Two-dimensional characteristics of hydrodynamics and sediment transport in the Pearl River Estuary

A two-dimensional depth-integrated model was used to investigate the tidal-induced characteristics of hydrodynamics and sediment transport in the Pearl River Estuary (PRE). A computation domain with far enough open-sea boundaries was adopted which aimed to alleviate the errors induced by inaccuracy of open-sea boundary conditions. The computed hydrodynamic results were compared with measurements. In general, the computed results were in good agreement with the observed data. Based upon the computed results, some hydrodynamic processes such as the tidal process, current and residual flows in the PRE were analyzed. Computed results showed that the Eulerian residual flows are mainly due to runoff from the Pearl Rivers and the Stokes drifts are due to tidal asymmetry. Furthermore, spatial distribution of vertically averaged suspended sediment concentration was studied and compared with satellite imagery. The phenomenon that the sediment-laden flow in the main channels appears to be clearer than that in shoals was explained through the analysis of sediment-carrying capacity of flow.