Snow avalanches regularly damage infrastructure and block transportation corridors in mountainous regions in Alaska, impeding access to natural resources and critical public services. In response to imminent mandatory retirement of the avalanche mitigation artillery program, avalanche safety programs across the country are now challenged with finding new solutions to mitigate snow avalanche hazards. Remote Avalanche Control Systems (RACS) offer a slope-based alternative avalanche mitigation option, but system deployments are most successful when design and operational decision making is supported by local snow distribution data and accurate predictions of avalanche dynamics. In a collaborative project with Alaska Railroad Corporation (ARRC), we assessed the proposed placement of RACS towers in a prominent avalanche path (“Door 4”) along the railroad west of Whittier, Alaska. The project consisted of near-peak snow height aerial lidar surveys for winters 2020/2021 and 2021/2022 and avalanche simulations using Rapid Mass Movement Simulations (RAMMS) to investigate the destructive potential of avalanches released at the proposed RACS locations, and to assess the potential damage (impact pressure of moving snow from above) at the proposed RACS tower sites. Results from the lidar campaigns show a consistent snow distribution pattern in the Door 4 avalanche release areas, with highly variable snow depths from 0 m to 10 m. Most of the initially proposed tower locations target the deeper pockets of snow, suggesting ideal placement. However, simulated avalanche impact pressures for both wet and dry avalanches, from empirically derived and modeled potential release areas, led to change in the locations of some of the proposed RACS tower sites. This study demonstrates the importance of identifying patterns in snow distribution and simulating avalanche dynamics to strategize RACS tower placements prior to installation to optimize mitigation efforts and minimize damage to towers.
Wikstrom Jones, K. Wolken, G.J., McKee, M., Bartelt, P., Bühler, Y., Christen, M.. 2023. Using snow remote sensing and avalanche simulations to inform the placement of remote avalanche control systems. International Snow Science Workshop Proceedings. 1155 – 1162. http://arc.lib.montana.edu/snow-science/item/3026.