Avalanche hazard and risk evaluation: advantages and limits of standard engineering methods and prospects for the future

Abstract

For natural hazard management in mountainous regions, design values and return periods are often used in a questionable manner. This article aims at reviewing the existing methods for predetermination and risk computations in the case of snow avalanches. After a reminder of the classical engineering methods, the recently developed statistical-dynamical approaches are introduced. They allow rigorously defining the return period as a one-to-one mapping of the runout distance and evaluating all reference scenarios corresponding to the chosen return periods. Finally, as soon as hazard consequences are quantified as a function of their magnitude, a decisional approach can be used for hazard zoning and the design of defence structures. The proposed framework is illustrated with a case study from the French avalanche database.