Collapse sinkholes in Campania (southern Italy): predisposing factors, genetic hypothesis and susceptibility

This paper provides for the first time a solid data base on sinkholes of the carbonate massifs of the Southern Apennine chain. It also outlines that sinkhole occurrence is controlled by the concomitance of the following main factors: presence of highly jointed limestone, presence of mineral springs and high seismicity conditions. A possible model for their geomorphologic evolution is also proposed. The main hope is that this work will be useful for subsequent studies aiming at defining the main hazard and risk situation in Campania. Unfortunately, many of the studied sinkholes are located in the vicinity of urban areas or near to important infrastructures but their presence was not taken into account neither for the construction of underground works nor for territorial planning. At the present it can be stated that some sectors of the southern Apennine carbonate massifs are more susceptible to sinkhole formations, even more considering the high seismicity of the area and the possibility of the occurrence of catastrophic events in concomitance of strong earthquakes. In these areas the territorial planning and seismic zonation studies have to take into account the real possibility of the occurrence of abrupt collapse phenomena and forecast adequate and detailed geological and geotechnical surveys.