Lava-flow hazard with optimized non-uniform grid of vents

The aim of the study is to assess the sensitivity to vents (in terms of number and distribution) of sectors affected by lava flows and of hazard values at Mount Etna. The proposed methodology relies on the application of the Cellular Automata model SCIARA, and on the adoption of an optimization algorithm for progressively integrating an initial uniform distribution of 1006 vents (1-km spaced) with 500 additional sources. Vents have iteratively been added, at steps of 50. through spatial simulated annealing, using slope roughness as weigh function. For each vent, 41 types of simulations have been executed to take into proper account the potential behaviour of the volcano, based on historical records. The performed simulations have been further processed to derive lava-flow hazard, by assigning each simulation: i) a spatial likelihood of vent opening, ii) a magnitude probability, depending on the type of eruption, and hi) a temporal probability of source activation, based on historical occurrences in the past 400 years. First results are discussed, and the influence of the number and distribution of additional vents is preliminarily investigated.