On the patterns and mechanisms of residual currents and suspended sediment transport in the Lingdingyang of the Pearl River Delta
Year: 2024
Type: article
Abstract: • Seaward Eulerian residual currents are the dominant role in transporting material like sediment and pollutants in the Lingdingyang estuary. • Significant seasonal variations existed in residual currents and sediment transport, with more activity observed during the wet season. • Vertical circulation structure of residual currents is influenced by the estuary's shoal and channel topography. • Advection is the main force in sediment transport, sidelining other mechanisms like tidal pump effects. Tide-averaged current, i.e., Eulerian residual current (ERC), indicates net transport of sediment and pollutants in coastal and estuarine regions. In this paper, we examine the dynamics of tidal currents and associate residual currents (RCs), suspended sediment transport and its governing mechanisms in the Lingdingyang (LDY) of the Pearl River Delta based on field data and numerical modeling. Results indicate that seaward ERCs dominate throughout the LDY. The ERCs are greater in the wet seasons than that in the dry seasons. The ERCs are smaller in the middle layer of the water column over the shoals, whereas they ware are larger in the middle layers in deep channels. The ERCs mainly discharge into the sea through the deep channel and west shoal, forming a slack water zone in the middle shoal. Vertical circulation structures of ERCs are controlled by the channel-shoal structure. A dual ERC circulation structure was observed between the channels, which is characterized with seaward and landward ERCs at the surface and bottom layers, respectively. As a result, the residual sediment transports are seaward, with large rates at the shoal than in the channel. Seaward ERCs explain residual sediment transport in the deep channel. Both ERCs and Stokes RCs (SRCs) are important over the shoal. Tidal pumping is of secondary importance and its direction varies over time and in space. These findings provide a scientific basis for understanding the channel-shoal evolution and maintenance of the navigational waterway in the LDY.
Source: Sustainable Horizons
Institutions: Sun Yat-sen University, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Department of Natural Resources of Guangdong Province, Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), State Key Laboratory of Estuarine and Coastal Research, East China Normal University, Guangzhou Railway Polytechnic, Hohai University, Guangdong University of Technology, Ollscoil na Gaillimhe – University of Galway
Language: English
Topic: Coastal and Marine Dynamics
Subfield: Earth-Surface Processes
Field: Earth and Planetary Sciences
Domain: Physical Sciences
Open Access status: hybrid
Estimated APC paid: $2,000
OpenAlex ID: W4402707662