3D numerical modelling of submerged and coastal landslide propagation

The analysis of the propagation phase plays a fundamental role in the assessment and forecasting of risks related to the occurrence of submerged and coastal landslides. At present there are few numerical models able to simulate the propagation of such a type of events. This paper presents fully 3D models and approaches developed by the authors and suitable for the simulation of both completely subaqueous landslides and combined subaerial-submerged ones (i.e. coastal landslides with a subaerial source which propagate underwater). A Cellular Automata model is described which has been specifically designed for combined subaerial-submerged landslides. Moreover, a new approach able to simulate submerged mass movements using commercial 3D software, originally developed for subaerial landslides, is presented. Calibration and validation of these models upon a real and well constrained coastal debris flow at Lake Albano (Rome, Italy) is also presented.