16. New Tools for the Analysis of the Generalized Impact of Earthquake Events

Earthquakes and tsunamis continue to be some of the most disastrous natural events. In this review paper, we present the work developed by the Seismic Risks Group of Instituto Superior Técnico (IST) in the last decade, with emphasis on the performance indicators proposed to deal with the effects of natural disasters. Starting with an appraisal of the world earthquake impacts since 1900, the text summarizes the most relevant impact indicators, namely, SIRIUS and disruption indexes (DI) for the urban and industrial fabrics, which includes cascading effects. Also, the early stage of the analysis of multi-hazard, namely for shaking and tsunami events, is reviewed. Finally, we use these impact indicators in conjunction with performance indicators (RRW – risk reduction worth and RAW – risk achievement worth) to communicate the risk to the population and mitigate the action of future events. Several conclusions can be taken from the work developed. The most important is that earthquake impacts cannot be measured only by human losses and losses to property, but indirect and cascading effects also play a huge role in the global impact, especially in moderate to large events.