Abstract
Two-dimensional avalanche simulation software operating in three-dimensional terrainis widely used for hazard zoning and engineering to predict runout distances andimpact pressures of snow avalanche events. Mountain forests are an effective biologicalprotection measure; however, the protective capacity of forests to decelerate or even to stop avalanches that start within forested areas or directly above the treeline isseldom considered in this context. In particular, runout distances of small- to medium-scale avalanches are strongly influenced by the structural conditions of forests inthe avalanche path. We present an evaluation and improvement of a novel forestdetrainment function implemented in the avalanche simulation software RAMMS for avalanche simulation in forested terrain. The new approach accounts for the effect offorests in the avalanche path by detraining mass, which leads to a deceleration andrunout shortening of avalanches. The relationship is parameterized by the detrainmentcoefficientK(Pa) accounting for differing forest characteristics. We variedKwhensimulating 40 well-documented small- to medium-scale avalanches which released in and ran through forests of the Swiss Alps. Analyzing and comparing observed andsimulated runout distances statistically revealed values forKsuitable to simulate thecombined influence of four forest characteristics on avalanche runout: forest type,crown closure, vertical structure and surface roughness, e.g. values forKwere higherfor dense spruce and mixed spruce-beech forests compared to open larch forests at the upper treeline. Considering forest structural conditions within avalanche simulationwill improve current applications for avalanche simulation tools in mountain forest andnatural hazard management. Show more
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https://doi.org/10.3929/ethz-b-000074856Publication status
publishedExternal links
Journal / series
Natural Hazards and Earth System Sciences DiscussionsVolume
Pages / Article No.
Publisher
CopernicusOrganisational unit
03823 - Grêt-Regamey, Adrienne / Grêt-Regamey, Adrienne
02226 - NSL - Netzwerk Stadt und Landschaft / NSL - Network City and Landscape
02655 - Netzwerk Stadt u. Landschaft ARCH u BAUG / Network City and Landscape ARCH and BAUG
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Is previous version of: https://doi.org/10.3929/ethz-b-000554529
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