WHAT TYPE OF SKI RUNS ARE ACCEPTABLE FOR SKIING UNDER DIFFERENT AVALANCHE HAZARD CONDITIONS? EXTRACTING KNOWLEDGE FROM HELI-SKI GUIDES

While guides in mechanized skiing operations use a well-established terrain selection process to limit their exposure to avalanche hazard and keep the residual risk at an acceptable level, the relationship between the open/closed status of runs and environmental factors is complex and has so far only received limited attention from research. Using a large data set of over 25,000 operational run list codes from a collaborating mechanized skiing operation, we applied a general linear mixed effects model to explore the relationship between acceptable skiing terrain (i.e., status open) and avalanche hazard conditions. As expected, our results show that the magnitude of this effect depends on the type of terrain that is being assessed by the guiding team. Ski runs in severe alpine terrain with steep lines through large avalanche slopes are much more susceptible to increases in avalanche hazard than more mellow terrain. However, our results also highlight the strong effects of recent skiing on the run coding and thus the importance of experiencing the conditions first-hand. Expressing these relationships numerically provides an important step towards the development of meaningful decision aids. To be presented at the International Snow Science Workshop in Innsbruck, Austria, from October 712, 2018. This version of the paper was downloaded from the website of the SFU Avalanche Research Program (SARP) at Simon Fraser University, Burnaby, Canada. For more information on our research, please visit our website at https://avalancheresearch.ca. WHAT TYPE OF SKI RUNS ARE ACCEPTABLE FOR SKIING UNDER DIFFERENT AVALANCHE HAZARD CONDITIONS? EXTRACTING KNOWLEDGE FROM HELI-SKI GUIDES Reto Sterchi* and Pascal Haegeli School of Resource and Environmental Management, Simon Fraser University, Burnaby BC, Canada ABSTRACT: While guides in mechanized skiing operations use a well-established terrain selection process to limit their exposure to avalanche hazard and keep the residual risk at an acceptable level, the relationship between the open/closed status of runs and environmental factors is complex and has so far only received limited attention from research. Using a large data set of over 25,000 operational run list codes from a collaborating mechanized skiing operation, we applied a general linear mixed effects model to explore the relationship between acceptable skiing terrain (i.e., status open) and avalanche hazard conditions. As expected, our results show that the magnitude of this effect depends on the type of terrain that is being assessed by the guiding team. Ski runs in severe alpine terrain with steep lines through large avalanche slopes are much more susceptible to increases in avalanche hazard While guides in mechanized skiing operations use a well-established terrain selection process to limit their exposure to avalanche hazard and keep the residual risk at an acceptable level, the relationship between the open/closed status of runs and environmental factors is complex and has so far only received limited attention from research. Using a large data set of over 25,000 operational run list codes from a collaborating mechanized skiing operation, we applied a general linear mixed effects model to explore the relationship between acceptable skiing terrain (i.e., status open) and avalanche hazard conditions. As expected, our results show that the magnitude of this effect depends on the type of terrain that is being assessed by the guiding team. Ski runs in severe alpine terrain with steep lines through large avalanche slopes are much more susceptible to increases in avalanche hazard than more mellow terrain. However, our results also highlight the strong effects of recent skiing on the run coding and thus the importance of experiencing the conditions first-hand. Expressing these relationships numerically provides an important step towards the development of meaningful decision aids.