• chemical plant
• equipment vulnerability
• GIS
• natural-technological scenario (Na-Tech)
• Vulnerability map

Natural events can be the indirect cause of technological accidents with severe consequences for human beings and the environment. In the literature, these events are also known as Na-Techs (i.e. technological events triggered by natural causes). Na-Techs may damage structures, infrastructures, chemical industries, utility distribution networks (lifelines), etc. The overall magnitude could be much greater than that of the natural event. A great concern is also related to other aspects, such as the potential overloading of the emergency response and/or the unavailability of essential utilities (water, electricity, etc.).
This thesis aimed at the investigation of volcanic Na-Tech scenario and the definition of vulnerability models, which allow implementing the Quantitative Risk Assessment procedure to include volcanic Na-Tech and identifying malfunctions in wastewater treatment. The main focus was on a particular volcanic hazard, i.e. volcanic ash fallout, whose impact covers large areas, in same case a continental dimension.
The results of this study permitted also the definition of semi-automatic procedures for the production of the vulnerability maps by using a GIS (Geographical Information System) software.
After the development of vulnerability models of some industrial equipment, it was possible to investigate a case-study, which was the surrounding of Mt. Etna (Italy).