Sinkholes in Italy: first results on the inventory and analysis

The Italian Geological Survey ( APAT) carried out field surveys and analysis of collapse phenomena (sinkholes) in Italy. The main goal of the project is to collect geological, geomorphological, geochemical and hydrogeological data about the sinkhole-prone areas in Italy in order to develop a spatial database of the characteristics of each phenomenon. The preliminary results of this study provide information on the distribution, geological setting, and monitoring and remediation actions associated with these natural collapses in Italy. Many Italian regions are affected by these natural disasters. Some of them are caused by karst collapses or anthropic activity. However, some occur in areas characterized by buried carbonate bedrock (up to 190 m), as well as by peculiar geological-structural and geochemical scenarios. In these areas it is not reasonable to ascribe the formation mechanism to karst activity. Instead, these types of cavities quickly develop in terrains with a variable granulometry, often in connection with upwelling fluids. In this work some natural specific cases have been studied in order to define the relationships between the geology (regional tectonic elements, mineral spring waters and strong gas vents) and the genesis of the sinkholes. A first attempt of sinkhole classification is also presented.