An accessibility graph-based model to optimize tsunami evacuation sites and routes in Martinique, France

Abstract

Abstract. The risk of tsunami threatens the whole Caribbean coastline especially the Lesser Antilles. The first available models of tsunami propagation estimate that the travel time from the closest seismic sources would only take few minutes to impact the Martinique Island. Considering this threat, the most effective measure is a planned and organized evacuation of the coastal population. This requires an efficient regional warning system, estimation of the maximum expected tsunami flood height, preparation of the population to evacuate, and drawing up of local and regional emergency plans. In order to produce an efficient evacuation plan, we have to assess the number of people at risk, the potential evacuation routes, the safe areas and the available time to evacuate. However, this essential information is still lacking in the French West Indies emergency plans. This paper proposes a model of tsunami evacuation sites accessibility for Martinique directly addressed to decision makers. It is based on a population database at a local scale, the development of connected graphs of roads, the identification of potential safe areas and the velocity setting for pedestrians. Evacuation routes are calculated using the Dijkstra's algorithm which gives the shortest path between areas at risk and designated evacuation sites. The first results allow us to map the theoretical times and routes to keep the exposed population safe and to compare these results with a tsunami travel time scenario.

A spatial and integrated flood risk diagnosis

“…Several criteria for refuge zones are proposed, such as altitude, availability, capacity and connectivity. The followed methodology was adapted from Péroche et al (2014) for tsunami evacuation plan. The graphical design of the evacuation map prototypes follows symbolization rules optimized by Girres et al (2018).…”

Integrating spatial accessibility in the design of volcano evacuation plans in the French West Indies (Guadeloupe and Martinique)

“…Small islands like Martinique and Guadeloupe are furthermore highly dependent on external resources and on their road networks that are essentially coastal and with low connectivity, and highly exposed to lahar-prone rivers draining radially from the central mountainous areas. By contrast, good road accessibility will promote an efficient preventive evacuation process (Péroche et al 2014), the support of populations after a disaster (Ukai 1997), and territorial resilience by accelerating a return to a normal situation (D'Ercole et al 2012;Zaninetti, 2013).…”

Spatio-Temporal Modeling of Human Vulnerability in the Case of a Tsunami in Padang, Indonesia

“…In addition to the width, Leone et al ( 2012) added other factors, such as the kind of ground surface, occupation rate, land slope, and presence of abrupt constrictions. Taking into account these elements, like (Péroche, Léone, and Gutton 2014), we experimentally evaluated the walking speeds varying between 0.5 m/s to 1.2 m/s in Padang. Furthermore, we distinguished walking speed during slow hours and peak hours to model congestion phenomena.…”