Temporal and spatial dynamics of suspended sediment and its driving mechanism in the Yellow River Estuary

Affected by fluvial sediment discharge, wind waves and tides, etc., suspended sediment in estuaries and adjacent waters has significant temporal and spatial changes. Based on the GOCI remote sensing images at hourly resolution, this paper uses the optimal remote sensing inversion algorithm, combined with spatial analysis and statistical methods to deeply study the temporal and spatial dynamic characteristics and driving mechanism of suspended sediment in the Yellow River Estuary and adjacent waters. The results show that the impact of fluvial sediment discharge on the concentration of suspended sediment is concentrated in the nearshore area of the estuary. The impact of high fluvial sediment discharge on the distribution of suspended sediment concentration can reach about 20 km offshore and spread to the Gudong nearshore area. Strong winds can cause intensive resuspension of sediment near the old river mouth of Qingshuigou, forming a high-concentration suspended sediment area. The flood and ebb tides have a significant impact on the hourly-scale suspended sediment concentration, and affect the dispersal of suspended sediment from north to south. The variation and dispersal range of the suspended sediment concentration in the spring tide are larger than that of the neap tide due to different tidal flow velocities. There is an obvious negative correlation between water depth and suspended sediment concentration. According to the difference of driving factors, the suspended sediment concentration present exponential, power function, and linear relationships with the increase of water depth.