Vulnerability curves for buildings and agricultural support infrastructure (Technical reports for EU FP7-ENV project MIA-VITA, contract number: 211393)

Quantitative assessment of the volcanic risk posed to an element requires consideration of the element’s physical vulnerability, i.e. its propensity to suffer damage. This report discusses potential damage consequences for buildings, agricultural support infrastructure and humans from the range of volcanic hazards: projectile impact, tephra fall load, pyroclastic density current, lahar and blast dynamic pressure and earthquake intensity. The information provided in this deliverable, in conjunction with agriculture vulnerability data provided by the University of Hohenheim, will inform WP2 task 2.3: Hierarchical classification of exposed elements with quantified values. Building classes are derived to describe the likely range of building stock exposed around MIA-VITA volcanoes, grouped according to their vulnerability to key volcanic hazard intensities. Using empirical and experimental data, a total of 21 new vulnerability curves are established to describe the probability of failure each of the building classes may experience with increasing hazard intensity. Measures of hazard intensity build upon the BRGM first draft of intensity scales and where appropriate, modifications to the intensity scales have been suggested. Large volcanic eruptions that impact upon the built environment are very rare and so empirical data are limited. This report therefore proposes uncertainty bounds to be used in conjunction with each of the vulnerability functions. Factors affecting the physical vulnerability of agricultural support infrastructure to volcanic hazards are discussed in detail in this report and qualitative estimates presented. Vulnerability functions that describe the human vulnerability to volcanic hazards are presented, based upon empirical assumptions, which relate the failure of a building envelope to the probability of serious injury or death. Vulnerability estimates provided in this report consider all of the currently available data regarding eruption impacts and physical vulnerabilities; data from future quantitative assessments of post-eruption damage or vulnerability testing should be incorporated to keep the estimates current.