, Bohai Sea, North China, and examined the characteristics of suspended sediment transport and the main controlling factors across different seasonal tidal cycles. Results indicate that the suspended sediments were predominantly transported from the Bohai Sea to the Yellow Sea through the Miaodao Strait via tidal residual currents in both winter and summer, and the transport flux significantly was enhanced in winter. The influence of winter wind on the suspended sediments in the study area was pronounced. When the wind speed increased from 3 to 7 m/s, the concentration of suspended sediment was approximately doubled. When the wind speed increases to 11 m/s, the concentration of suspended sediment increased by 4～10 times. In contrast, the suspended sediment concentration observed under the same wind speed (11 m/s) during summer was markedly lower than during winter. During summer, wind-driven currents had relatively minor impact on sediment resuspension and transport, showing mainly tidal residual currents. Conversely, in winter, wind-driven currents played a dominant role in the suspended sediment transport in the study area.