Multi-indicator building vulnerability index for assessing tsunami-induced building damages

While relatively uncommon, tsunami typically leads to extreme and devastating impacts to human lives and development at far distances. Various international bodies and academic research have highlighted the importance of understanding risk and its determinants for effective risk management. Currently available methodologies to assess tsunami risk and the effect of vulnerability towards the resulting impact present opportunities for improvement particularly in their adaptability, accuracy and generalisability for pre- and post-disaster applications, as well as across temporal and geographical boundaries. This paper discusses the potential of a methodology to assess tsunami risk for buildings based on their vulnerability level, which in turn is determined through a set of vulnerability indicators. A vulnerability index equation consisting of four indicators namely building materials, number of storeys, coastal protective structures and coastal vegetation was formulated through the Analytical Hierarchy Process. The index is then applied for two major yet distinctly different tsunami events for the purpose of examining potential links between hazard intensity measure, building vulnerability and recorded impacts while also establishing basis for generalisability. While certain correlations can be observed, the findings are still at preliminary stage and thus approaches to further refine the index were proposed.