An approach to assess the detachment propensity of rockfall source areas: the Susceptibility Index to Failure (SIF)

This paper proposes a practical approach to assess the susceptibility of rock slopes to produce rockfalls. Once identified the potential release areas, a rockfall Susceptibility Index to Failure (SIF) can be assigned to distinguish among prone areas with detachment propensity from 0 (null probability) to 1 (maximum probability). This index can be defined according to the presence and intensity of several causative factors, which were identified and scored on the basis of the scale of interest and the environment considered. Specifically, the small and the detailed scales and the mountain and coastal-marine environments were considered. An application example is presented to illustrate the validity of the proposed approach.