Influence of Tectonics and Morphometric Features on the Landslide Distribution: A Case Study from the Mesima Basin (Calabria, South Italy)

Identifying the instability areas provides useful information about the recognition of the vulnerable zones and, thus, helps to potentially decrease the harm to the infrastructure and the hazard conditions in inhabited areas. In this regard, morphometric parameters and tectonic setting are widely employed in mapping, modelling and understanding of instability processes. The present study is aimed to analyse the combined effects of slope morphometry (slope gradient, slope curvature, local relief), of lithology, of drainage density and of tectonic setting on the distribution of landslides. The study area is located in the Mesima Basin that lies in the central part of the Calabria region (southern Italy). The morphometric analysis was carried out by geographic information system (GIS) techniques, whereas the geomorphic attributes were computed by a digital elevation model (DEM). The recognized landslides and faults were digitized and stored in a GIS geo-database that allowed the construction of relative density maps. A total of 1 991 landslides and 231 tectonic lineaments were recognized and mapped. The distribution of the collected data suggests that the occurrence of landslides is not random. Indeed, the research highlights as the lithology, the fault density, the slope gradient and the local relief play an important role in determining the landslide occurrence. The used approach is aimed to reinforce the knowledge about the validity of the application of morphometric analysis to the landslide susceptibility. The Mesima Basin is a poorly studied area of the Calabria from a geomorphological viewpoint. Indeed, previous researches focused mainly on geological and on tectonic aspects, as well as on instability phenomena in the Mesima surroundings. Thus, this paper takes a step forward with respect to previous studies because it augments the knowledge about the relationship between faults, morphometric features and the occurrence of landslide.