Morphostructural evolution and related kinematics of rockfalls in Campania (southern Italy): A case study

Abstract

On the southern slope of the Sorrentine peninsula there are many subtriangular depressions in which the main townsof the area are located; the depressions are linked to block-rotation during strike-slip fault activity and are oftenmarked by high subvertical cliffs and related rockfall phenomena with consequent damage to the underlying towns. On the basis of back analyses carried out using Hoek's method, an in- depthstudy of some of the rockfalls enabled us todefine for one of these towns the most suitable shock restitution coefficients of the detritical pyroclastic deposits present on the terraces situated at the foot of the cliffs. On the basis of the main kinematic parameters of actual rockfalls and approximately 6600 simulated rockfalls, a planning of the high-level rockfall risk valley bottoms was drawn up. The size of the high-level rockfall risk sites depends above all on the presence, number and size of the terracings wherecitrus fruit trees are cultivated. The calculation method suggested by Paronuzzi was also adopted in order to make a detailed evaluation of the role the terraces play in modifying the trajectory height, the translation velocity and the endpoint of the boulders. Although there are methodological and statistical differences between the two methods, results from both studies showed sufficient correlation, in particular concerning the trajectories' endpoints.