Volcanic hazards at distant critical infrastructure: A method for bespoke, multi-disciplinary assessment
Abstract:Societies rely on critical services such as power, water, transport networks and manufacturing. Infrastructure may be sited to minimise exposure to natural hazards but not all can be avoided. The probability of long-range transport of a volcanic plume to a site is comparable to other external hazards that must be considered to satisfy safety assessments. Recent advances in numerical models of plume dispersion and stochastic modelling provide a formalized and transparent approach to probabilistic assessment of hazard distribution. To understand the risks to critical infrastructure far from volcanic sources, it is necessary to quantify their vulnerability to different hazard stressors. However, infrastructure assets (e.g. power plantsand operational facilities) are typically complex systems in themselves, with interdependent components that may differ in susceptibility to hazard impact. Usually, such complexity means that risk either cannot be estimated formally or that unsatisfactory simplifying assumptions are prerequisite to building a tractable risk model.
We present a new approach to quantifying risk by bridging expertise of physical hazard modellers and infrastructure engineers. We use a joint expert judgment approach to determine hazard model inputs and constrain associated uncertainties. Model outputs are chosen on the basis of engineering or operational concerns. The procedure facilitates an interface between physical scientists, with expertise in volcanic hazards, and infrastructure engineers, with insight into vulnerability to hazards. The result is a joined-up approach to estimating risk from low-probability hazards to critical infrastructure. We describe our methodology and show preliminary results for vulnerability to volcanic hazards at a typical