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Titel |
A conceptual, distributed snow redistribution model |
VerfasserIn |
S. Frey, H. Holzmann |
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 ; 19, no. 11 ; Nr. 19, no. 11 (2015-11-12), S.4517-4530 |
Datensatznummer |
250120848
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Publikation (Nr.) |
copernicus.org/hess-19-4517-2015.pdf |
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Zusammenfassung |
When applying conceptual hydrological models using a temperature index
approach for snowmelt to high alpine areas often accumulation of snow during
several years can be observed. Some of the reasons why these "snow towers"
do not exist in nature are vertical and lateral transport processes. While
snow transport models have been developed using grid cell sizes of tens to
hundreds of square metres and have been applied in several catchments, no
model exists using coarser cell sizes of 1 km2, which is a
common resolution for meso- and large-scale hydrologic modelling (hundreds to
thousands of square kilometres). In this paper we present an approach that
uses only gravity and snow density as a proxy for the age of the snow cover
and land-use information to redistribute snow in alpine basins. The results
are based on the hydrological modelling of the Austrian Inn Basin in Tyrol,
Austria, more specifically the Ötztaler Ache catchment, but the findings
hold for other tributaries of the river Inn. This transport model is
implemented in the distributed rainfall–runoff model COSERO (Continuous Semi-distributed Runoff). The results of
both model concepts with and without consideration of lateral snow
redistribution are compared against observed discharge and snow-covered
areas derived from MODIS satellite images. By means of the snow
redistribution concept, snow accumulation over several years can be prevented
and the snow depletion curve compared with MODIS (Moderate Resolution Imaging Spectroradiometer) data could be improved,
too. In a 7-year period the standard model would lead to snow
accumulation of approximately 2900 mm SWE (snow water equivalent) in high elevated regions whereas
the updated version of the model does not show accumulation and does also
predict discharge with more accuracy leading to a Kling–Gupta efficiency of
0.93 instead of 0.9. A further improvement can be shown in the comparison of
MODIS snow cover data and the calculated depletion curve, where the
redistribution model increased the efficiency (R2) from 0.70 to 0.78
(calibration) and from 0.66 to 0.74 (validation). |
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