Natural sinkholes in Umbria region (Central Italy): a regional-scale inventory and susceptibility assessment

Francesco Venti¹, Giancarlo Ciotoli², Sergio Madonna³ & Stefania Nisio^1
1ISPRA – Italian Institute for Environmental Protection and Research, Geological Survey of Italy, Via Brancati 48, 00144 Rome, Italy.
²CNR – National Research Council of Italy, Institute of Environmental Geology and Geoengineering (IGAG), Rome, Italy.
³University of Tuscia, Viterbo, Italy.
Corresponding author e-mail: francesco.venti@isprambiente.it

This study presents the first regional-scale assessment of natural sinkholes in the Umbria region (central Italy), aimed at improving the understanding of their distribution, genesis, and susceptibility. Starting from the ISPRA sinkhole database, the existing inventory was updated and significantly expanded through the integration of geological, hydrogeological, and geomorphological data, which also supported a genetic classification of the identified sinkholes. A comprehensive set of geothematic layers representing potential predisposing factors was compiled and analysed within a GIS framework. These datasets were used to perform geostatistical analyses and to develop susceptibility models for natural sinkholes. The resulting susceptibility maps, differentiated according to sinkhole typology, provide a spatially explicit representation of areas potentially prone to sinkhole occurrence. The outcomes contribute to improving the regional knowledge of sinkhole processes and offer a methodological framework to support hazard assessment, land-use planning, and risk mitigation strategies.

natural sinkholes, Umbria, susceptibility, karst processes, piping sinkhole, karst phenomena.