L'area ad elevata franosità di Corniglio (Parma): evidenze di deformazioni gravitative profonde e studio degli spostamenti superficiali nel periodo 1976-2008

We present the results of the study and the ground displacement measurements of the Corniglio landslide located close to Corniglio (PR). Geomorphologic survey and photogeologic interpretation of multitemporal aerial photographs and a Quickbird satellite imagery (from 1976 to 2005) were carried out in order to analyse both the geologic features of the landslide and the state of activity. Metric use of multitemporal remote sensing imagery allowed us to measure and then to interpolate ground displacement of homologous targets, so achieving multitemporal maps of displacements. We obtained a model where the occurrence of rigid behaviour lithotypes (Mt. Caio flysch and “Arenarie del Bratica” formations) overlying plastic low-shear strength lithotypes (“Melange di Lago” and “Argille e Calcari” formations) represents a critical setting for the stability of the area. East-west trending lineaments characterising the fragile structural framework of the study area are also involved into landsliding processes. So we suggest the Corniglio landslide is part of a larger Deep-Seated Slope Gravitational Deformation, involving the hills among the Bratica and Parma rivers and the same Corniglio landslide.