Quantifying cascading impacts through road network analysis in an insular volcanic setting: the 2021 Tajogaite eruption of La Palma Island (Spain)

Article Article scientifique Article Quantifying cascading impacts through road network analysis in an insular volcanic setting: the 2021 Tajogaite eruption of La Palma Island (Spain) eng 2025-12-04 author Dominguez Lucia 0000-0002-7093-6555 751781 Services communs du département des sciences de la terre (DETCO) author Biasse Sébastien 0000-0002-1919-9473 583087 Services communs de l'Institut des sciences de l'environnement (ISECO) author Frischknecht Corine 0000-0002-3929-1154 28271 Services communs du département des sciences de la terre (DETCO) author Weir Alana 0000-0001-7449-016X 892644 author Reyes Hardy Maria-Paz 0000-0001-8456-7546 945821 author Di Maio Luigia Sara 944255 Services communs du département des sciences de la terre (DETCO) author Pérez Nemesio author Bonadonna Costanza 0000-0002-2368-2193 636612 Services communs du département des sciences de la terre (DETCO) 4815-4841 10.5194/nhess-25-4815-2025 1561-8633 https://nhess.copernicus.org/articles/25/4815/2025/ Post-event impact assessments (PEIAs) are essential to elucidate disasters' drivers and better anticipate future events. The 2021 Tajogaite eruption of Cumbre Vieja (La Palma, Spain) demonstrated the various orders of impact due to compound volcanic products (i.e., lava, tephra, gas) affecting a highly interconnected and low redundant infrastructure, typical of insular environments. Using a forensic approach, we discretise the causal order of cascading impacts, from physical damage (first order) to loss of functionality of the road network (second order) and subsequent systemic disruption of emergency management and socio-economic sectors (third order). Based on graph theory, we apply a comprehensive network analysis to quantify the loss of functionality and resulting effects, based on the spatiotemporal evolution of centrality indicators. The consequences on dependent systems are expressed in terms of increased driving time syn- and post-eruption between target locations for emergency (evacuation), public health (hospital), agriculture (crops-market), and education (schools). Graph indicators are objective measures of system performance during (disturbing/degraded states) and after the eruption (restorative state), when two new roads where rapidly built to reconnect the island. This study demonstrates how network analyses, informed by comprehensive PEIAs, can accurately capture complex systemic disturbances, thus highlighting its potential for risk assessments. Dewey 550 Dewey 333.7-333.9 Swiss National Science Foundation A new probabilistic framework for regional volcanic risk assessment including hazards interacting at multiple temporal and spatial scales 188757 CH 42 Département des sciences de la Terre 154 18 Institut des sciences de l'environnement 0DB false 667 Physical Volcanology and Geological Risk Natural hazards and earth system sciences 25 12 c08241a7-f324-458f-8aeb-12fd9571e417 Article (Published version) Public Article_scientifique_from_crossref.pdf 12193192 application/pdf CC BY-4.0 c262fd479594ad5d32feda528230fc557357fe9878c8d7ae663fd07a69d3e602 openAccess Faculté des sciences / Section des sciences de la Terre et de l'Environnement / Département des sciences de la Terre Centres et instituts / Institut des sciences de l'environnement

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Quantifying cascading impacts through road network analysis in an insular volcanic setting: the 2021 Tajogaite eruption of La Palma Island (Spain)	Natural hazards and earth system sciences			2025	18	23

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