111446
20180317092908.0
7129
DAR
000231538700004
ISI
ARTICLE
Monte Carlo calibration of avalanches described as Coulomb fluid flows
2005
2005
Journal Articles
The idea that snow avalanches might behave as granular flows, and thus be described as Coulomb fluid flows, came up very early in the scientific study of avalanches, but it is not until recently that field evidence has been provided that demonstrates the reliability of this idea. This paper aims to specify the bulk frictional behaviour of snow avalanches by seeking a universal friction law. Since the bulk friction coefficient cannot be measured directly in the field, the friction coefficient must be calibrated by adjusting the model outputs to closely match the recorded data. Field data are readily available but are of poor quality and accuracy. We used Bayesian inference techniques to specify the model uncertainty relative to data uncertainty and to robustly and efficiently solve the inverse problem. A sample of 173 events taken from seven paths in the French Alps was used. The first analysis showed that the friction coefficient behaved as a random variable with a smooth and bell-shaped empirical distribution function. Evidence was provided that the friction coefficient varied with the avalanche volume, but any attempt to adjust a one-to-one relationship relating friction to volume produced residual errors that could be as large as three times the maximum uncertainty of field data. A tentative universal friction law is proposed: the friction coefficient is a random variable, the distribution of which can be approximated by a normal distribution with a volume-dependent mean.
monte carlo calibration
avalanche
fluid flow
Ancey, Christophe
148669
240366
1529-1550
1832
Philosophical Transactions: A Mathematical, Physical & Engineering Sciences, The Royal Society
363
n/a
308485
n/a
http://infoscience.epfl.ch/record/111446/files/Monte%20carlo%20calibration...%2C%20phil.trans.r.soc.A%2C%202005%2C%20363%2C%20Ancey%20LHE.pdf
oai:infoscience.tind.io:111446
ENAC
article
LHE
252029
U10257
106556
LHE-ARTICLE-2005-007
11/LHE
EPFL
PUBLISHED
REVIEWED
ARTICLE