Numerical analysis of the influence of saltwater intrusion on the deepwater channel in the changjiang estuary

Since 2005, the increased quantity of back silting in the Deepwater Channel has a negative effect on shipping. This research sets up a 2D current model for the Changjiang River estuary using Delft3D-FLOW. The model is well calibrated and verified by applying the observed data of tidal levels and velocities, i.e. the water level, flow velocity magnitude and direction computed from the model agree well with the real measured data. In order to explore the influence of saltwater intrusion on the Deepwater Channel in the Changjiang Estuary, the computed velocity along the Deepwater Channel, the horizontal and longitudinal salinity distribution in the Deepwater Channel in the dry and wet season are analyzed. Analyzed results show that the fine suspended sediment flocculates easily in the upper reach of the Deepwater Channel beyond Hengsha Island in dry season, which increases sediment's falling and deposition in this region.