GNGTS 2017 - 36° Convegno Nazionale

GNGTS 2017 S essione 1.3 197 The application of the MAGFLOWmodel for simulating the lava flow paths has represented the central part of an extensive methodology for the risk assessment at Etna (Ganci et al. , 2012). To fully evaluate likely impacts and risk that future effusive eruptions may cause to life, property and environment, it is necessary to consider the hazard, the distribution of the exposed elements at stake and the associated vulnerability. Here we assessed the risk of lava flow inundation at Etna volcano using a GIS-based methodology that integrates the hazard with the exposure of elements at stake. The hazard map by lava flow inundation at Mt. Etna (Fig. 1) was obtained combining three different kinds of information: the spatiotemporal probability for the future opening of new eruptive vents (Cappello et al. , 2013), the event probability associated with classes of expected eruptions (Cappello et al. , 2012), and the overlapping of lava flow paths simulated by the MAGFLOW model. Different elements at stake were considered, including population, hospitals, facilities, buildings, infrastructures, gas and electricity networks, railways, roads, and land use. The total exposure is given by a weighted linear combination of the four thematic layers, where weights are calculated using the Analytic Hierarchy Process (AHP). The final product of our analysis was a risk map showing the areas in which there would be the Fig. 1 - Hazard map by lava flow inundation at Mt. Etna, based on 28,908 simulations of lava flow paths starting from 4,818 different potential vents. Colors represent different hazard levels indicating a range of probability of inundation by a lava flow from a flank eruption in the next 50 years. Summit craters are masked because their activity was investigated separately (Del Negro et al. 2013).