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| Titel |
Introduction of a simple-model-based land surface dataset for Europe |
| VerfasserIn |
Rene Orth, Sonia I. Seneviratne |
| Konferenz |
EGU General Assembly 2015
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 17 (2015) |
| Datensatznummer |
250105351
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| Publikation (Nr.) |
 EGU/EGU2015-8674.pdf |
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| Zusammenfassung |
| Land surface hydrology is important because it can play a crucial role during extreme
events such as droughts, floods and even heat waves. We introduce in this study a new
hydrological dataset for the European continent that consists of soil moisture, runoff
and evapotranspiration. It is derived with a simple water balance model (SWBM)
forced with precipitation, temperature and net radiation. The SWBM dataset covers
Europe and extends over the period 1984-2013 with a daily time step and 0.5°x0.5°
resolution. We employ a novel approach to calibrate the model, whereby we consider
300 random parameter sets chosen from an observation-based range. Using several
independent validation datasets representing soil moisture (or terrestrial water content),
evapotranspiration and streamflow, we identify the best performing parameter set and
hence the new dataset. To illustrate its usefulness, the SWBM dataset is compared
against ERA-Interim/Land and simulations of the Community Land Model Version 4,
using all validation datasets as reference. For soil moisture dynamics it outperforms
the benchmarks. Therefore the SWBM soil moisture dataset constitutes a reasonable
alternative to sparse measurements, little validated model results, or proxy data such as
precipitation indices. In terms of runoff the SWBM dataset also performs well versus the
benchmarks. They all show a slight dry bias which is probably due to underestimated
precipitation used to force the model. The evaluation of the SWBM evapotranspiration
dataset is overall satisfactory, but the dynamics are less well captured for this variable.
This highlights the limitations of the dataset, as it is based on a simple model that
uses uniform parameter values. Hence some processes impacting evapotranspiration
dynamics may not be captured, and quality issues may occur in regions with complex
terrain. Furthermore we investigate the sources of skill of the SWBM dataset and find
that the parameter set has a similar impact on the simple model results as the choice
of the forcing dataset. The newly derived SWBM dataset is of relevance for a range
of applications given the deficit of available land datasets. It will be made publicly
available on the web upon publication of the corresponding article. |
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