Numerical study of the circulation and sediment transport in the Mahanadi estuary

The Mahanadi River is one of the largest river systems in the east coast of India and the estuary drains and communicates with the Bay of Bengal. The seasonally varying fresh water river discharge and the intrusion of salt water from the bay depend on the flow associated with the semi-diurnal component of the astronomical tide (dominated by M-2 component). A numerical model has been developed to simulate and study the salinity structure, velocity profile, flow and circulation pattern and have been compared with the observed data. A reasonably good agreement is noticed between the model simulations and the observations. The model result has been utilised to compute sediment load transport to the estuary channel over a tidal cycle as well as on a monthly time scale. The sediment load transport owing to monthly climatological rainfall is discussed and it is inferred that a dynamic equilibrium exists on a long-term over good/bad monsoons.