Item: Dan3D Model Parameters for Snow Avalanche Case Studies in Western Canada
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Title: Dan3D Model Parameters for Snow Avalanche Case Studies in Western Canada
Proceedings: International Snow Science Workshop Proceedings 2018, Innsbruck, Austria
Authors:
- Michael Conlan [ BGC Engineering Inc., Vancouver, British Columbia, Canada ]
- Jordan Aaron [ Department of Earth Sciences, ETH Zürich, Switzerland ]
- Katherine Johnston [ BGC Engineering Inc., Vancouver, British Columbia, Canada ]
- Dave Gauthier [ BGC Engineering Inc., Vancouver, British Columbia, Canada ]
- Scott McDougall [ Department of Earth, Ocean and Atmospheric Sciences, University of British Columbia, Vancouver, Canada ]
Date: 2018-10-07
Abstract: Dynamic models are an important aspect of a snow avalanche hazard assessment for planning purposes. In this research, we analyzed the ability of the three-dimensional model Dan3D to back-analyze avalanche case studies. Dan3D is a depth-averaged model that calculates flow-like motion over three-dimensional topography and was developed to simulate the motion of extremely rapid, flow-like landslides. Twenty-seven snow avalanche case studies were analyzed. Most of the cases were from British Columbia and Alberta in western Canada and one was from the state of Washington. Each avalanche case had a field-observed runout with an average return period of approximately 100 years. For each case, the Voellmy rheology was used and the two parameters, including friction and turbulence coefficients, were calibrated to determine values that best simulated the observations. Friction coefficients varied from 0.15 to 0.35. Turbulence coefficients varied from 1000 to 4000 m/s2. Models were run both with and without entrainment to assess variations in model parameters to best simulate the cases. Most cases could be modelled with reasonable runout lengths, lateral extents, and debris thicknesses. Friction and turbulence coefficients for avalanches within a certain mountain range and hence snowpack type were often similar. Although avalanche flow velocities were not available for most cases, they were within the range of those listed in other studies. Velocities were available for a case study from Norway, and modelled velocities were comparable to those observed. The results suggest that Dan3D is a capable modelling software package for performing dynamic modelling of snow avalanches.
Object ID: ISSW2018_P08.16.pdf
Language of Article: English
Presenter(s):
Keywords: dynamic model, avalanche runout, model calibration, entrainment.
Page Number(s): 783-787
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