Review of manuscript «Determining the drivers for snow gliding» (Fromm et al. )

Abstract. Snow processes might be one important driver of soil erosion in Alpine grasslands and thus the unknown variable when erosion modelling is attempted. The aim of this study is to assess the importance of snow gliding as a soil erosion agent for four different land use/land cover types in a subalpine area in Switzerland. We used three different approaches to estimate soil erosion rates: sediment yield measurements in snow glide depositions, the fallout radionuclide 137Cs and modelling with the Revised Universal Soil Loss Equation (RUSLE). RUSLE permits the evaluation of soil loss by water erosion, the 137Cs method integrates soil loss due to all erosion agents involved, and the measurement of snow glide deposition sediment yield can be directly related to snow-glide-induced erosion. Further, cumulative snow glide distance was measured for the sites in the winter of 2009/2010 and modelled for the surrounding area and long-term average winter precipitation (1959–2010) with the spatial snow glide model (SSGM). Measured snow glide distance confirmed the presence of snow gliding and ranged from 2 to 189 cm, with lower values on the north-facing slopes. We observed a reduction of snow glide distance with increasing surface roughness of the vegetation, which is an important information with respect to conservation planning and expected and ongoing land use changes in the Alps. Snow glide erosion estimated from the snow glide depositions was highly variable with values ranging from 0.03 to 22.9 t ha−1 yr−1 in the winter of 2012/2013. For sites affected by snow glide deposition, a mean erosion rate of 8.4 t ha−1 yr−1 was found. The difference in long-term erosion rates determined with RUSLE and 137Cs confirms the constant influence of snow-glide-induced erosion, since a large difference (lower proportion of water erosion compared to total net erosion) was observed for sites with high snow glide rates and vice versa. Moreover, the difference between RUSLE and 137Cs erosion rates was related to the measured snow glide distance (R2 = 0.64; p < 0.005) and to the snow deposition sediment yields (R2 = 0.39; p = 0.13). The SSGM reproduced the relative difference of the measured snow glide values under different land uses and land cover types. The resulting map highlighted the relevance of snow gliding for large parts of the investigated area. Based on these results, we conclude that snow gliding appears to be a crucial and non-negligible process impacting soil erosion patterns and magnitude in subalpine areas with similar topographic and climatic conditions.

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Characteristics of snow gliding on rock

International Journal of Rock Mechanics and Mining Sciences & Geomechanics Abstracts ◽

10.1016/0148-9062(95)94840-6 ◽

1995 ◽

Vol 32 (2) ◽

pp. A97

Keyword(s):

Snow Gliding

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Estimation of soil redistribution rates due to snow cover related processes in a mountainous area (Valle d'Aosta, NW Italy)

Hydrology and Earth System Sciences ◽

10.5194/hess-16-517-2012 ◽

2012 ◽

Vol 16 (2) ◽

pp. 517-528 ◽

Cited By ~ 24

Author(s):

E. Ceaglio ◽

K. Meusburger ◽

M. Freppaz ◽

E. Zanini ◽

C. Alewell

Keyword(s):

Soil Erosion ◽

Sediment Yield ◽

Mountainous Area ◽

Mountain Areas ◽

Spatial And Temporal Scales ◽

Erosion Rates ◽

Soil Redistribution ◽

Erosion Processes ◽

Soil Accumulation ◽

Snow Gliding

Abstract. Mountain areas are widely affected by soil erosion, which is generally linked to runoff processes occurring in the growing season and snowmelt period. Also processes like snow gliding and full-depth snow avalanches may be important factors that can enhance soil erosion, however the role and importance of snow movements as agents of soil redistribution are not well understood yet. The aim of this study was to provide information on the relative importance of snow related processes in comparison to runoff processes. In the study area, which is an avalanche path characterized by intense snow movements, soil redistribution rates were quantified with two methods: (i) by field measurements of sediment yield in an avalanche deposition area during 2009 and 2010 winter seasons; (ii) by caesium-137 method, which supplies the cumulative net soil loss/gain since 1986, including all the soil erosion processes. The snow related soil accumulation estimated with data from the deposit area (27.5 Mg ha−1 event−1 and 161.0 Mg ha−1 event−1) was not only higher than the yearly sediment amounts, reported in literature, due to runoff processes, but it was even more intense than the yearly total deposition rate assessed with 137Cs (12.6 Mg ha−1 yr−1). The snow related soil erosion rates estimated from the sediment yield at the avalanche deposit area (3.7 Mg ha−1 and 20.8 Mg ha−1) were greater than the erosion rates reported in literature and related to runoff processes; they were comparable to the yearly total erosion rates assessed with the 137Cs method (13.4 Mg ha−1 yr−1 and 8.8 Mg ha−1 yr−1). The 137Cs method also showed that, where the ground avalanche does not release, the erosion and deposition of soil particles from the upper part of the basin was considerable and likely related to snow gliding. Even though the comparison of both the approaches is linked to high methodological uncertainties, mainly due to the different spatial and temporal scales considered, we still can deduce, from the similarity of the erosion rates, that soil redistribution in this catchment is driven by snow movement, with a greater impact in comparison to the runoff processes occurring in the snow-free season. Nonetheless, the study highlights that soil erosion processes due to the snow movements should be considered in the assessment of soil vulnerability in mountain areas, as they significantly determine the pattern of soil redistribution.

