Research on Instantaneous Sediment Concentration in Muddy Coastal Waters Under Extreme Weather Conditions

This study addresses a fundamental limitation inherent in conventional sediment transport capacity formulas—their failure to accurately capture real-time fluctuations in suspended sediment concentration. Leveraging extensive synchronous field measurements of waves, currents, and sediment dynamics from muddy coastal zones, we integrate theoretical derivation with comprehensive data analysis to investigate the complex and transient behavior of instantaneous sediment concentration under extreme weather conditions. This study elucidates the dynamic response mechanisms of instantaneous sediment concentration to wave–current interactions, culminating in a novel formulation that incorporates the effects of velocity phase lag and wave energy dissipation. Validation against field measurements demonstrates that the proposed formula shows marked improvement over traditional sediment transport formulas in predicting sediment concentration during extreme events. This advancement provides more reliable sediment boundary conditions for numerical sediment transport modeling and establishes a new methodological framework for investigating sediment dynamics in muddy coastal environments.