07 Feb 2023
 | 07 Feb 2023
Status: this preprint is open for discussion.

Accounting for the effect of forest and fragmentation in probabilistic rockfall hazard

Camilla Lanfranconi, Paolo Frattini, Gianluca Sala, Davide Bertolo, Juanjuan Sun, and Giovanni Battista Crosta

Abstract. The presence of trees along the slope and block fragmentation at impact strongly affect rockfall dynamics, and hazard as a consequence. However, these phenomena are rarely simulated explicitly in rockfall studies. We performed rockfall simulations by using the 3D rockfall simulator Hy-Stone, modelling both the presence of trees and fragmentation through specific algorithms implemented in the code. By comparing these simulations with a more classical approach that attempt to account implicitly for such phenomena in the model parameters, and by using a new probabilistic rockfall hazard analysis (PRHA) method, we were able to quantify the impact of these phenomena on the design of countermeasures and on hazard.

We demonstrate that hazard changes significantly when accounting explicitly for these phenomena, and that a classical implicit approach usually overestimates both the hazard level and the 95th percentile of kinetic energy, leading to an oversizing of mitigation measures.

Camilla Lanfranconi et al.

Status: open (until 14 Apr 2023)

Comment types: AC – author | RC – referee | CC – community | EC – editor | CEC – chief editor | : Report abuse
  • RC1: 'Comment on egusphere-2022-1521', Anonymous Referee #1, 06 Mar 2023 reply
  • RC2: 'Comment on egusphere-2022-1521', Anonymous Referee #2, 25 Mar 2023 reply

Camilla Lanfranconi et al.

Camilla Lanfranconi et al.


Total article views: 198 (including HTML, PDF, and XML)
HTML PDF XML Total Supplement BibTeX EndNote
141 47 10 198 23 2 2
  • HTML: 141
  • PDF: 47
  • XML: 10
  • Total: 198
  • Supplement: 23
  • BibTeX: 2
  • EndNote: 2
Views and downloads (calculated since 07 Feb 2023)
Cumulative views and downloads (calculated since 07 Feb 2023)

Viewed (geographical distribution)

Total article views: 194 (including HTML, PDF, and XML) Thereof 194 with geography defined and 0 with unknown origin.
Country # Views %
  • 1
Latest update: 31 Mar 2023
Short summary
This paper presents a study on rockfall dynamics and hazard, examining the impact of the presence of trees along slope and block fragmentation. We compared rockfall simulations that explicitly model the presence of trees and fragmentation with a classical approach that account for these phenomena in model parameters. Both the hazard and the kinetic energy change. We also used a non-parametric probabilistic rockfall hazard analysis method for hazard mapping.