Tsunami model simulation for 26 December 2004 and its effect on Koodankulam region of Tamil Nadu Coast

Abstract

Tsunami inundation model ‘TUNAMI-N2’ was set up for five different scenarios of earthquake (Sumatra 2004, Car Nicobar 1881, North Andaman 1941, Makran 1945 and Worst-case) to assess the potential risk of tsunami along Koodankulam coast. Bathymetry and land topography were extracted from the General Bathymetric Chart of the Oceans, C-MAP and CARTOSAT to set up a four-layered nested model, where the finest grid was set up for 93 m in non-linear mode. The aim of the study was to provide the potential run-up and inundation that could occur in worst situation along the Koodankulam coast. The sensitivity analysis was also carried out to assess the effects of various fault parameters. From sensitivity analysis, it is inferred that the tsunami wave height is directly proportionate to slip amount and inversely proportionate to focal depth. The potential tsunami run-up heights were found between 1.30 and 3.54 m and inundation was between 0 and 90 m at Koodankulam and surrounding regions. But, no horizontal inundation was observed for any scenarios around the Koodankulam plant area as the region. The highest run-up heights of five models were used to evaluate the possible vulnerability of power plant for tsunami hazards.