Tsunami risk reduction – are we better prepared today than in 2004?

Abstract

With over 220,000 fatalities, the 26 December 2004 Indian Ocean tsunami was one of the deadliest natural hazard events ever, and represents a landmark in disaster risk reduction governance in several ways. The 2004 Indian Ocean tsunami led to a better understanding of the likelihood of tsunami occurrence and potential tsunami inundation. For example, the Hyogo Framework Agreement was a direct result of this event. Since December 2004, Indonesia, Samoa, Chile and Japan were hit by altogether six destructive tsunamis in 2006, 2007, 2009, 2010 and 2011.This article looks into the progress (or lack thereof) made in tsunami risk reduction at the local level during the past ten years, with focus on the densely populated coastal regions of Indonesia and Sri Lanka. The experience from other countries, as well as the progress made in the state of the art for assessment of tsunami hazard, vulnerability, exposure and risk are also summarized. In addition, extensive new warning systems enabling a rapid assessment of the potential coastal impact of a tsunami have been developed and implemented. However, the experience from the tsunami events in October 2010 in Indonesia and March 2011 in Japan clearly demonstrated that the tsunami risk mitigation measures implemented to date are far from adequate. The article also examines the progress in assessing and factoring in vulnerability aspects in tsunami risk reduction, highlighted through two case studies in Padang (Indonesia) and Galle (Sri Lanka). In this regard, societal awareness and behavioural response to tsunamis are addressed. Recommendations about how the improved knowledge about tsunami hazard, vulnerability and exposure assessment gained over the past decade could be better implemented into tsunami risk reduction measures are provided at the end of the article.