Interpretation and modelling of the subsidence at the archaeological site of Sybaris (Southern Italy)

Historical subsidence in the Sibari plain is made evident by the vertical stacking of three ancient towns along the Crati river. In order to investigate the evolution and the disappearance of the archaeological site and to define the causes of the settlements affecting the area since ancient times, an interdisciplinary research, about the geological, tectonical, morphological and geotechnical aspects, has been for long carried out; recent studies have focused on a recent component of the subsidence, that is also revealed by PS-INSAR monitoring data. This paper discusses the geotechnical modeling that has been developed to interpret the source of the current settlement rates. It is related to the hydraulic boundary conditions evolving in the recent past in the plain, in particular as effect of deep water extraction and of shallow water drainage by a wellpoint system working at the archeological site since the last century. The model is based on an extensive set of geotechnical profiles and laboratory data. The calculation results are compared to the recent data collected by remote sensing and allow to forecast the possible evolution of the subsidence.