Natural sinkholes of Abruzzo (central Italy): expansion of ISPRA National Database and susceptibility analysis

Abstract

The term sinkhole refers to sudden ground subsidence caused by natural or anthropogenic factors and represents a locally significant geological hazard. In Italy, natural sinkholes are included in ISPRA’s National Sinkhole Database, mainly in plains, coastal zones, and tectonic intermontane basins. The Abruzzo is among the most susceptible areas due to its geological complexity and seismic activity, with approximately 100 previously cataloged sinkholes, many linked to major earthquakes in the Upper Aterno River Valley, the Fucino basin, and the Sulmona basin. This study aims to expand the database and improve knowledge of sinkhole occurrence in Abruzzo. A GIS-based geodatabase was developed to organize and analyse data from the literature, topographic maps, and satellite imagery, leading to the identification of approximately 720 sinkholes. Field surveys were systematically conducted to validate sinkholes located in lowland areas. Morphometric and geological analyses indicate that most features are cover-collapse sinkholes in flat areas, while solution sinkholes related to carbonate dissolution are also widespread. A probabilistic susceptibility analysis was performed using the Maximum Entropy (MaxEnt) algorithm, highlighting slope and lithology as the main predisposing factors influencing sinkhole formation in the region.