Topography-based modeling of large rockfalls and application to hazard assessment

Rockfalls are among the most important natural hazards in mountainous regions. Similarly to earthquakes and wild-fires, their sizes follow a power-law distribution covering an enormous range of sizes. In this paper, the presumably first modeling approach that explains this power-law distribution quantitatively is presented. Applied to the European Alps, the Himalayas and the Rocky Mountains, the model suggests that a power-law exponent of 1.35 with respect to the detached volume is a universal property of rockfalls. Beyond reproducing and explaining existing statistical data, the model allows an estimate on size and frequency of the largest possible rockfalls in a region, which cannot be derived from available rockfall inventories so far. Citation: Hergarten, S. (2012), Topography-based modeling of large rockfalls and application to hazard assessment, Geophys. Res. Lett., 39, L13402, doi:10.1029/2012GL052090.