Modelling tidal-induced sediment transport in a sand-silt mixed environment from days to years: Application to the Jiangsu coastal water, China

• Published in: Coastal engineering (Amsterdam) Vol. 141; pp. 86 - 106
• Main Authors: Yao, Peng, Su, Min, Wang, Zhengbing, van Rijn, Leo C., Zhang, Changkuan, Stive, Marcel J.F.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.11.2018
• Subjects: Jiangsu coast; Sand-silt mixed bed; Sediment transport; Short-term and long-term simulation; Tide; Sand-silt mixed bed; Short-term and long-term simulation; Tide; Jiangsu coast; Sediment transport
• ISSN: 0378-3839; 1872-7379
• DOI: 10.1016/j.coastaleng.2018.09.002

In the present study a new multi-fractional, depth-averaged sediment transport module was developed and embedded into a morphodynamic model for a sand-silt mixed shallow water environment. Subsequently, the model was applied to the case of the Jiangsu coast, which features a silt enriched sedimentary environment bordered by two large-scale geomorphological units: the Old Yellow River Delta (OYRD) in the north and the Radial Sand Ridge Field (RSRF) in the south. Based on this case, the predictive abilities of the present model are assessed on both the short-term and the long-term. Comparisons with measurements over two successive tidal cycles indicate that the present model produces very good results on short-time scales. The model performance is extended and further validated by comparing the overall annual Suspended Sediment Concentration (SSC) pattern, the annual morphological changes, the annual sediment budget and the evolution trend of the bed composition. Also, these long-term results agree well with existing observations over the past several decades. Hence, an essential feature of the present modelling approach is the ability to simulate sediment transport and morphological changes over a relatively long time span (i.e., time scale of years) in a sand-silt mixed sedimentary environment, based on its validated short-term performance. •A multi-fractional sediment model is developed for a silt-enriched environment.•The model is validated for its ability on successively simulate sediment transport over period from days to years.•The simulated long-term sediment dynamics is consistent with observation-based estimates.