On the Interpretation of Numerical Results in the Study of Rapid Landslide Run-out Phase

In the present paper, the continuum-mechanics based code RASH3D is used to evidence the influence that three factors can have on results of a numerical analysis. These are 1) the Digital Elevation Model (DEM) res-olution; 2) the morphology and substrate influence on the rheology selection; and 3) the role of the entrainment process. The Baio Dora debris flow is back-analysed to this aim. Obtained results have evidenced that a bad quality DEM can make fail all the attempts of selecting the more appropriate rheology and calibrat-ing its parameters. On the other side, the selection of a wrong rheology can give a unrealistic runout path, that is the moving mass can go as far taking a completely incorrect flowing directions. Finally, it is observed that the entrainment of channel path material can change significantly the mobility of a flow, through rapid changes of both the flow volume and rheology.