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| Titel |
Spectral parameterisation of rainfall-runoff models in ungauged basins |
| VerfasserIn |
S. Castiglioni, A. Montanari, A. Castellarin |
| Konferenz |
EGU General Assembly 2009
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 11 (2009) |
| Datensatznummer |
250030206
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| Zusammenfassung |
| Parameter estimation of rainfall-runoff models in ungauged basins is a challenging task that is
often dealt with in practical applications, given that hydrological observations are often
sparse or unavailable in many countries of the world. This study focuses on calibrating an
assigned rainfall-runoff model basing on its spectral properties. Spectral calibration offers
the advantage of exploiting the persistence and variability behaviours of the river
flow regime, which in turn can be effectively related to the dominant climate and
catchment behaviours. In detail, we propose to estimate the spectral properties of
the river flow regime depending on geomorphological and climatic descriptors of
the contributing catchment, and calibrate the hydrological model by optimising
the fit of the spectral properties themselves. The proposed techniques is applied
to 13 basins located in central Italy, that were treated as ungauged. In particular,
an extended analysis has been carried out to relate the spectral properties of river
flow, resembled by the mean value, μ, variance, Ï2, and lag-one autocorrelation
coefficient, Ï1, of the river discharge series, to the geomorphological and climatic
characteristics of the contributing catchment. An automatic optimisation is then used to
identify the optimal set of model parameters, by minimising the weighed sum of the
relative squared errors in the reproduction of μ, Ï2 and Ï1. The results confirm the
effectiveness of proposed methodology and show that the spectral properties of the river
discharge contain important information about the hydrological regime of a given basin. |
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