Le cavità antropiche presenti nel sottosuolo di Bolsena

Abstract

The old town of Bolsena hosts many underground cavities located mainly north of the area bonded by Corso Cavour - Corso Vittorio Emanuele - Via 4 Novembre. The cavities develop within the Vulsini volcanic units outcropping in the north-eastern rim of the caldera. This network of hypogea was built, probably starting from the Etruscan age for a series of activities as the extraction of building materials, hydraulic tunnels, necropolis, cellars, cisterns, etc. A GIS project was created using the open-source software QGIS to manage all the data collected during the detailed topographic and geotechnical survey of the cavities, in order to compare them with the sinking phenomena that have occurred in the past or that may occur in the future. The distribution of the detected cavities suggest that there cold be additional cavities hidden under the urban fabric in the central- northern sector of the old town in which it was not possible to access or which memory has been lost.