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| Titel |
Isotopic separation of snowmelt runoff during an artificial rain-on-snow event |
| VerfasserIn |
Roman Juras, Jirka Pavlasek, Martin Sanda, Jakub Jankovec, Miloslav Linda |
| Konferenz |
EGU General Assembly 2013
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 15 (2013) |
| Datensatznummer |
250083161
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| Zusammenfassung |
| Rain-on-snow events are common phenomenon in the climate conditions of central Europe,
mainly during the spring snowmelt period. These events can cause serious floods in areas
with seasonal snow. The snowpack hit by rain is able to store a fraction of rain water, but
runoff caused by additional snowmelt also increases. Assessment of the rainwater ratio
contributing to the outflow from the snowpack is therefore critical for discharge
modelling.
A rainfall simulator and water enriched by deuterium were used for the study of rainwater
behaviour during an artificial rain-on-snow event. An area of 1 m2 of the snow sample, which
was 1.2 m deep, consisting of ripped coarse-grained snow, was sprayed during the experiment
with deuterium enriched water. The outflow from the snowpack was measured and samples of
outflow water were collected. The isotopic content of deuterium was further analyzed from
these samples by means of laser spectroscopy for the purpose of hydrograph separation.
The concentration of deuterium in snow before and after the experiment was also
investigated.
The deuterium enriched water above the natural concentration of deuterium in snowpack was
detected in the outflow in 7th minute from start of spraying, but the significant increase of
deuterium concentration in outflow was observed in 19th minute. The isotopic hydrograph
separation estimated, that deuterium enriched rainwater became the major part (> 50%
volumetric) of the outflow in 28th minute. The culmination of the outflow (1.23 l min-1) as
well as deuterium enriched rainwater fraction (63.5%) in it occurred in 63th minute,
i.e. right after the end of spraying. In total, 72.7 l of deuterium enriched water was
sprayed on the snowpack in 62 minutes. Total volume of outflow (after 12.3 hours)
water was 97.4 l, which contained 48.3 l of deuterium enriched water (i.e. 49.6 %)
and 49.1 l (50.4 %) of the melted snowpack. The volume of 24.4 l of deuterium
enriched spray-water was stored in the snowpack. The increased total output v. input of
the water volume was caused by the warmer spray-water induced snowmelt also
connecting separated liquid layers in the snowpack within the process of infiltration and
drainage.
Key words: deuterium tracer, rainfall simulator, snowmelt |
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