Evaluating building exposure and economic loss changes after the 2009 South Pacific Tsunami

This study evaluates changes to building exposure and economic loss from tsunami in southeast Upolu Island, Samoa. A deterministic tsunami loss model was configured to estimate building exposure and conditional probabilities of building damage and direct economic loss for two temporal periods before and after the 2009 South Pacific Tsunami (SPT). A simulated 2009 SPT inundation scenario and building inventories representing each period show a small (4%) loss reduction after the 2009 SPT. In the ten years after the event we observed a >90% probability that residential dwellings sustain a loss reduction of USD $9 million, while hotel and resort building losses more than tripled to USD $6 million. The observed building damage and economic loss change reflect the social and economic drivers of post-2009 SPT recovery. Economic losses for several coastal villages impacted by the 2009 SPT reduced in response to ?build back and relocate? measures, moving buildings to higher elevations. Conversely, increasing tourism led to hotel and resort building ?build back? on coastal land exposed to the simulated 2009 SPT inundation. Tsunami loss models that quantify spatio-temporal building damage and economic loss change can assist disaster risk managers to plan and implement community and sector appropriate tsunami mitigation measures.