ABSTRACT
The support of a GIS could be useful for the management of technological hazard triggered by the ash fallout; in this context, the volcanic ash emission in the atmosphere could be considered as a geoevent, this term identifies a graphical representation of the evolution of the scenario (in this case the plume and the associated fallout) by means of its geographical coordinates. A geoevent can be considered as a dynamic event, in some cases, its graphical representation can provide a valid support to risk managers. It is worth noting that the risk management activities could be difficult if the territory is characterized by the presence of a great urbanization, of numerous chemical industries and of a complex network of lifelines.
