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| Titel |
Flow-R, a model for susceptibility mapping of debris flows and other gravitational hazards at a regional scale |
| VerfasserIn |
P. Horton, M. Jaboyedoff, B. Rudaz, M. Zimmermann |
| 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 ; 13, no. 4 ; Nr. 13, no. 4 (2013-04-09), S.869-885 |
| Datensatznummer |
250018403
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| Publikation (Nr.) |
 copernicus.org/nhess-13-869-2013.pdf |
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| Zusammenfassung |
The development of susceptibility maps for debris flows is of primary
importance due to population pressure in hazardous zones. However, hazard
assessment by process-based modelling at a regional scale is difficult due to
the complex nature of the phenomenon, the variability of local controlling
factors, and the uncertainty in modelling parameters. A regional assessment
must consider a simplified approach that is not highly parameter dependant
and that can provide zonation with minimum data requirements. A distributed
empirical model has thus been developed for regional susceptibility
assessments using essentially a digital elevation model (DEM). The model is
called Flow-R for Flow path assessment of gravitational hazards at a
Regional scale (available free of charge under http://www.flow-r.org) and
has been successfully applied to different case studies in various countries
with variable data quality. It provides a substantial basis for a preliminary
susceptibility assessment at a regional scale. The model was also found
relevant to assess other natural hazards such as rockfall, snow avalanches
and floods.
The model allows for automatic source area delineation, given user criteria,
and for the assessment of the propagation extent based on various spreading
algorithms and simple frictional laws. We developed a new spreading
algorithm, an improved version of Holmgren's direction algorithm, that is
less sensitive to small variations of the DEM and that is avoiding
over-channelization, and so produces more realistic extents.
The choices of the datasets and the algorithms are open to the user, which
makes it compliant for various applications and dataset availability. Amongst
the possible datasets, the DEM is the only one that is really needed for both
the source area delineation and the propagation assessment; its quality is of
major importance for the results accuracy. We consider a 10 m DEM resolution
as a good compromise between processing time and quality of results. However,
valuable results have still been obtained on the basis of lower quality DEMs
with 25 m resolution. |
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