Geomorphological analysis applied to rock falls in italy: the case of the san venanzio gorges (aterno river, abruzzo, italy)

Abstract

Among the types of instability, which vary in terms of typology, evolution and dimension, rock falls represent a constant hazard for structures, buildings and the population, because of their extreme speed. Rock falls in central Italy (Abruzzo Region) occur within the chain area, at the junction between the chain area and the piedmont and between piedmont hills and coastal sectors with wide coastal cliffs. This work focuses on the multidisciplinary analysis of rock falls affecting fault homocline ridges and, particularly, on the case of the San Venzanzio gorges (Aterno river) well known for rock falls particularly after the 2009 L’Aquila eartquake. The gorges are located along the Aterno river within the central Apennines, between L’Aquila and Sulmona, in a geological and geomorphological context typical of the Apennines chain. The analysis is based on 1:5.000-1.10.000 field geological and geomorphological mapping integrated with reported events analysis,photogeological analysis, laser scanning and geomechanical investigations. This approach is considered vital for a correct investigation of rock fall hazard and susceptibility, particularly on large slopes where topographical, geological, tectonic, geomechanical and geomorphological variation control rock fall development. In these cases, only a complete geological, morphostructural and geomechanical data set allows to achieve effective results when applying deterministic and probabilistic methods for rock falls investigation.