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| Titel |
Soil erosion in an avalanche release site (Valle d'Aosta: Italy): towards a winter factor for RUSLE in the Alps |
| VerfasserIn |
S. Stanchi, M. Freppaz, E. Ceaglio, M. Maggioni, K. Meusburger, C. Alewell, E. Zanini |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1561-8633
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| Digitales Dokument |
URL |
| Erschienen |
In: Natural Hazards and Earth System Sciences ; 14, no. 7 ; Nr. 14, no. 7 (2014-07-16), S.1761-1771 |
| Datensatznummer |
250118542
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| Publikation (Nr.) |
 copernicus.org/nhess-14-1761-2014.pdf |
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| Zusammenfassung |
| Soil erosion in Alpine areas is mainly related to extreme topographic and
weather conditions. Although different methods of assessing soil erosion
exist, the knowledge of erosive forces of the snow cover needs more
investigation in order to allow soil erosion modeling in areas where the snow
lays on the ground for several months. This study aims to assess whether the
RUSLE (Revised Universal Soil Loss Equation) empirical prediction model,
which gives an estimation of water erosion in t ha yr−1 obtained from
a combination of five factors (rainfall erosivity, soil erodibility,
topography, soil cover, protection practices) can be applied to mountain
areas by introducing a winter factor (W), which should account for the soil
erosion occurring in winter time by the snow cover. The W factor is
calculated from the ratio of Ceasium-137 (137Cs) to RUSLE erosion rates.
Ceasium-137 is another possible way of assessing soil erosion rates in the
field. In contrast to RUSLE, it not only provides water-induced erosion but
integrates all erosion agents involved. Thus, we hypothesize that in mountain
areas the difference between the two approaches is related to the soil
erosion by snow. In this study we compared 137Cs-based measurement of
soil redistribution and soil loss estimated with RUSLE in a mountain slope
affected by avalanches, in order to assess the relative importance of winter
erosion processes such as snow gliding and full-depth avalanches. Three
subareas were considered: DS, avalanche defense structures, RA, release area,
and TA, track area, characterized by different prevalent winter processes.
The RUSLE estimates and the 137Cs redistribution gave significantly
different results. The resulting ranges of W evidenced relevant differences
in the role of winter erosion in the considered subareas, and the application
of an avalanche simulation model corroborated these findings. Thus, the
higher rates obtained with the 137Cs method confirmed the relevant role
of winter soil erosion. Despite the limited sample size (11 points), the
inclusion of a W factor in RUSLE seems promising for the improvement of
soil erosion estimates in Alpine environments affected by snow movements. |
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