Print Email Facebook Twitter Study of Sediment Transport in a Tidal Channel-Shoal System Title Study of Sediment Transport in a Tidal Channel-Shoal System: Lateral Effects and Slack-Water Dynamics Author Zhou, Z. (TU Delft Coastal Engineering; East China Normal University) Ge, Jianzhong (East China Normal University; Institute of Eco-Chongming (IEC)) van Maren, D.S. (TU Delft Environmental Fluid Mechanics; East China Normal University; Deltares) Wang, Zhengbing (TU Delft Coastal Engineering; Deltares) Kuai, Y. (TU Delft Coastal Engineering) Ding, Pingxing (East China Normal University) Date 2021 Abstract Lateral flows redistribute sediment and influence the morphodynamics of channel-shoal systems. However, our understanding of lateral transport of suspended sediment during high and low water slack is still fairly limited, especially in engineered estuaries. Human interventions such as dike-groyne structures influence lateral exchange mechanisms. The present study aims to unravel these mechanisms in a heavily engineered, turbid channel-shoal system in the Changjiang Estuary, using a high-resolution unstructured-grid three-dimensional model and in situ observations. Analysis of model results reveals two typical transport patterns during slack-water conditions, that is, shoal-to-channel transport during low water slack and channel-to-shoal transport during high water slack. A momentum balance analysis is carried out to explain mechanisms driving the lateral transport of suspended sediment during high water slack, revealing the importance of lateral pressure gradients, Coriolis force, and the curvature-induced term. Groyne fields play a crucial role in sediment transport, especially during low water slack. A model scenario in which one groyne is removed reveals that groyne fields strongly influence lateral sediment transport. The decomposition of the sediment transport flux reveals that the turbidity maximum is shaped by a balance between seaward advection by residual flows, and landward transport by tidal pumping and gravitational circulation. Within the turbidity maximum, sediment is laterally redistributed by lateral flows during slack-water conditions, greatly influencing estuarine channel morphology. Subject groyne fieldslateral flownumerical modelsalinity gradientsediment transportslack-water dynamics To reference this document use: http://resolver.tudelft.nl/uuid:1fb4e494-5f33-4695-88cc-e687dc961558 DOI https://doi.org/10.1029/2020JC016334 Embargo date 2021-08-20 ISSN 2169-9275 Source Journal Of Geophysical Research-Oceans, 126 (3), 1-23 Part of collection Institutional Repository Document type journal article Rights © 2021 Z. Zhou, Jianzhong Ge, D.S. van Maren, Zhengbing Wang, Y. Kuai, Pingxing Ding Files PDF 2020JC016334.pdf 7.09 MB Close viewer /islandora/object/uuid:1fb4e494-5f33-4695-88cc-e687dc961558/datastream/OBJ/view