Evaluation of tsunami vulnerability along northeast coast of India

Abstract

The Sumatra tsunami of 26 December 2004 with a moment magnitude of 9.3 Mw caused colossal damage to the south-southeastern Indian coast and Andaman–Nicobar group of Islands. However, the northeastern coastline bordering the northwestern Bay of Bengal remained unaffected although a tidal station located in the region recorded the highest water level (~2.5m) for the entire east coast of India on the eventful day. As a part of hazard mitigation and planning for the northeastern coast, four major settlements, viz., Gopalpur, Puri, Paradip and Digha were evaluated for tsunami vulnerability. Inundation and run-up scenarios were generated for Bay of Bengal earthquake sources such as Arakan-1762, Car Nicobar-1881, North Andaman-1941 and Sumatra 2004 using TUNAMI N2 model. The paper describes computed run-up heights and landward inundation for 20–25km coastal stretch with different geomorphologies and topographical characteristics. Simulation results indicate that the model is able to generate a comparable run-up of 2–4.5m for 2004 Sumatra event for Paradip region while at other locations of the coastline, it was largely unnoticed as the inundation remained within the beach limit; however water entered inland mainly through the waterways and inundated low-lying areas. It is concluded that northeast coast of India is relatively safe from the tsunami originating in Bay of Bengal region.