Tsunami hazards: energy dissipation and impact mitigation using bio shields

Abstract

Tsunamis can cause severe destruction in coastal areas. Though the tsunami hazard itself cannot be mitigated nor eliminated, the vulnerable element can be protected by a variety of mitigation measures. Bio shields, including coral reefs, coastal sand dunes and vegetation have been known to provide protection against tsunami inundation. The protection provided by bio shields was evident after the Indian Ocean Tsunami in 2004 in many of the countries affected.*In view of these circumstances, attention was focused in this study to identify the capacity of protection provided by bio shields. Small scale physical model tests have been carried out to identify the mitigation characteristics of bio shields in the form of coastal vegetation. This study focused on detailed analysis of the results obtained by model tests. The protection capacity offered by the vegetation was assessed by considering two aspects, namely energy dissipation and reduction in the extent of inundation.