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Titel |
Influence of snow depth distribution on surface roughness in alpine terrain: a multi-scale approach |
VerfasserIn |
J. Veitinger, B. Sovilla, R. S. Purves |
Medientyp |
Artikel
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Sprache |
Englisch
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ISSN |
1994-0416
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Digitales Dokument |
URL |
Erschienen |
In: The Cryosphere ; 8, no. 2 ; Nr. 8, no. 2 (2014-04-03), S.547-569 |
Datensatznummer |
250116085
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Publikation (Nr.) |
copernicus.org/tc-8-547-2014.pdf |
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Zusammenfassung |
In alpine terrain, the snow-covered winter surface deviates from its
underlying summer terrain due to the progressive smoothing caused by snow
accumulation. Terrain smoothing is believed to be an important factor in
avalanche formation and avalanche dynamics, and it affects surface heat transfer,
energy balance as well as snow depth distribution. To assess the effect of
snow on terrain, we use an adequate roughness definition. We developed a
method to quantify terrain smoothing by combining roughness calculations of
snow surfaces and their corresponding underlying terrain with snow depth
measurements. To this end, elevation models of winter and summer terrain in
three selected alpine basins in the Swiss Alps characterized by low, medium
and high terrain roughness were derived from high-resolution measurements
performed by airborne and terrestrial lidar. The preliminary results in the
selected basins reveal that, at basin scale, terrain smoothing depends not only
on mean snow depth in the basin but also on its variability. The
multi-temporal analysis over three winter seasons in one basin suggests that
terrain smoothing can be modelled as a function of mean snow depth and its
standard deviation using a power law. However, a relationship between terrain
smoothing and snow depth was not found at pixel scale. Further, we show that
snow surface roughness is to some extent persistent, even in-between winter
seasons. Those persistent patterns might be very useful to improve the
representation of a winter terrain without modelling of the snow cover
distribution. This can for example improve avalanche release area definition
and, in the long term, natural hazard management strategies. |
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