Mapping avalanches for safety

A researcher prepares to use lidar to scan snow depth at Arapahoe Basin in Colorado. (Photo: Riegl)

In 2014, an avalanche injured two Colorado avalanche control workers. They had been using an “avalauncher” compressed gas cannon to shoot charges into slopes that posed a serious avalanche risk to motorists below, but the charge exploded too early, in the barrel of the launcher.

The accident prompted a re-evaluation of the Colorado Department of Transportation’s avalanche control techniques.

Now, transportation officials have brought in researchers who are applying lidar to safely map snow depth in steep terrain, making avalanche control safer and more efficient for safety teams.

Jeffrey Deems, a researcher with the National Snow and Ice Data Center at the University of Colorado Boulder, and his colleagues developed the new application for lidar systems that map snow depth at high resolution. The researchers craft detailed maps of the slopes in summer, without snow, and then compare them to snow-covered slopes months later.

The researchers have been testing the technique at Colorado’s Arapahoe Basin Ski Area, where they help snow safety teams target explosives placements. The snow-depth change maps help the safety teams look for old and new snow accumulation patterns.

The data help the safety team refine their explosives targeting plans and guide them when they need to decide whether to shoot explosives into certain areas.

Also, explosives delivery tram lines for a ski area expansion are being planned and refined with the aid of the lidar-derived snow depth maps, allowing more efficient and effective tram network design. The lidar snow depth maps revealed less-obvious accumulation spots and supported a redesign of the planned tram line network.