Hydrodynamic Calibration of a Mixed Fluvial-tidal Delta Numerical Model: The Case of Changjiang Estuary

Estuaries and deltas across the globe are instrumental for environmental, economic, and socio-cultural activities. Understanding their evolution, sediment fluxes and morphological characteristics requires well-calibrated and representative numerical models capable of explicitly represent their physics. This work introduces a new hydrodynamic model for the Changjiang Estuary that has been used as the basis for studying the surrounding wetlands evolutions. The numerical model has been developed using a combination of Delft3D and Open-DA. The model has been calibrated using 15 stations across the entire domain, including part of the tidally affected portion of the river, together with discharge measurements for Datong gage station for the period from 25 July to 24 August 2007. The results show the ability of the model to represent the hydrodynamic of the estuary with a high level of accuracy compared to tidal stations across most of the domain. They also highlight the main processes of circulation across the wetlands and can be used for predicting wetlands evolution and sediment provenance across the region.