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Determining the drivers for snow gliding

10.5194/nhess-2018-3 ◽

2018 ◽

Author(s):

Reinhard Fromm ◽

Sonja Baumgärtner ◽

Georg Leitinger ◽

Erich Tasser ◽

Peter Höller

Keyword(s):

Soil Moisture ◽

Soil Surface ◽

Test Site ◽

Negative Influence ◽

Important Variable ◽

High Temporal Resolution ◽

Soil Layers ◽

Key Factor ◽

Avalanche Formation ◽

Snow Gliding

Abstract. Snow gliding is a key factor for snow glide avalanche formation and soil erosion. This study considers atmospheric and snow variables, vegetation characteristics, and soil properties, and determines their relevance for snow gliding at a test site (Wildkogel, Upper Pinzgau, Austria) during winter 2014/15. The time-dependent data were collected at a high temporal resolution. In addition to conventional sensors a snow melt analyzer was used. The analysis shows that the soil moisture at the soil surface had the largest influence on snow gliding during the first part of the winter (October to January). The soil moisture 1.5 cm below the soil surface was the second important variable in the first part of the winter, and the most important variable in the second part of the winter (February to May). A negative influence on snow gliding had the phytomass of mosses in autumn and spring caused by lower canopy heights at these sites. Furthermore, a higher portion of dwarf shrub phytomass reduces snow gliding, because its rigid structure can transfer forces to the soil. Further investigations may be focused on the freezing and melting processes in the uppermost soil layers, and at the soil surface.

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Full-depth avalanche occurrences caused by snow gliding, Coquihalla, British Columbia, Canada

Journal of Glaciology ◽

10.3189/s0022143000001404 ◽

1999 ◽

Vol 45 (151) ◽

pp. 539-546 ◽

Cited By ~ 1

Author(s):

Jennifer Clarke ◽

David McClung

Keyword(s):

British Columbia ◽

Stainless Steel ◽

Ground Surface ◽

Free Water ◽

Important Influence ◽

Reliable Indicator ◽

Climate Data ◽

Cascade Mountains ◽

Sloping Ground ◽

Snow Gliding

AbstractSnow glide is the translational slip of the entire snowpack over a sloping ground surface, and it is thought that rapid rates of snow glide precede full-depth avalanches. The nature of avalanches that release at the ground makes them difficult to predict and difficult to control using explosives.On-slope instrumentation comprised of stainless-steel "glide shoes" was used to measure rates of snow glide for two winters on a bedrock slope adjacent to the Coquihalla Highway, Cascade Mountains, British Columbia, Canada. Climate data and avalanche occurrences were recorded by the British Columbia Ministry of Transportation and Highways.Our results show that the supply of free water to the snow/ground interface by rain or snowmelt is the most important influence on full-depth avalanche release. Full-depth avalanche release responds to rainfall and snowmelt events within 12-24 hours. Occasionally, full-depth avalanches occur unexpectedly during clear, cold periods. Snowmelt by radiation is thought to contribute enough meltwater during these cold periods to induce higher rates of snow glide and full-depth avalanche release. The results also indicate that snow glide alone is not a reliable indicator for full-depth avalanche release.

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A physical theory of snow gliding

Canadian Geotechnical Journal ◽

10.1139/t81-008 ◽

1981 ◽

Vol 18 (1) ◽

pp. 86-94 ◽

Cited By ~ 15

Author(s):

David M. McClung

Keyword(s):

Rigid Body ◽

Constitutive Equations ◽

Slip Velocity ◽

Physical Theory ◽

Water Film ◽

Point Of View ◽

Slip Condition ◽

Realistic Case ◽

Viscous Deformation ◽

Snow Gliding

Snow glide, slip of the entire snowpack over the ground, is not observed unless water reaches the ground interface. In this paper, snow gliding is approached from the point of view that a perfect slip condition is attained at the glide interface whereby a thin continuous water film is envisioned to exist between the snowpack and the ground. Two mechanisms are described by which the snowpack may move forward: (i) creep (defined as slow, viscous deformation) over roughness asperities under the condition that the snowpack conforms to the interface and (ii) rigid body sliding of the snowpack over the interface when it does not conform to the interface. Constitutive equations relating tangential drag on the snowpack to slip velocity are derived for these idealized cases, and the extension to the more realistic case where the processes compete is discussed.

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