Estimating extreme avalanche runout for the Columbia Mountains and Fernie area Rocky Mountains of British Columbia, Canada

Abstract

Extreme snow avalanche runout is typically estimated using a combination of historical and vegetation records as well as statistical and dynamic models. The two classes of statistical models (α–β and runout ratio) are based on estimating runout distance past the β-point, which is typically defined as the point where the avalanche slope incline first decreases to 10°. The parameters for these models vary from mountain range to mountain range. In Canada, α–β and runout ratio parameters have been published for the combined Rocky and Purcell Mountains and for the British Columbia Coast Mountains. Despite active development, no suitable tall avalanche path model parameters have been published for the Columbia Mountains or for the Lizard Range area around Fernie, B.C. Using a dataset of 65 avalanche paths, statistical model parameters have been derived for these regions.