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| Titel |
Performance and reliability of multimodel hydrological ensemble simulations based on seventeen lumped models and a thousand catchments |
| VerfasserIn |
J. A. Velázquez, F. Anctil, C. Perrin |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1027-5606
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| Digitales Dokument |
URL |
| Erschienen |
In: Hydrology and Earth System Sciences ; 14, no. 11 ; Nr. 14, no. 11 (2010-11-18), S.2303-2317 |
| Datensatznummer |
250012485
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| Publikation (Nr.) |
 copernicus.org/hess-14-2303-2010.pdf |
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| Zusammenfassung |
| This work investigates the added value of ensembles constructed from
seventeen lumped hydrological models against their simple average
counterparts. It is thus hypothesized that there is more information
provided by all the outputs of these models than by their single aggregated
predictors. For all available 1061 catchments, results showed that the mean
continuous ranked probability score of the ensemble simulations were better
than the mean average error of the aggregated simulations, confirming the
added value of retaining all the components of the model outputs.
Reliability of the simulation ensembles is also achieved for about 30% of
the catchments, as assessed by rank histograms and reliability plots.
Nonetheless this imperfection, the ensemble simulations were shown to have
better skills than the deterministic simulations at discriminating between
events and non-events, as confirmed by relative operating characteristic
scores especially for larger streamflows. From 7 to 10 models are deemed
sufficient to construct ensembles with improved performance, based on a
genetic algorithm search optimizing the continuous ranked probability score.
In fact, many model subsets were found improving the performance of the
reference ensemble. This is thus not essential to implement as much as
seventeen lumped hydrological models. The gain in performance of the
optimized subsets is accompanied by some improvement of the ensemble
reliability in most cases. Nonetheless, a calibration of the predictive
distribution is still needed for many catchments. |
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