Granular Scaling Approach to Landslide Runout

A main objective in landslide research is to predict how far they will travel. Landslides are complex, and a complete understanding in principle requires accounting for numerous parameters. Here we engender a simplification by investigating the maximum landslide runout using granular laboratory experiments and a scaling analysis. We find that correctly accounting for the fall height and grain size distribution not only yields an improved correlation of normalized runout, but also quantitatively unites laboratory and field data. In particular, we find that the mobility of landslides increases with the square root of the fall height and with the skewness of the grain size distribution.