Numerical simulation of sediment dynamics in the Hooghly Estuary

A three-dimensional hydrodynamic numerical model coupled with a sediment transport model has been applied to simulate the estuarine circulations and suspended sediment transport in the Hooghly Estuary under the presence of strong tidal currents and huge freshwater discharge during the monsoon. The model topography has been derived from the depth sounding data assimilated from the hydrographical survey. The observed sediment dataset are incorporated in the model and are validated with different surveys. In the present study, two numerical experiments are conducted by simulating the model with or without the presence of river discharge, along with tidal forcing to understand the ebb-dominance on the transport of suspended sediment concentration in Hooghly Estuary during the southwest monsoon. The simulated results revealed that the dynamics of ample suspended sediment concentration is dominant in areas of high bottom tidal stress of ~3N/m
²
towards the west and southwest of Sagar, Nayachar and Balari Islands.