Quantitying the Systemic Vulnerability of Critical Infrastructure Networks to Volcanic Multi-Hazards at Mt Taranaki, New Zealand

Critical infrastructure are the infrastructural networks and systems deemed essential for the functionality of society and economy. Critical infrastructure systems are globally recognised to be highly interdependent, meaning that the loss of function of an asset within one sector can greatly reduce the functionality of assets that rely on its continued supply. Due to the complexity of such networks, systemic vulnerability (the propensity of a system or network to experience loss of service due to physical damage) is typically qualitatively ascertained, or neglected entirely in impact assessment frameworks. Furthermore, current quantitative methods for systemic vulnerability calculation (such as criticality metrics) tend to be sector-specific, therefore not accounting for trans-sector interdependencies inherent in infrastructural networks. We propose a new methodology for determining asset criticality, incorporating interdependencies inherent in infrastructural networks. We also demonstrate a new methodology for the quantification of systemic vulnerability, by integrating the new asset criticality classification scheme with hazard-plausibility information. We demonstrate this new methodology in Taranaki, New Zealand, where spatially extensive critical infrastructure networks supply substantial agricultural and energy industry, and also circumnavigate Mt Taranaki volcano, where a large explosive eruption in the next 50 years has a 33 – 42 % likelihood