Extreme snow avalanche runout estimates are critical in assessing avalanche risk. Statistical models estimate the extreme (100 to 300 year) runout position using the point
where the slope reaches ten degrees (β point) during descent.
Two aspects of statistical models have changed since initial development. First, digital elevations models (DEMs) are increasingly used to determine β points in place of traditional field surveys. Second, a new model (Space-Time) was developed, which determines interim (< 100 year) runout positions. This research sought to 1) determine the DEM resolution equivalent to a field survey and 2) validate the Space-Time model.
Analysis was based on terrain and vegetation observations from 94 avalanche paths in western Canada. A ten-metre resolution was found to best represent a field survey. The Space-Time model appeared to generate conservative estimates, and was most successful within the Rocky Mountains. Limitations arose from small datasets and uncertainty surrounding vegetation analysis.