Lava flow hazard map of Piton de la Fournaise volcano

Piton de la Fournaise, one of the world's most active basaltic shield volcanoes on La Réunion island, poses significant lava flow hazards, particularly outside its uninhabited Enclos caldera. A new study presents an up-to-date lava flow hazard map for the volcano, highlighting that while the majority of eruptions (95%) occur within the Enclos—visited by over 100,000 people annually—the probability of future lava flows remains low (< 0.1%) in inhabited areas outside this region. The map, based on vent distribution, recurrence times, lava flow statistics, and simulations using the DOWNFLOW model, indicates up to 12% inundation probability within the Enclos but only 0.5% along active rift zones outside it. However, the study acknowledges potential underestimation due to limited historical records and suggests that atypical large-volume eruptions could pose greater risks than currently modeled. Regular updates of digital elevation models (DEMs) are recommended to maintain accurate hazard assessments for land use planning and risk mitigation.

Chevrel, M. O., Favalli, M., Villeneuve, N., Harris, A. J. L., Fornaciai, A., Richter, N., Derrien, A., Boissier, P., Di Muro, A., & Peltier, A. (2021). Lava flow hazard map of Piton de la Fournaise volcano. Natural Hazards and Earth System Sciences, 21(8), 2355–2377. https://doi.org/10.5194/nhess-21-2355-2021