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Titel |
Hortonian runoff closure relations for geomorphologic response units: evaluation against field data |
VerfasserIn |
E. Vannametee, D. Karssenberg, M. R. Hendriks, M. F. P. Bierkens |
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 ; 17, no. 7 ; Nr. 17, no. 7 (2013-07-26), S.2981-3004 |
Datensatznummer |
250018949
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Publikation (Nr.) |
copernicus.org/hess-17-2981-2013.pdf |
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Zusammenfassung |
This paper presents an evaluation of the closure relation for Hortonian
runoff, proposed in Vannametee et al. (2012),
that incorporates a scaling component to explicitly account for the process
heterogeneity and scale effects in runoff generation for the real-world case
studies. We applied the closure relation, which was embedded in an
event-based lumped rainfall–runoff model, to a 15 km2 catchment in the
French Alps. The catchment was disaggregated into a number of landform
units, referred to as Geomorphologic Response Units (GRUs), to each of which
the closure relation was applied. The scaling component in the closure
relation was identified using the empirical relations between rainstorm
characteristics, geometry, and local-scale measurable properties of the
GRUs. Evaluation of the closure relation performance against the observed
discharge shows that the hydrograph and discharge volume were quite
satisfactorily simulated even without calibration. Performance of the
closure relation can be mainly attributed to the use of scaling component,
as it is shown that our closure relation outperforms a benchmark closure
relation that lacks this scaling component. The discharge prediction is
significantly improved when the closure relation is calibrated against the
observed discharge, resulting in local-scale GRU-properties optimal for the
predictions. Calibration was done by changing one local-scale observable,
i.e. hydraulic conductivity (Ks), using a single pre-factor for the
entire catchment. It is shown that the calibrated Ks values are somewhat
comparable to the observed Ks values at a local scale in the study
catchment. These results suggest that, in the absence of discharge
observations, reasonable estimates of catchment-scale runoff responses can
possibly be achieved with the observations at the sub-GRU (i.e. plot) scale.
Our study provides a platform for the future development of low-dimensional,
semi-distributed, physically based discharge models in ungauged
catchments. |
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