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Titel |
Tree-ring based reconstruction of the seasonal timing, major events and origin of rockfall on a case-study slope in the Swiss Alps |
VerfasserIn |
D. M. Schneuwly, M. Stoffel |
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 Science ; 8, no. 2 ; Nr. 8, no. 2 (2008-03-11), S.203-211 |
Datensatznummer |
250005402
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Publikation (Nr.) |
copernicus.org/nhess-8-203-2008.pdf |
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Zusammenfassung |
Tree-ring analysis has been used to reconstruct 22 years of rockfall
behavior on an active rockfall slope near Saas Balen (Swiss Alps). We
analyzed 32 severely injured trees (L. decidua, P. abies and P. cembra) and investigated cross-sections
of 154 wounds.
The intra-annual position of callus tissue and of tangential rows of
traumatic resin ducts was determined in order to reconstruct the seasonality
of past rockfall events. Results indicate strong intra- and inter-annual
variations of rockfall activity, with a peak (76%) observed in the
dormant season (early October – end of May). Within the growth season,
rockfall regularly occurs between the end of May and mid July (21.4%),
whereas events later in the season appear to be quite rare (2.6%).
Findings suggest that rockfall activity at the study site is driven by
annual thawing processes and the circulation of melt water in preexisting
fissures. Data also indicate that 43% of all rockfall events occurred in
1995, when two major precipitation events are recorded in nearby
meteorological stations. Finally, data on impact angles are in very good
agreement with the geomorphic situation in the field. |
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