The Huanghe River(Yellow River)is known by its high suspended sediment concentration(SSC)in its river mouth tidal flat.However,the factors controlling the high SSC over there are not well understood.Therefore,we condu...The Huanghe River(Yellow River)is known by its high suspended sediment concentration(SSC)in its river mouth tidal flat.However,the factors controlling the high SSC over there are not well understood.Therefore,we conducted 7-d hydrodynamic observations(water depth,wave height,and current velocity)and SSC measurements on the tidal flat off the Huanghe River Mouth.The data shows that in most of time,under the calm sea condition,the SSC ranges 0.1–3.5 g/L,and sediment discharge from the river is the main source.However,when hydrodynamics are enhanced in a tidal cycle and large-scale erosion occurs on the seafloor,resuspended sediment becomes the main source,and the SSC in the water column reaches 17.3 g/L.We find the suspended sediment flux is mainly controlled by the tidal current and Stokes drift,while the wave-induced shear stress could also affect the variation of suspended sediment flux.During the observation period,when sea under calm-rippled conditions,the current-induced resuspended sediment concentration(RSC)was greater than the wave-induced RSC.In contrast,in smooth-wavelet sea conditions,the wave-induced RSC was greater than the current-induced RSC,for instance,a single wave event was found to cause 11.8 cm seabed erosion within 6 h.This study reveals different controlling factors for the high SSC near a river-influenced tidal flat,and helps us get a better understanding of a delta's depositional and erosional mechanisms.展开更多
基金Foundation item:The National Natural Science Foundation of China under contract Nos 41072215 and 41877223the Key Science and Technology Plan of Power China Huadong Engineering Corporation Limited under contract No.KY2018-ZD-01+1 种基金the Joint Fund of NSFC and Marine Science Research Centers of Shandong Province of China under contract No.U1906230the Marine Geological Survey Project of the China Geological Survey under contract No.GZH201100203.
文摘The Huanghe River(Yellow River)is known by its high suspended sediment concentration(SSC)in its river mouth tidal flat.However,the factors controlling the high SSC over there are not well understood.Therefore,we conducted 7-d hydrodynamic observations(water depth,wave height,and current velocity)and SSC measurements on the tidal flat off the Huanghe River Mouth.The data shows that in most of time,under the calm sea condition,the SSC ranges 0.1–3.5 g/L,and sediment discharge from the river is the main source.However,when hydrodynamics are enhanced in a tidal cycle and large-scale erosion occurs on the seafloor,resuspended sediment becomes the main source,and the SSC in the water column reaches 17.3 g/L.We find the suspended sediment flux is mainly controlled by the tidal current and Stokes drift,while the wave-induced shear stress could also affect the variation of suspended sediment flux.During the observation period,when sea under calm-rippled conditions,the current-induced resuspended sediment concentration(RSC)was greater than the wave-induced RSC.In contrast,in smooth-wavelet sea conditions,the wave-induced RSC was greater than the current-induced RSC,for instance,a single wave event was found to cause 11.8 cm seabed erosion within 6 h.This study reveals different controlling factors for the high SSC near a river-influenced tidal flat,and helps us get a better understanding of a delta's depositional and erosional mechanisms.
