Sinkhole susceptibility, Lazio Region, central Italy

Abstract

Lazio is a region particularly affected by catastrophic sinkhole collapse. For some areas sinkholes appear to be sporadic, whilst other areas are particularly affected by sinkholes. These events can cause considerable damage when they occur in an urban area or in areas with transport networks. For several years, the Lazio Region has conducted studies on sinkholes in order to define areas prone to this phenomenon. This study involved the use of cartographic sources, historical documentation, as well as field trips, in order to construct an inventory of sinkhole cases in the region, as well as to identify sinkhole prone areas (SPAs). The inventory allowed each sinkhole case to be analysed within the geological and hydrogeological setting, as well as the surrounding vegetation and degree of urbanisation, in which it occurred. Correlations were also performed with tectonic and structural trends, and with triggering factors, such as earthquakes. Some predisposing variables to sinkhole phenomena are then selected. The application of multivariate logistic regression and geospatial analyses allows the selection of the most significant factors, as well as their optimal weights used to construct a sinkhole susceptibility map of the Latium Region at the 1:250,000 scale. The identification of the susceptibility grade of SPAs will help in the management of these areas, based on the risk level.