Analysis and validation of the PTVA tsunami building vulnerability model using the 2015 Chile post-tsunami damage data in Coquimbo and La Serena cities

Chile is highly exposed to tsunami hazard from large earthquakes often occurring along the Peru-Chile trench, like the 16 September 2015 event. However, only recently has tsunami hazard been considered in the land-use policies of the Chilean coast. These new regulations must enforce the identification of the most vulnerable sectors of the Chilean coastal cities. This paper analyses and validates the two latest versions of the Papathoma Tsunami Vulnerability Assessment (PTVA) model in the 2015 tsunami reconstructed scenario in the cities of La Serena and Coquimbo. Both models result in a similar number of very high and high relative vulnerability index (RVI) scores. However, the less vulnerable categories do not show a similar trend and the PTVA-4 model obtains a larger number of minor and average RVI scores. When compared to the damages caused by the tsunami, the PTVA-3 shows a more similar distribution to the actual damages than that obtained by the PTVA-4 model, which shows a more concentrated distribution of the RVI scores. These results suggest this version of the model should be used in Chilean coastal cities in future land-use or mitigation planning.