Numerical investigation of tide‐surge interaction in Hooghly Estuary, India

This article describes the numerical modeling of the tide‐surge interaction in Hooghly Estuary along the east coast of India. Nonlinear, vertically integrated numerical models are used to simulate the combined tide and surge response. The pure tidal solution developed in Hooghly Estuary provides the initial conditions for the model. The storm‐tide frequency calculation consists of generating surge by a given cyclone at the mouth of the estuary using a numerical model developed for the Bay of Bengal. The computed surge is then combined with the astronomical tide at the entrance of the estuary and the calculation continues within the estuary. However, this study does not include the feedback from the estuary on the surge model, hence the interaction is one way. Numerical experiments are performed involving three cyclonic storms, having landfall points to the south of the estuary, at the mouth of the estuary, and to the northeast of the estuary. The comparison, although utilizing only the observed tidal data, appears reasonably well to assert that the principal features are reproduced correctly and are in agreement with theoretical studies.

Keywords:

• Bay of Bengal
• Hooghly Estuary
• numerical model
• salinity intrusion
• tide‐surge interaction