Discussion about tsunami interaction with fringing coral reef

Abstract

The recent catastrophic tsunamis show that it is now more than ever necessary to assess tsunami hazard for all coastal communities. In fact, facing the dangerous increase of population in low-lying coastal areas during the last decades directly linked to the reduction of the natural defences against sea assaults, including tsunamis, and considering the economy of most of the concerned countries, solutions should be found quickly to protect those populations and/or mitigate the hazard. In that way, recent studies and post-event field observations have highlighted the protective role played by coral reefs and the consequences of their destructions on the tsunami amplitudes. In this study previous results about the effect of fringing coral reef geometry on the tsunami amplitude are discussed using numerical modeling of nonlinear shallow water equations (NAMI-DANCE code). For this purpose, a set of different artificial Digital Elevation Models has been prepared in agreement with real bathymetric profiles and results of simulations are compared and discussed together with the conclusions obtained by the other authors.