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| Titel |
A comparative assessment of two different debris flow propagation approaches – blind simulations on a real debris flow event |
| VerfasserIn |
L. M. Stancanelli, E. Foti |
| 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 Sciences ; 15, no. 4 ; Nr. 15, no. 4 (2015-04-07), S.735-746 |
| Datensatznummer |
250119414
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| Publikation (Nr.) |
 copernicus.org/nhess-15-735-2015.pdf |
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| Zusammenfassung |
| A detailed comparison between the performances of two different approaches to
debris flow modelling was carried out. In particular, the results of a
mono-phase Bingham model (FLO-2D) and that of a two-phase model (TRENT-2D)
obtained from a blind test were compared. As a benchmark test the
catastrophic event of 1 October 2009 which struck Sicily
causing several fatalities and damage was chosen. The predicted temporal
evolution of several parameters of the debris flow (such as flow depth and
propagation velocity) was analysed in order to investigate the
advantages and disadvantages of the two models in reproducing the global
dynamics of the event. An analysis between the models' results with survey
data have been carried out, not only for the determination of statistical
indicators of prediction accuracy, but also for the application of the
Receiver Operator Characteristic (ROC) approach. Provided that the proper
rheological parameters and boundary conditions are assigned, both models seem
capable of reproducing the inundation areas in a reasonably accurate way.
However, the main differences in the application rely on the choice of such
rheological parameters. Indeed, within the more user-friendly FLO-2D model
the tuning of the parameters must be done empirically, with no evidence of
the physics of the phenomena. On the other hand, for the TRENT-2D the
parameters are physically based and can be estimated from the properties of
the solid material, thus reproducing more reliable results. A second
important difference between the two models is that in the first method the
debris flow is treated as a homogeneous flow, in which the total mass is kept
constant from its initiation in the upper part of the basin to the
deposition in a debris fan. In contrast, the second approach is suited to
reproduce the erosion and deposition processes and the displaced mass can be
directly related to the rainfall event. Application of both models in a
highly urbanized area reveals the limitation of numerical simulation which is
inadequate in describing some disturbances of the flows that occurred during the
alluvial event (e.g. the cars, the volume of debris within buildings etc.)
which have a crucial influence on the evaluation of the maximum and final
flow depths. |
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