Application of simulation methods to understand tsunami processes around the coastal region of Sri Lanka

Abstract

Tsunami is one of the most devastating natural disasters which cannot be prevented or precisely predicted even with the modern advanced technology. One of the best solutions for prediction as well as for the risk analysis of this natural disaster is Numerical Modelling. Present study focuses on the generation of earthquake induced different Tsunami scenarios from the potentially high amplitude earthquake generation zones in the Indian Ocean using Tsunami numerical modelling. Simulation modelling for different scenarios was carried out for source, propagation and inundation using UNESCO/IOC recommended interfaces of AVI NAMI and ComMIT, which uses TUNAMI N2 model. Etopo 2, JEBCO (combine SRTM, ETOP2 and Sea Map data) were used for bathymetry analysis. Distribution of wave heights, run up heights for given locations and arrival times of the waves were simulated as output data. Different Tsunamis were simulated, taking Java Sumathra and Macrum zones as Tsunami sources. Wave heights and propagation of Tsunami waves around twelve locations of Sri Lanka were analysed and vulnerable areas for different scenarios were identified. Results further indicated that if a Tsunami is triggered at Java-Sumatra, Southern part of Sri- Lanka will be severely affected, and particularly the Yala region, because of the direct hit of the Tsunami waves. ComMIT simulation results showed strong coupling to Tsunami sediment data and actual tidal records for 26th December 2004 Tsunami. Therefore, ComMIT seems to be one of the best models for Tsunami warning and forecasting in Sri Lanka.