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| Titel |
On the importance of appropriate precipitation gauge catch correction for hydrological modelling at mid to high latitudes |
| VerfasserIn |
S. Stisen, A. L. Højberg, L. Troldborg, J. C. Refsgaard, B. S. B. Christensen, M. Olsen, H. J. Henriksen |
| 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 ; 16, no. 11 ; Nr. 16, no. 11 (2012-11-12), S.4157-4176 |
| Datensatznummer |
250013565
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| Publikation (Nr.) |
 copernicus.org/hess-16-4157-2012.pdf |
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| Zusammenfassung |
| Precipitation gauge catch correction is often given very little attention in
hydrological modelling compared to model parameter calibration. This is
critical because significant precipitation biases often make the
calibration exercise pointless, especially when supposedly physically-based
models are in play. This study addresses the general importance of
appropriate precipitation catch correction through a detailed modelling
exercise. An existing precipitation gauge catch correction method addressing
solid and liquid precipitation is applied, both as national mean monthly
correction factors based on a historic 30 yr record and as gridded daily
correction factors based on local daily observations of wind speed and
temperature. The two methods, named the historic mean monthly (HMM) and the
time–space variable (TSV) correction, resulted in different winter
precipitation rates for the period 1990–2010. The resulting precipitation
datasets were evaluated through the comprehensive Danish National Water
Resources model (DK-Model), revealing major differences in both model
performance and optimised model parameter sets. Simulated stream discharge
is improved significantly when introducing the TSV correction, whereas the
simulated hydraulic heads and multi-annual water balances performed
similarly due to recalibration adjusting model parameters to compensate for
input biases. The resulting optimised model parameters are much more
physically plausible for the model based on the TSV correction of
precipitation. A proxy-basin test where calibrated DK-Model parameters were
transferred to another region without site specific calibration showed
better performance for parameter values based on the TSV correction.
Similarly, the performances of the TSV correction method were superior when
considering two single years with a much dryer and a much wetter winter,
respectively, as compared to the winters in the calibration period
(differential split-sample tests). We conclude that TSV precipitation
correction should be carried out for studies requiring a sound dynamic
description of hydrological processes, and it is of particular importance
when using hydrological models to make predictions for future climates when
the snow/rain composition will differ from the past climate. This conclusion
is expected to be applicable for mid to high latitudes, especially in coastal
climates where winter precipitation types (solid/liquid) fluctuate
significantly, causing climatological mean correction factors to be
inadequate. |
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