Estimating Landslide Volumes Using LS-rapid Model -The 2000 Stože Landslide in NW Slovenia

Potential landslides may after activation present a debris-flow source, and hence reliable potential landslide volume estimation is a significant factor when assessing regional debris-flow hazard. A 3D landslide simulation model LS-Rapid was applied to analyze the triggering phase of the rainfall-induced 2000 Stože Landslide in NW Slovenia, Europe. It was triggered on a steep Stože slope in November 2000. The destabilized mass moved and fluidized, and flowed as a dry debris flow to a torrent channel; due to inflow of rainfall and flow from the Mangartski potok torrent, after 35h it turned into a wet debris flow that reached the village of Log pod Mangartom, several kilometers away from the landslide source area. The known volume of the 2000 Stože Landslide was estimated using LS-Rapid simulation results. In addition, other parameters of the 2000 Stože Landslide (e.g. triggering factors, landslide source area, landslide contour, volume and depth, super elevation on its path, deposition area) were used to validate the LS-Rapid modeling results. Based on this case study, limiting boundaries for key soil parameters in the LS-Rapid model were proposed to help with the LS-Rapid model data preparation, when the model is applied for potential landslides where no model validation and calibration is possible, and when no ring-shear apparatus is at hand to estimate soil parameters.