Evaluation of Tsunami Risk at Selected Locations of South Andhra coast (East Coast of India) based on Numerical Modeling and Field Observations

Abstract

The Andhra coast is well known for cyclones and less known for tsunamis. The December 26, 2004, Sumatran Indian Ocean tsunami, created considerable damages along the south Andhra coast, especially along the Krishnapatnam, Kavali, and Ongole coasts. Of these, Krsihnapatnam and Kavali were the most affected and have experienced run-up levels of 1.9 m and inundation distances of 200–1350 m. In places of straight coast, the tsunami run-up was limited to berm level (200–400 m from the shoreline) whereas in places occupied by creeks, inlets, and river mouths the run-up extended far inland up to 600–1350 m. The TUNAMI-N2 model simulations on propagation times, run-up, and inundation distances along Krishnapatnam, Kavali, and Ongole coasts are well agreed with the observed features of tsunami. The travel times of Sumatra 2004 tsunami to reach the shore along the three coasts are 175, 180, and 190 minutes, respectively, which are reproduced well in model simulations. Evaluation tsunami hazard levels along the three coastal sites are discussed in terms of run-up as most of the villages, public places, and shrimp culture ponds are located within 1–1.5 km of the shoreline.