Stochastic dynamics of snow avalanche occurrence by superposition of Poisson processes

Paolo Perona*, Edoardo Daly, Benoit Crouzy, Amilcare Porporato

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review


We study the dynamics of systems with deterministic trajectories randomly forced by instantaneous discontinuous jumps occurring according to two different compound Poisson processes. One process, with constant frequency, causes instantaneous positive random increments, whereas the second process has a state-dependent frequency and describes negative jumps that force the system to restart from zero (renewal jumps). We obtain the probability distributions of the state variable and the magnitude and intertimes of the jumps to zero. This modelling framework is used to describe snow-depth dynamics on mountain hillsides, where the positive jumps represent snowfall events, whereas the jumps to zero describe avalanches. The probability distributions of snow depth, together with the statistics of avalanche magnitude and occurrence, are used to explain the correlation between avalanche occurrence and snowfall as a function of hydrologic, terrain slope and aspect parameters. This information is synthesized into a 'prediction entropy' function that gives the level of confidence of avalanche occurrence prediction in relation to terrain properties.

Original languageEnglish
Pages (from-to)4193-4208
Number of pages16
JournalProceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences
Issue number2148
Publication statusPublished - 8 Dec 2012


  • state-dependent Poisson process
  • stochastic dynamics
  • snow avalanches

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