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| Titel |
A simplified rainfall-runoff stochastic simulation method for an application of the SCHADEX method to ungauged catchments. |
| VerfasserIn |
David Penot, Emmanuel Paquet, Michel Lang |
| Konferenz |
EGU General Assembly 2014
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 16 (2014) |
| Datensatznummer |
250087677
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| Publikation (Nr.) |
 EGU/EGU2014-1737.pdf |
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| Zusammenfassung |
| SCHADEX is a probabilistic method for extreme flood estimation, developed and applied
since 2006 at Electricité de France (EDF) for dam spillway design [Paquet et al., 2013].
SCHADEX is based on a semi-continuous rainfall-runoff simulation process. The method has
been built around two models: a Multi-Exponential Weather Pattern (MEWP) distribution for
rainfall probability estimation [Garavaglia et al., 2010] and the MORDOR hydrological
model.
To use SCHADEX in ungauged context, rainfall distribution and hydrological model
must be regionalized. The regionalization of the MEWP rainfall distribution can be managed
with SPAZM, a daily rainfall interpolator [Gottardi et al., 2012] which provides reasonable
estimates of point and areal rainfall up to hight quantiles. The main issue remains to
regionalize MORDOR which is heavily parametrized.
A much more simple model has been considered: the SCS model. It is a well
known model for event simulation [USDA SCS, 1985; Beven, 2003] and it relies on
only one parameter. Then, the idea is to use the SCS model instead of MORDOR
within a simplified stochastic simulation scheme to produce a distribution of flood
volume from an exhaustive crossing between rainy events and catchment saturation
hazards.
The presentation details this process and its capacity to generate a runoff distribution
based on catchment areal rainfall distribution. The simulation method depends on a unique
parameter Smax, the maximum initial loss of the catchment. Then an initial loss S
(between zero and Smax) can be drawn to account for the variability of catchment
state (between dry and saturated). The distribution of initial loss (or conversely,
of catchment saturation, as modeled by MORDOR) seems closely linked to the
catchment’s regime, therefore easily to regionalize. The simulation takes into account
a snow contribution for snow driven catchments, and an antecedent runoff. The
presentation shows the results of this stochastic procedure applied on 80 French
catchments and its capacity to represent the asymptotic behaviour of the runoff
distribution.
References:
K. J. Beven. Rainfall-Runoff modelling The Primer, British Library, 2003.
F. Garavaglia, J. Gailhard, E. Paquet, M. Lang, R. Garçon, and P. Bernardara. Introducing a
rainfall compound distribution model based on weather patterns sub-sampling. Hydrology
and Earth System Sciences, 14(6):951–964, 2010.
F. Gottardi, C. Obled, J. Gailhard, and E. Paquet. Statistical reanalysis of precipitation fields
based on ground network data and weather patterns : Application over french mountains.
Journal of Hydrology, 432–433:154–167, 2012. ISSN 0022-1694.
E. Paquet, F. Garavaglia, R Garçon, and J. Gailhard. The schadex method : a semi-continuous
rainfall-runoff simulation for extreme flood estimation. Journal of Hydrology, 2013.
USDA SCS, National Engineering Handbook, Supplement A, Section 4, Chapter 10.
Whashington DC, 1985. |
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