Landslide Hazard and Risk in the Campi Flegrei Caldera, Italy

This chapter deals with the main characteristics of the mass movements affecting the slopes of the Campi Flegrei Volcanic Field. To this aim, giving due credit to previous works, an overview of the Phlegraean landslides is presented, taking into account other ongoing researches. The prevailing landslide types depend upon the lithological characteristics of the rocks involved: slides and flows dominate in the loose pyroclastic deposits, while falls and topples characterise the slopes where tuffs and lavas crop out. All the Phlegraean landslides show a moderate mobility, with a maximum runout distance lower than 350 m, and a mean angle of reach equal to 39°. More than 15% of the whole territory of the six Phlegraean towns is prone to landslide hazard, though the distribution of at-risk areas among the six towns is uneven (e.g., Monte di Procida, 31.7%; Quarto, 5%). Due to the intense urbanisation of the area, such a hazard results in a quite high risk. In recent years, a number of structural countermeasures, including low-impact soil bioengineering techniques, have been introduced as to mitigate the landslide risk in the Neapolitan-Phlegraean area. However, a paradigm shift is strongly needed, due in part to the persistent economic crisis, which should induce to emphasise the importance of non-structural preventive solutions, among which the improvement of the urban communities’ societal resilience is of paramount importance.