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| Titel |
Debris-flow activity in abandoned channels of the Manival torrent reconstructed with LiDAR and tree-ring data |
| VerfasserIn |
J. Lopez Saez, C. Corona, M. Stoffel, A. Gotteland, F. Berger, F. Liébault |
| 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 ; 11, no. 5 ; Nr. 11, no. 5 (2011-05-09), S.1247-1257 |
| Datensatznummer |
250009407
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| Publikation (Nr.) |
 copernicus.org/nhess-11-1247-2011.pdf |
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| Zusammenfassung |
| Hydrogeomorphic processes are a major threat in many parts of the Alps,
where they periodically damage infrastructure, disrupt transportation
corridors or even cause loss of life. Nonetheless, past torrential activity
and the analysis of areas affected during particular events remain often
imprecise. It was therefore the purpose of this study to reconstruct
spatio-temporal patterns of past debris-flow activity in abandoned channels
on the forested cone of the Manival torrent (Massif de la Chartreuse, French
Prealps). A Light Detecting and Ranging (LiDAR) generated Digital Elevation
Model (DEM) was used to identify five abandoned channels and related
depositional forms (lobes, lateral levees) in the proximal alluvial fan of
the torrent. A total of 156 Scots pine trees (Pinus sylvestris L.) with clear signs of
debris flow events was analyzed and growth disturbances (GD) assessed, such
as callus tissue, the onset of compression wood or abrupt growth
suppression. In total, 375 GD were identified in the tree-ring samples,
pointing to 13 debris-flow events for the period 1931–2008. While debris
flows appear to be very common at Manival, they have only rarely propagated
outside the main channel over the past 80 years. Furthermore, analysis of
the spatial distribution of disturbed trees contributed to the
identification of four patterns of debris-flow routing and led to the
determination of three preferential breakout locations. Finally, the results
of this study demonstrate that the temporal distribution of debris flows did
not exhibit significant variations since the beginning of the 20th
century. |
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