Articles | Volume 17, issue 9
Nat. Hazards Earth Syst. Sci., 17, 1487–1492, 2017
Nat. Hazards Earth Syst. Sci., 17, 1487–1492, 2017

Brief communication 08 Sep 2017

Brief communication | 08 Sep 2017

Brief communication: Accuracy of the fallen blocks volume-frequency law

Valerio De Biagi Valerio De Biagi
  • Department of Structural, Geotechnical and Building Engineering, Politecnico di Torino, Turin, Italy

Abstract. De Biagi et al. (2017) have proposed a procedure for building a fallen block volume-frequency law for rockfall phenomenon. The input data are from both the recording of rockfall events and from the survey of fallen block volumes. The epistemic and aleatoric uncertainties present in the approach affect the value of the parameters of the law. It is shown how to quantify the errors due to missed events, to an observation period of finite duration and to a limited set of measured blocks. At the end, the procedure outputs corrective parameters to compute a design volume for rockfall analysis and engineering calculations.

Short summary
Some interesting questions were raised during the review process of a recent paper on a method for obtaining a fallen-block volume-frequency law, e.g. related to the minimum number of observations needed for obtaining the law. This brief communication addresses this point. In detail, the errors due to a reduced number of recorded fallen-block events and to the consistency of the measured blocks at the foot of the cliff are computed. This is useful for design purposes.
Final-revised paper