Tsunami evacuation analysis in the urban built environment: a multi-scale perspective through two modeling approaches in Viña del Mar, Chile

Abstract

In the case of near-field tsunami emergencies, evacuation is considered the most important and effective method to save human lives. While significant efforts have been carried out to examine tsunami evacuation within the urban built environment, challenges remain on delivering a more detailed examination of the latter’s suitability for this task, and on addressing different scales of analysis. Along these lines, this paper draws upon a multi-scale framework for examining resilience of the urban form, to carry out a multi-scale tsunami evacuation analysis of the Great Valparaíso Metropolitan Area (GVMA) and the city of Viña del Mar, Chile, supported by both LCD and agent-based modeling approaches. The results show a significant macro-scale tsunami exposure of some areas in the territory, particularly in the Población Vergara and downtown neighborhoods. In line with this, the meso-scale evacuation analysis shows moderate escape rates (as low as 61.4%) in these areas. Moreover, the comparison between the models’ outcomes show that micro-scale vulnerabilities can potentially increase evacuation travel times by roughly 11%. These results, however, are noticeably dependent on the modeling choice.