Numerical Simulation of Extreme Sea Levels for the Tamil Nadu (India) and Sri Lankan Coasts

Numerical modeling of extreme sea levels associated with tropical cyclones in the Indian seas has been confined to the northern part of the Bay of Bengal (north of Tamil Nadu). However, limited attempts have been made for modeling of surges along the Tamil Nadu and Sri Lankan coasts. Although, very rarely, cyclones form south of 10°N, there are some instances of severe cyclonic storms hitting these areas and causing widespread destruction to life and property. Keeping this in view, a suitable location-specific, high-resolution, numerical model has been developed for the prediction of storm surges in these regions with a grid resolution of 3 km.

Using the model, numerical experiments are performed to simulate the storm surge associated with the 1964 Rameswaram cyclone, the 1978 Batticaloa cyclone, the 1992 Tuticorin cyclone, the 1993 Karaikal cyclone, and the 1994 Madras cyclone. During the years 1964, 1978, and 1992, the cyclones struck both Sri Lanka and Tamil Nadu coasts, while in 1993 and 1994, the cyclones struck only the Tamil Nadu coast. It is found that the computed sea surface elevations are in close agreement with the available observations/estimates.