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| Titel |
Geomorphometric analysis of shallow landslides in the Walgau valley (Austria) |
| VerfasserIn |
Gregor Lützenburg, Elmar Schmaltz, Thomas Glade |
| Konferenz |
EGU General Assembly 2017
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| Medientyp |
Artikel
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| Sprache |
en
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 19 (2017) |
| Datensatznummer |
250153987
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| Publikation (Nr.) |
 EGU/EGU2017-19029.pdf |
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| Zusammenfassung |
| Hydrologically triggered shallow landslides are a frequent natural hazard in the Eastern Alps
and can cause severe damages to agriculturally used land, houses and infrastructure.
Geomorphometric indices allow to estimate the spatial dynamics of shallow landslides based
on recurrent landslide inventories. Previous studies found that the morphology of a
landslip is closely related to its dominant genetic process. In this study, we focus on
the calculation of established geomorphometric indices of the prevailing shallow
landslides to assess the spatial landslide distribution in the Walgau valley in Vorarlberg
(Austria).
Therefore, we compiled a multi-temporal landslide inventory based on eight orthophoto
series from 1950 to 2015 and two digital terrain models derived from airborne laser scanning
(ALS) data of 2004 and 2011. The 123 mapped landslides and adjacent areas were further
distinguished in distinct geomorphic features, such as parent slope, landslide scarp, concave
(surface of rupture) and convex (mass material) segments. Lithological settings and
anthropogenic impacts such as land use change were also considered in the analysis. A
geomorphometric assessment of the mapped landslides, in combination with land cover
information yields insights on the spatial dimension of the shallow landslides and the
potential fluidity of the materials involved. The geomorphometric analyses revealed that 96
landslides were classified as fluid-flows, 17 landslides were classified as viscous-flows, 8
landslides were classified as slide-flows and 2 landslides were classified as planar
slides.
Our findings indicate that most of the shallow landslides display a flow-like movement
with a rather low material plasticity. This leads to the assumption that the observed landslides
in the investigated area might be of low kinetic energy despite their relatively long travel
distances. Spatial disparities within the study area were not observable. We conclude that
geomorphometric indices are a powerful tool to investigate and estimate the spatial
distribution of shallow landslides. |
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