Sediment dynamic response of tidal flats in the Yellow River estuary under storm events: insights and prospects

The Yellow River Delta, characterized by high sediment discharge, frequent human activities, and recurrent storm events, serves as a typical region for studying tidal flat changes under multiple stressors. This paper systematically synthesizes previous research on storm-induced sediment dynamic processes in the Yellow River Estuary’s tidal flats and analyzes emerging challenges arising from the combined effects of storms and human activities. During storms, hydrodynamic characteristics, sediment transport, and erosion-deposition patterns exhibit significant spatial heterogeneity across the delta. Wave effect dominates sediment resuspension on tidal flats near the current river estuary, while currents controlled by wind-driven flows and storm surges are prominent along the Diaokou and Laizhou Bay areas. Under prevailing northeasterly or northerly winds, onshore sediment transport and accretion trends are observed in the Diaokou and western current estuary regions, whereas offshore transport dominates along Laizhou Bay. Human interventions further modulate storm-driven sediment dynamic responses: salt marsh vegetation, particularly Spartina alterniflora, enhances sediment deposition, yet its removal projects may exacerbate storm-induced erosion risks. The synergistic effect of pulsed sediment discharge during Water-Sediment Regulation and onshore storm events can amplify tidal flat accretion efficiency. Against the backdrop of increasing storm frequency and poleward migration, future studies should prioritize investigating the combined effects of human interventions and storm events, as well as seasonal variations in storm impacts, to provide scientific support for ecological conservation and hazard mitigation in the tidal flats of the Yellow River Delta.