Sinkholes in volcanic areas of Central and Southern Italy: inventory update and occurrence of natural and anthropogenic processes

Stefania Nisio¹, Sergio Madonna², Francesco Gentili² & Livio Ruggiero^3
1ISPRA Dipartimento per il Servizio Geologico d'Italia – Via Vitaliano Brancati 48, 00144 Roma (Italy).
²Università degli Studi della Tuscia - Via San Camillo de Lellis, 01100 Viterbo (Italy).
³CNR Piazzale Aldo Moro, Roma (Italy).
Corresponding author e-mail: sermad@unitus.it

Volcanic plateaus in central and southern Italy, particularly in Lazio and Campania, have long been considered suitable for urban, industrial, and infrastructural developments due to their apparent stability and generally favourable geomorphological and geotechnical characteristics. However, both natural and anthropogenic sinkholes occur widely in these settings and are still largely underestimated in hazard assessment and land-use planning, as sinkhole processes are commonly associated only with karst and pseudokarst environments. Data from the Italian Sinkhole Database (ISPRA), updated within the framework of the Geosciences-IR project, highlight the significant occurrence of sinkholes in volcanic areas, including sectors hosting strategic infrastructure. Natural sinkholes are mainly related to groundwater-level fluctuations, gas emissions, structural discontinuities, and the presence of karstifiable travertine layers interbedded within pyroclastic successions. Anthropogenic sinkholes are also widespread, especially in urban and peri-urban areas, where they are associated with long-standing underground networks such as cuniculi, aqueducts, catacombs, and quarries, often reactivated or exacerbated by hydraulic failures and intense rainfall events. The updated inventory emphasises the need to consider sinkhole hazard as a relevant geological risk also in volcanic terrains and to incorporate dedicated mitigation strategies into land-use planning and infrastructure management.

sinkhole, volcanic areas, anthropogenic cavities, morphological convergence, hazard assessment.