Statistical runout modeling of snow avalanches using GIS in Glacier National Park, Canada

Using models to estimate snow avalanche runout distance is useful for areas where there is a lack of historical avalanche observations and no obvious physical signs of avalanche activity. Along roadways, details of avalanche runout are often recorded; however, in Canada, backcountry areas typically used by recreationists may not have a recorded history of avalanche activity or runout distances. Knowledge of predicted runout extents mapped in Geographic Information Systems (GIS) has the potential to inform backcountry users on route selection and decision making pertaining to slopes for skiing, snowboarding, ice climbing and snowmobiling. The Rogers Pass area in Glacier National Park, British Columbia, Canada provides an ideal location for studying well documented avalanche paths that impact the Trans Canada Highway, as well as representing a backcountry area that is a popular ski touring destination in Canada. A statistical approach using the alpha–beta runout model, first developed in Norway, has been adapted for use in Rogers Pass. Topographic parameters from well-known avalanche paths along the Trans Canada Highway corridor, with a historical record of over 40 years, have been extracted with GIS and used to calibrate the alpha–beta runout model. This model is then applied to an avalanche path in the Glacier National Park backcountry. A high resolution Digital Elevation Model (DEM) was created for the study area using digital stereo photogrammetry. A comparison of model calculations using the higher resolution dataset and a lower resolution dataset did not reveal any significant difference between the model parameters.