Unraveling the impact of sediment size distribution on flow-sediment hysteresis in estuarine environments: insights from size-resolved sediment transport modeling

• Published in: Environmental Research Communications Vol. 7; no. 6; pp. 61011 - 61026
• Main Authors: Fang, Zheng, Xu, Fanghua, Zhang, Xueyang
• Format: Journal Article
• Language: English
• Published: Bristol IOP Publishing 01.06.2025
• Subjects: Correlation analysis; Estuaries; estuarine environment; Estuarine environments; Flocculation; flow-sediment hysteresis; Hysteresis; numerical simulation; Prediction models; Sediment transport; Size distribution; size-resolved sediment transport model; Tidal cycles; Tides
• ISSN: 2515-7620; 2515-7620
• DOI: 10.1088/2515-7620/ade49a

Flow-sediment hysteresis, a nonlinear time-lagged relationship between sediment transport and hydrodynamic conditions, is particularly important yet difficult to simulate in tidal estuarine environments. This study introduces a size-resolved sediment transport model to simulate flow-sediment hysteresis, with an application in the Hudson River estuary. By incorporating variations in sediment size distribution induced by flocculation, the model allows for a more accurate simulation of flow-sediment hysteresis compared to traditional size-fixed models, achieving accuracy improvements of 4.89% ∼ 12.19% during tidal cycles. Moreover, budget analyses and correlation matrix analyses are conducted. The results indicate that the dynamics of small and large flocs influence hysteresis differentially: flocculation processes dominate the behavior of small flocs, while settling and vertical diffusion processes primarily affect large flocs. These insights offer a deeper understanding of sediment transport in tidal estuaries, providing a robust framework for enhanced predictive modeling which can be adapted to other estuarine environments.