Numerical modelling for assessment of tsunami hazards and mitigation measures using geospatial technology

Abstract

The 2004 Indian Ocean tsunami had a significant impact on the Tamil newlineNadu coast, India. This was one of the deadliest natural disasters in recent era. newlineThe tsunami was triggered by a magnitude of 9.3 earthquake nearby Sunda Arc. newlineThe Nagapattinam coast had a highest number of fatalities (6, 501) and 206 in newlineChennai. In this tropical region, lack of a study has reported on tsunami newlinenumerical modelling based on the spatially varying (non-uniform) bottom newlinefriction modelling with climate change induced sea level rise (SLR). In this newlinecontext, a detailed tsunami inundation modelling was carried out and analysed to newlineovercome the weakness observed in the previous studies on site specific. newlineThe present study addresses the modelling of the tsunami wave towards Chennai and Nagapattinam coasts. The tsunami wave propagation numerical modelling was carried out by MIKE21 HD model using coarser grid resolution (6561 m). The tsunami wave arrival time at Tamil Nadu coast was newlinevalidated with tide gauge data and post-tsunami field survey from the literature newlinereview. An extensive literature review was carried out on post-tsunami field newlinesurvey conducted by various teams along the Tamil Nadu coast. The field newlineobservation points provided in the literature was extracted and manual correction newlinewas done for the points which are falling offshore. The compiled dataset for newlineTamil Nadu coast was plotted and analysed, which shows that, Chennai, newlineCuddalore, Nagapattinam and Kanyakumari coast are having more impact newlineduring 2004 Indian Ocean tsunami.For detailed analysis, the nested grid model approach was setup with newlinesix different grid resolutions by following hierarchical structure and analyses newlinewas done in finer grid resolution (27 m). The bottom friction at shallow water newlineregion is one of the important parameter in the tsunami wave modelling. newline newline newline