Rome: underground cavities and sinkholes. Comparison of soil data and InSar data

The city of Rome is located on a complex network of underground cavities produced by human activities (water networks, caves, catacombs, etc.), realized in more than two thousand years. The presence of underground cavities is at the origin of the collapse of the shallow soil layers causing the formation of sinkholes. In the last fifteen years, this phenomenon is increasing and may cause a danger for the population, as well as the shallow and the underground infrastructure. This phenomenon can also constitute a severe problem for the archaeological heritage and its preservation, because both the location of the underground cavities and the catacomb networks are not fully known yet. In this work, the new updated map of the known underground cavities and catacombs is used to construct the map of the cavity density in the Rome urban area. These maps, coupled with the map of the sinkhole, were compared with InSar data in order to construct a simple ranking model and then identify other areas potentially interested by cavity networks, for example, the St. Felice catacomb, in the Portuense district of Rome, is one of the largest areas of underground Christian necropolis ever discovered. PSIInSar data has been used to identify the possible site of this catacomb.