Modelling study of hydrodynamics in a macro tidal estuary

A depth-averaged two-dimensional (2D) numerical model was developed to investigate hydrodynamics in estuaries. The Qiantang estuary is taken as a demonstrative case study. The Qiantang estuary is famous for its macro tide during the spring tide and the Qiantang bore, which poses a challenging task for accurate simulation. In this study, the model was setup to simulate the tidal elevations and the tidal velocity field in the Qiantang estuary. A mesh sensitivity analysis was carried out to optimise the mesh arrangement to achieve computational efficiency while retaining computational accuracy. The simulation results showed that, in general, the numerical simulation agreed well with the field observations, indicating that the developed 2D model can be applied to calculate hydrodynamics in a macro tidal estuary. Some deviation between the simulation and measurements at some locations exists and this discrepancy is analysed and discussed.