Cj. Keylock et M. Barbolini, Snow avalanche impact pressure - vulnerability relations for use in risk assessment, CAN GEOTECH, 38(2), 2001, pp. 227-238
Use of formal risk analysis to assess avalanche danger is currently limited
by a lack of knowledge of how avalanche impact pressures damage structures
and cause fatalities. That is, the vulnerability component of risk is poor
ly specified. In this paper we outline a method for deriving vulnerability
values as a function of position downslope for a range of avalanche sizes.
The method is based on the weighted average of vulnerability and uses an av
alanche-dynamics model embedded within a statistical framework. The models
seem to behave in a consistent manner. By allowing avalanche size and stopp
ing position to vary and calculating vulnerability as a function of distanc
e from the stopping position, vulnerability values are less approximate tha
n the assumption of a constant vulnerability value for each individual size
. When the assumptions underlying the impact pressure - vulnerability relat
ion are perturbed, the results seem to be robust. The method outlined here
should provide a way for avalanche experts to reformulate danger zones base
d on return period and impact pressure so that they are set within a risk f
ramework.