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| Titel |
Flood modelling with a distributed event-based parsimonious rainfall-runoff model: case of the karstic Lez river catchment |
| VerfasserIn |
M. Coustau, C. Bouvier, V. Borrell-Estupina, H. Jourde |
| 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 ; 12, no. 4 ; Nr. 12, no. 4 (2012-04-20), S.1119-1133 |
| Datensatznummer |
250010706
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| Publikation (Nr.) |
 copernicus.org/nhess-12-1119-2012.pdf |
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| Zusammenfassung |
| Rainfall-runoff models are crucial tools for the statistical prediction of
flash floods and real-time forecasting. This paper focuses on a karstic
basin in the South of France and proposes a distributed parsimonious
event-based rainfall-runoff model, coherent with the poor knowledge of both
evaporative and underground fluxes. The model combines a SCS runoff model
and a Lag and Route routing model for each cell of a regular grid mesh. The
efficiency of the model is discussed not only to satisfactorily simulate
floods but also to get powerful relationships between the initial condition
of the model and various predictors of the initial wetness state of the
basin, such as the base flow, the Hu2 index from the Meteo-France SIM model
and the piezometric levels of the aquifer. The advantage of using
meteorological radar rainfall in flood modelling is also assessed. Model
calibration proved to be satisfactory by using an hourly time step with Nash
criterion values, ranging between 0.66 and 0.94 for eighteen of the
twenty-one selected events. The radar rainfall inputs significantly improved
the simulations or the assessment of the initial condition of the model for
5 events at the beginning of autumn, mostly in September–October (mean
improvement of Nash is 0.09; correction in the initial condition ranges from
−205 to 124 mm), but were less efficient for the events at the end of
autumn. In this period, the weak vertical extension of the precipitation
system and the low altitude of the 0 °C isotherm could affect the
efficiency of radar measurements due to the distance between the basin and
the radar (~60 km). The model initial condition S is correlated with
the three tested predictors (R2 > 0.6). The interpretation of the
model suggests that groundwater does not affect the first peaks of the
flood, but can strongly impact subsequent peaks in the case of a multi-storm
event. Because this kind of model is based on a limited amount of readily
available data, it should be suitable for operational applications. |
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