Dr. Aranguiz-Muñoz, Rafael

In 2015 and 2017 unusual ocean and atmospheric conditions produced many years’ worth of rainfall in short periods over Northern Chile’s Atacama Desert, resulting in catastrophic flooding in the town of Chañaral. However, the town is not only at risk of fluvial flooding, it is also at risk of tsunamis. Through a community mapping exercise, the authors attempted to establish the level of community awareness about tsunamis, and contrasted it with that of other types of water-related hazards facing the town (namely that of flooding due to high intensity rain). This was then compared with the results of field surveys and tsunami hazard simulations, indicating than overall the community appears to have better awareness than authorities about the threat posed by these types of events. The authors thus concluded that in cases when the community has a high level of hazard awareness (which in the case of Chile was the result of traditional knowledge being transmitted from previous generations) it would be advantageous to include them in discussions on how to improve disaster resilience.

The Sendai Framework for Disaster Risk Reduction emphasizes the need to rebuild better after a disaster to ensure that the at-risk communities can withstand a similar or stronger shock in the future. In the present work, the authors analyzed the reconstruction paths through a comparative analysis of the perspective of a community in Japan and another in Chile, and their respective local governments. While both countries are at risk to tsunamis, they follow different reconstruction philosophies. Data was gathered through key informant interviews of community members and local government officials, by adapting and modifying the Building Resilience to Adapt to Climate Extremes and Disasters (BRACED) 3As framework to a tsunami scenario. The 3As represent anticipatory, adaptive, and absorptive capacities as well as transformative capacities and respondents were asked to rate this according to their perspectives. It was found that while both communities perceive that much is to be done in recovery, Kirikiri has a more holistic and similar perspective of the recovery with their government officials as compared to Dichato. This shows that community reconstruction and recovery from a disaster requires a holistic participation and understanding.

This study assesses physical infrastructure vulnerability for infrastructure network components exposed during the 2015 Illapel tsunami in Coquimbo, Chile. We analyse road and utility pole vulnerability to damage, based on interpolated and simulated tsunami hazard intensity (flow depth, flow velocity, hydrodynamic force and momentum flux) and network component characteristics. A Random Forest Model and Spearman’s Rank correlation test are applied to analyse variable importance and monotonic relationships, with respect to damage, between tsunami hazards and network component attributes. These models and tests reveal that flow depth correlates higher with damage, relative to flow velocity, hydrodynamic force and momentum flux. Scour (for roads and utility poles) and debris strikes (for utility poles) are strongly correlated with damage. A cumulative link model methodology is used to fit fragility curves. These fragility curves reveal that, in response to flow depth, Coquimbo roads have higher vulnerability than those analysed in previous tsunami event studies, while utility poles demonstrate lower vulnerability than with previous studies. Although we identify tsunami flow depth as the most important hydrodynamic hazard intensity metric, for causing road and utility pole damage, multiple characteristics correlate with damage and should also be considered when classifying infrastructure damage levels.