Geotechnologies for sinkhole risk mitigation in coastal karst settings: insights from Maratea (Basilicata, Southern Italy)

Federica Ferrigno¹, Francesco Traversa¹, Giuseppe Delmonaco¹, Roberto Pompili¹, Vincenzo Allocca² & Giacomo Russo^2
1ISPRA - Institute for Environmental Protection and Research, Department for the Geological Survey.
²Department of Earth Sciences, Environment and Resources, University of Naples Federico II.
Corresponding author e-mail: federica.ferrigno@isprambiente.it

Natural sinkholes are among the most critical geological hazards in karst terrains, where surface collapses can occur suddenly and affect infrastructure, cultural heritage, and human safety. Coastal environments are particularly vulnerable due to the combined effect of karst dissolution, structural discontinuities, and wave-induced erosion. This study focuses on the coastal sector of Maratea (Basilicata, Southern Italy), the only Tyrrhenian outlet of the region, which extends over ~32 km and hosts several sinkholes and marine caves at different evolutionary stages. A multidisciplinary methodology was applied, combining hydrogeological, geological and geomechanical measurements with field surveys, and drone-based photogrammetry. Sinkhole sites were documented through high-resolution orthophotos and 3D models, while kinematic analysis supported the identification of instability mechanisms (planar sliding, wedge sliding, direct toppling). The integration of speleological and GIS data confirmed the strong relationship between marine caves and sinkhole collapse. Results highlight the role of tectonic discontinuities, karst processes, and marine erosion in triggering cliff failures, proposing a methodological framework useful for hazard assessment and coastal risk mitigation.

sinkholes, coastal karst, rock mass discontinuities, kinematic analysis, marine caves, UAV photogrammetry.