|
Titel |
Estimation of soil redistribution rates due to snow cover related processes in a mountainous area (Valle d'Aosta, NW Italy) |
VerfasserIn |
E. Ceaglio, K. Meusburger, M. Freppaz, E. Zanini, C. Alewell |
Medientyp |
Artikel
|
Sprache |
Englisch
|
ISSN |
1027-5606
|
Digitales Dokument |
URL |
Erschienen |
In: Hydrology and Earth System Sciences ; 16, no. 2 ; Nr. 16, no. 2 (2012-02-17), S.517-528 |
Datensatznummer |
250013180
|
Publikation (Nr.) |
copernicus.org/hess-16-517-2012.pdf |
|
|
|
Zusammenfassung |
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. |
|
|
Teil von |
|
|
|
|
|
|