A quick level methodology for the volcanic vulnerability assessment of buildings

Down the century, the volcanic eruptions have produced fatalities and economic losses. Today, almost half billion people and many conurbations (Tokyo, Mexico City, Yokohama, Seattle, Naples, etc.) are located in the proximity of very dangerous volcanoes. The volcanic risk mitigation of these areas requires a careful territorial planning together with an adequate knowledge of the behaviour of constructions under the eruption effects. The problem is very complex considering that a number of actions, such as ash fall, pyroclastic flows, flying fragments, volcanic earthquakes, lahars and tsunami, are produced by an eruptive event. Moreover, apart from the seismic case, the scientific literature relating to the structural volcanic vulnerability is poor. In this context, the paper illustrates a quick level methodology for the volcanic vulnerability assessment aimed at the identification of mitigation techniques. The 'quick' level, useful at territorial scale, is based on the identification of simple elements significant for the structures vulnerability. They are collected in a specific survey form, which adds to the information commonly required in case of the most familiar seismic vulnerability the ones specially related to all the volcano-induced phenomena. Then, the procedure furnishes a vulnerability index through the weighted combination of the vulnerability elements, according to the multi-criteria methods. The methodology proposed is a valuable tool that can be generally adopted in any kind of vulnerability investigation of buildings.