Computational investigation on hydrodynamic and sediment transport responses influenced by reclamation projects in the Meizhou Bay, China

Abstract

Reclamation projects are the main method of coastal exploitation, and the hydrodynamic environmental effect, together with the sediment transport response of the reclamation project, is important to the project’s site selection and environmental protection. Herein, a 3D numerical model based on the finite volume community ocean model (FVCOM) is applied to simulate the changes in the Meizhou Bay’s hydrodynamic environment and sediment transport after a reclamation project. The reclamation project greatly alters the shape of the shoreline and narrows the bay, leading to a significant change in its hydrodynamic environment and sediment transport. After the project, the clockwise coastal residual current in the corner above the Meizhou Island gradually disappears. An obvious counter-clockwise coastal residual current emerges around the rectangular corner. The tidal prism decreases by 0.65 × 109 and 0.44 × 109 m3 in the spring and neap tides, respectively. The residence time presents a major increase. These changes lead to the weakening of the water exchange capacity and the reduction of the self-purification capacity of the bay. Currents in the tidal channel weaken, whilst currents in the horizontal channel strengthen. The strength and scope of particle trajectories around the horizontal channel and the Meizhou Island enhance. The suspended sediment concentration (SSC) increases in the majority of the Meizhou Bay but decreases in the lateral bay. The eastern corner of Z2 shows a tendency to erode. The western region of the Meizhou Island, the upper portion of the rectangular corner and the western corner of Z4 show a tendency to deposit. The reclamation project increases the maximum storm surges by 0.06 m and decreases the maximum significant wave heights by 0.09 m.