Item: BRITISH COLUMBIA MINISTRY OF TRANSPORTATION AND INFRASTRUCTURE PROVINCIAL AVALANCHE HAZARD INDEX
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Title: BRITISH COLUMBIA MINISTRY OF TRANSPORTATION AND INFRASTRUCTURE PROVINCIAL AVALANCHE HAZARD INDEX
Proceedings: International Snow Science Workshop Proceedings 2023, Bend, Oregon
Authors:
- Brian Gould [ Alpine Solutions Avalanche Services, Canada ]
- Scott Thumlert [ Alpine Solutions Avalanche Services, Canada ]
- Eirik Sharp [ Alpine Solutions Avalanche Services, Canada ]
- Cam Campbell [ Alpine Solutions Avalanche Services, Canada ]
- Dorian Schjelderup [ Alpine Solutions Avalanche Services, Canada ]
- Lea Green [ Alpine Solutions Avalanche Services, Canada ]
Date: 2023-10-08
Abstract: This paper presents work completed to quantify and visualize snow avalanche hazard for the entire provincial highway network as managed by the British Columbia Ministry of Transportation and Infrastructure (the Ministry) in Canada. The project used the Avalanche Hazard Index (Schaerer, 1989) to describe highway avalanche hazard numerically and developed a geospatial tool that can be used for decision-making. The tool allows the identification of avalanche program areas, highway corridors, and specific paths where improved risk mitigation measures would be most beneficial and can support prioritizing avalanche risk mitigation investments. The 62 avalanche hazard forecast areas affecting provincial highways are well known to the Ministry, however changes to avalanche path characteristics, implementation of new avalanche mitigation technologies, changes to traffic volumes, and changing environmental conditions over the past few decades has provided motivation for this new assessment. In order to complete the AHI analysis, Ministry data for relevant highway corridors and avalanche paths were collected from a variety of sources. These included: • Historical avalanche occurrence records as maintained by the Ministry - 173,869 avalanches. • British Columbia digital road atlas – data for 196 highway corridor sections (e.g. speed limits, number of lanes). • Ministry Traffic Data Program database – traffic volumes. • Ministry digital avalanche path mapping – widths and locations for 1546 paths. • Ministry avalanche path atlases – general data for the paths. • Historical aerial photographs – analysis of hundreds of aerial photographs dating back to 1937 was used to refine avalanche path dimensions. These data were then adjusted based on interviews with key Ministry personnel combined with expert judgment. The resulting dataset was stored in a geodatabase and analyzed with an automated algorithm to calculate AHI values following the commonly accepted methodology outlined in Schaerer (1989). Data-driven methods were employed for the AHI input parameters wherever reasonable. The calculated AHI values are hosted on a web-based Geographical Information System (GIS) dashboard that promotes user-friendly interaction and scenario testing with the data. The interactive dashboards allow testing of various mitigation scenarios (e.g. how does the addition of an avalanche deflection berm to an identified path affect the AHI value for an avalanche area or highway corridor?). Relative differences in AHI values and subsequent amount and type of mitigation can be compared between different highway corridors.
Object ID: ISSW2023_P2.37.pdf
Language of Article: English
Presenter(s): Brian Gould
Keywords: British Columbia, Ministry of Transportation and Infrastructure, avalanche hazard index, transportation corridor risk, risk planning tool, AHI
Page Number(s): 869 - 876
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