Ice avalanche risk management from the Planpincieux glacier (Courmayeur - Italy)

<p>Instabilities occurring on temperate glaciers in the Alps have been the subject of several studies, which have highlighted preliminary conditions and possible precursory signs of break-off events.</p><p>Since 2013, the Planpincieux Glacier, located on the Italian side of Mont Blanc massif (Aosta Valley), has been studied to analyse the dynamics of ice collapses in a temperate glacier.</p><p>These analyses have been conducted for several years, enabling the assessment of surface kinematics on the lower glacier portion and the different instability processes at the glacier terminus. During the period of the study, especially in the summer seasons, increases in velocities of the whole right side of the glacier tongue have been recorded. This fast sliding movement is mainly induced by water flow at the bottom of the glacier.</p><p>In 2019 summer season, the increase of speed coincided with the opening of a large crevasse, which outlined a fast moving ice volume, assessed by photogrammetric techniques as 250.000 m<sup>3</sup>.</p><p>According to the risk scenarios, the collapse of this ice volume from the glacial body would have reached the valley floor, potentially affecting the access road to the Val Ferret valley.</p><p>Considering the potential risk, a civil protection plan has been deployed by the monitoring team of the Aosta Valley Autonomous Region, Fondazione Montagna sicura and CNR-IRPI.</p><p>Glacier displacements, variations in the glacier morphology and environmental variables, such as air temperature, rain and snowfall, have all been taken into account to implement the monitoring plan.</p><p>This work outlines and summarises the steps used to develop the scientific knowledge into an integrated monitoring plan and a closure plan for the Val Ferret valley.</p>

A method of deriving operation-specific ski run classes for avalanche risk management decisions in mechanized skiing

An in-depth understanding of the nature of the available terrain and its exposure to avalanche hazard is crucial for making informed risk management decisions when travelling in the backcountry. While the Avalanche Terrain Exposure Scale (ATES) is broadly used for providing recreationists with terrain information, this type of terrain classification has so far only seen limited adoption within the professional ski guiding community. We hypothesize that it is the generic nature and small number of terrain classes of ATES and its precursor systems that prevent them from offering meaningful assistance to professional decision makers. Working with two mechanized skiing operations in British Columbia, Canada, we present a new approach for deriving terrain classifications from daily terrain assessment records. We used a combination of self-organizing maps and hierarchical clustering to identify groups of ski runs that have been assessed similarly in the past and organized them into operation-specific ski run hierarchies. We then examined the nature of the emerging ski run hierarchies using comprehensive run characterizations from experienced guides. Our approach produces high-resolution ski run hierarchies that offer a more nuanced and meaningful perspective on the available skiing terrain and provide new opportunities for examining professional avalanche risk management practices and developing meaningful decision aids.

Deriving customized terrain classes for avalanche risk management in mechanized skiing operations from operational terrain assessments

An in-depth understanding of the nature of the available terrain and its exposure to avalanche hazard is crucial for making informed risk management decisions when travelling in the backcountry. While the Avalanche Terrain Exposure Scale (ATES) is broadly used for providing recreationists with terrain information, this type of terrain classification has so far only seen limited adoption within the professional ski guiding community. We hypothesize that it is the generic nature and small number of terrain classes of ATES and its precursor systems that prevent them from offering professional decision makers meaningful assistance. Working with two mechanized skiing operations in British Columbia, Canada, we present a new approach for deriving terrain classifications from daily terrain assessment records. We used a combination of self-organizing maps and hierarchical clustering to identify groups of ski runs that have been assessed similarly in the past and organized them into operation-specific terrain hierarchies. We then examined the nature of the emerging terrain hierarchies using comprehensive run characterizations from experienced guides. Our approach produces high-resolution terrain hierarchies that offer a more nuanced and meaningful perspective on the available skiing terrain and provide new opportunities for examining professional avalanche risk management practices and developing meaningful decision aids.

Characterizing the nature and variability of avalanche hazard in western Canada

The snow and avalanche climate types maritime, continental and transitional are well established and have been used extensively to characterize the general nature of avalanche hazard at a location, study inter-seasonal and large-scale spatial variabilities and provide context for the design of avalanche safety operations. While researchers and practitioners have an experience-based understanding of the avalanche hazard associated with the three climate types, no studies have described the hazard character of an avalanche climate in detail. Since the 2009/2010 winter, the consistent use of Statham et al. (2017) conceptual model of avalanche hazard in public avalanche bulletins in Canada has created a new quantitative record of avalanche hazard that offers novel opportunities for addressing this knowledge gap. We identified typical daily avalanche hazard situations using self-organizing maps (SOMs) and then calculated seasonal prevalence values of these situations. This approach produces a concise characterization that is conducive to statistical analyses, but still provides a comprehensive picture that is informative for avalanche risk management due to its link to avalanche problem types. Hazard situation prevalence values for individual seasons, elevations bands and forecast regions provide unprecedented insight into the inter-seasonal and spatial variability of avalanche hazard in western Canada.

Characterizing the nature and variability of avalanche hazard in western Canada

The snow and avalanche climate types maritime, continental and transitional are well established and have been used extensively to characterize the general nature of avalanche hazard at a location, study interseasonal and large-scale spatial variabilities and provide context for the design of avalanche safety operations. While researchers and practitioners have an experience-based understanding of the avalanche hazard associated with the three climate types, no studies have described the hazard character of an avalanche climate in detail. Since the 2009/10 winter, the consistent use of Statham et al.'s (2017) conceptual model of avalanche hazard in public avalanche bulletins in Canada created a new quantitative record of avalanche hazard that offers novel opportunities for addressing this knowledge gap. We identified typical daily avalanche hazard situations using Self Organizing Maps (SOM) and then calculated seasonal prevalence values of these situations. This approach produces a concise characterization measure that is conducive to statistical analyses, but still provides a comprehensive picture that is informative for avalanche risk management due to its link to avalanche problem types. Hazard situation prevalence values for individual seasons, elevations bands and forecast regions provide unprecedented insight into the interseasonal and spatial variability of avalanche hazard in western Canada.