Numerical modelling of the december 1999 cervinara flow-like mass movements (southern italy)

Abstract

This paper deals with the flow-like mass movements which occurred on 15-16 December 1999 in Cervinara (Southern Italy). During this event, a huge amount of water, debris and boulders was transported from the hillslopes towards the piedmont areas causing victims, damage to buildings as well as the flooding of a large part of the urban area of the municipality. In this paper, a study is carried out with reference to the modelling of the propagation stage of the occurred phenomena which has yet to be satisfactorily addressed in current scientific literature.To this aim, the geological, geomorphological and geotechnical settings are firstly drawn up based on the available advanced data-set. Then, the event scenarios are reconstructed referring to rainfall data, information on damage and eyewitness accounts. It is high-lighted that three mountain basins were affected by three debris floods and, three hours later, a huge debris flow occurred. For all the phenomena, the propagation areas are characterised and the rheology of the propagating masses assessed; subsequently, the numerical modelling of the propagation stage is carried out. For the numerical analyses, a commercial FLO-2D code is used and different scenarios are considered with reference to different digital elevation models, in flow hydrographs and rheological parameters. The results obtained for the propagation areas match either the in-situ evidence or the eyewitness accounts of the December 1999 events.Moreover, the role of the major factors is outlined for the propagation stage of the analysed phenomena. Finally, the possibility to extend the obtained results to other similar contexts is discussed.