Lithological, geomorphological and tectonic control on landslide processes in Southern Italy: insights from a regional inventory and metrics of landscape evolution

Abstract

The landscape of Southern Italy is widely affected by landslide processes of different types, sizes and ages, which locally play an important role in the landscape evolution, slope evolution, and sediment mobility of different sectors of the belt. We perform a statistical analysis of a landslide inventory map that covers the administrative territory of Basilicata, southern Italy, aimed at the investigation of the interplay between landslide distribution and lithological and geomorphological factors. Statistical analysis of the landslide inventory map and the comparison with geothematic maps and landscape metrics provide new insights into both the main predisposing factors of landslide processes and the role of long-term morphotectonic evolution on the landslide pattern. Our results indicate a total landslide density of about 7% across the study area, with a predominance of slow-moving landslides and a highly clustered, non-random spatial distribution. Landslide-dominated landscapes, characterized by the superimposition of large deep-seated and smaller, shallow landslides, are also widespread. Analysis of the relationships between landslide patterns and metrics of landscape evolution indicates that lithological and topographic characteristics alone cannot account for the preferential occurrence of landslides in these morphotectonic domains, pointing instead to a significant role of tectonically induced landscape disequilibrium in controlling landslide distribution.