Integrative Post-event Impact Assessment Framework for Volcanic Eruptions: A Disaster Forensic Investigation of the 2011–2012 Eruption of the Cordón Caulle Volcano (Chile)

Abstract

Understanding the complexity of future volcanic impacts that can be potentially induced by the large variability of volcanic hazards and the multiple dimensions of vulnerability of the increasingly interdependent and interconnected societies, requires an in-depth analysis of past events. A structured and inclusive post-event impact assessment framework is proposed and applied for the evaluation of damage and disruption on critical infrastructures caused by the eruption of the Cordón Caulle volcano (Chile) in 2011–2012. This framework is built on the forensic analysis of disasters combined with the techniques of the root cause analysis that converge in a bow-tie tool. It consists of a fault tree connected to subsequent event trees to describe the causal order of impacts. Considering the physical and systemic dimensions of vulnerability, four orders of impact have been identified: i) the first order refers to the physical damage or the primary impact on a component of the critical infrastructure; ii) the second order refers to the loss of functionality in the system due to a physical damage on key components of the system; iii) the third order refers to the systemic impact due to the interdependency and connectivity among different critical infrastructures; and iv) a higher order is related to the consequences on the main economic sectors and to social disruption that can activate an overall damage to the economy of the country or countries affected. Our study in the Argentinian Patagonia shows that the long-lasting impact of the 2011–2012 Cordón Caulle eruption is mostly due to a secondary hazard (i.e., wind remobilisation of ash), which exacerbated the primary impact affecting significantly larger areas and for longer time with respect to primary tephra deposition. In addition, systemic vulnerability, particularly the intrinsic dependencies within and among systems, played a major role in the cascading impact of the analysed communities.

Temporal evolution of roof collapse from tephra fallout during the 2021-Tajogaite eruption (La Palma, Spain)

“…To quantify the extent and severity of tephra fallout impacts on roofs and the effectiveness of clean-up operations, we designed a post-eruption impact assessment based on the protocol of Dominguez et al (2021). This methodology includes 4 steps that are i) defining the objectives and level of detail of this study; ii) exploring evidences of impact caused by tephra on the builtenvironment; iii) quantifying impacts based on observations of damage and buildings properties in relation with tephra thickness; and iv) identifying critical aspects that played a major role on reducing impacts (e.g., response actions).…”

Approaching the Challenge of Multi-phase, Multi-hazard Volcanic Impact Assessment Through the Lens of Systemic Risk: Application to Taranaki Mounga

“…Previous studies have generally been focused on hazard, particularly the quanti cation of cascading and interacting hazard relationships and their contribution to potential exposure and impacts (Zuccaro et al 2008;Deligne et al 2017a, b;Dunant et al 2021a, b). There has been comparatively less attention given to integrating exposure, vulnerability and resilience elements of impact and risk within these frameworks (Ordaz et al 2019;Phillips et al 2019;Dominguez et al 2021). Various studies have attempted and noted the di culty in integrating the physical and spatio-temporal characteristics of different hazards to produce an appropriate common metric which can be used within multihazard impact and risk assessment frameworks (Kappes et al 2012;Tilloy et al 2019).…”

Reducing uncertainty in building vulnerability and impact assessment for tephra hazards

“…as the least developed aspect of volcanic risk assessment and therefore the most in need of improvement (Bonadonna et al 2018). Studies of social, economic and systemic vulnerability (Armijos et al 2017;Barclay et al 2019;Wild et al 2019) or of indirect or long-term impacts (Wilson et al 2009;Dominguez et al 2021) are particularly rare, when compared to studies focused on direct physical vulnerability. Reasons why physical vulnerability studies are more common have been proposed by Bonadonna et al (2018).…”

“…where there is either no damage or complete damage based on the presence or absence of a hazard) (Deligne et al 2021). Of all volcanic vulnerability research, that regarding building vulnerability to tephra fall hazards is considered to have received the most research attention (Deligne et al 2021;Wilson et al 2014;Bonadonna et al 2021).…”

“…Additionally, for large-scale eruptions it is important to consider whether communities are likely to return to heavily impacted areas and over what timescales. If communities are to return, the time and resources required to clean-up large volumes of tephra, the impact of tephra falls on local agriculture, the possibility of long-term remobilisation and rain-triggered lahars will all be important aspects to consider at Kelud (Janda et al 1996;Hayes et al 2019b;Wild et al 2019;Dominguez et al 2021).…”