Bayesian inference in snow avalanche simulation with r.avaflow

Author(s)
Jan-Thomas Fischer, Andreas Kofler, Andreas Huber, Wolfgang Fellin, Martin Mergili, Michael Oberguggenberger
Abstract

Simulation tools for gravitational mass flows (e.g., avalanches, debris flows) are commonly used for research and applications in hazard assessment or mitigation planning. As a basis for a transparent and reproducible decision making process, associated uncertainties need to be identified in order to quantify and eventually communicate the associated variabilities of the results. Main sources of variabilities in the simulation results are associated with parameter variations arising from observation and model uncertainties. These are connected to the measurement inaccuracies or poor process understanding and the numerical model implementation. Probabilistic approaches provide various theoretical concepts to treat these uncertainties, but their direct application is not straightforward. To provide a comprehensive tool, introducing conditional runout probabilities for the decision making process we (i) introduce a mathematical framework based on well-established Bayesian concepts, (ii) develop a work flow that couples this framework to the existing simulation tool r.avaflow, and (iii) apply the work flow to two case studies, highlighting its application potential and limitations. The presented approach allows for back, forward and predictive calculations. Back calculations are used to determine parameter distributions, identifying and mapping the model, implementation and data uncertainties. These parameter distributions serve as a base for forward and predictive calculations, embedded in the probabilistic framework. The result variability is quantified in terms of conditional probabilities with respect to the observed data and the associated simulation and data uncertainties. To communicate the result variability the conditional probabilities are visualized, allowing to identify areas with large or small result variability. The conditional probabilities are particularly interesting for predictive avalanche simulations at locations with no prior information where visualization explicitly shows the result variabilities based on parameter distributions derived through back calculations from locations with well-documented observations.

Organisation(s)
Department of Geography and Regional Research
External organisation(s)
Bundesforschungs- und Ausbildungszentrum für Wald, Naturgefahren und Landschaft (BFW), Leopold-Franzens-Universität Innsbruck, Universität für Bodenkultur Wien
Journal
Geosciences
Volume
10
No. of pages
17
DOI
https://doi.org/10.3390/geosciences10050191
Publication date
05-2020
Peer reviewed
Yes
Austrian Fields of Science 2012
105902 Natural hazards, 102009 Computer simulation, 105901 Glaciology
Keywords
ASJC Scopus subject areas
Earth and Planetary Sciences(all)
Portal url
https://ucris.univie.ac.at/portal/en/publications/bayesian-inference-in-snow-avalanche-simulation-with-ravaflow(af919878-1d9e-423b-8e78-423a181448d7).html