Computation of Expected Total Water Levels along the East Coast of India

Abstract

Extreme sea levels generated by strong tangential wind stress and normal atmospheric pressure gradients at the sea surface due to tropical cyclones were studied for the western sector of the Bay of Bengal (the east coast of India). The maritime states along the coast, hit by different intensities of cyclones, are West Bengal, Orissa, Andhra Pradesh, and Tamil Nadu. Based on precise historical data for the period 1891–2007, statistical projections have been made on the probable intensities of tropical cyclones for various return periods. With the help of numerical models developed at Indian Institute of Technology Delhi, maximum probable surges along the coast were simulated. The local tide effect was considered in the computations as rise of sea level would be greater if the cyclone crosses the coast during high tide. The total water elevation is computed by linearly adding the local tide and wave setup to the surge simulated along the coast. In the present study, an assessment of cyclone risk and vulnerability was evolved, which is an important component of the information used to create sustainable local-level development action plans for preparedness and mitigation.