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| Titel |
A fully automated meltwater monitoring and collection system for spatially distributed isotope analysis in snowmelt-dominated catchments |
| VerfasserIn |
Andrea Rücker, Stefan Boss, Jana Von Freyberg, Massimiliano Zappa, James Kirchner |
| Konferenz |
EGU General Assembly 2016
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| Medientyp |
Artikel
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| Sprache |
en
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 18 (2016) |
| Datensatznummer |
250125127
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| Publikation (Nr.) |
 EGU/EGU2016-4661.pdf |
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| Zusammenfassung |
| In many mountainous catchments the seasonal snowpack stores a significant volume of
water, which is released as streamflow during the melting period. The predicted
change in future climate will bring new challenges in water resource management in
snow-dominated headwater catchments and their receiving lowlands. To improve predictions
of hydrologic extreme events, particularly summer droughts, it is important characterize
the relationship between winter snowpack and summer (low) flows in such areas
(e.g., Godsey et al., 2014). In this context, stable water isotopes (18O, 2H) are a
powerful tool for fingerprinting the sources of streamflow and tracing water flow
pathways.
For this reason, we have established an isotope sampling network in the Alptal catchment
(46.4 km2) in Central-Switzerland as part of the SREP-Drought project (Snow Resources
and the Early Prediction of hydrological DROUGHT in mountainous streams). Samples of
precipitation (daily), snow cores (weekly) and runoff (daily) are analyzed for their isotopic
signature in a regular cycle. Precipitation is also sampled along a horizontal transect at the
valley bottom, and along an elevational transect. Additionally, the analysis of snow meltwater
is of importance.
As the sample collection of snow meltwater in mountainous terrain is often impractical,
we have developed a fully automatic snow lysimeter system, which measures meltwater
volume and collects samples for isotope analysis at daily intervals. The system consists of
three lysimeters built from Decagon-ECRN-100 High Resolution Rain Gauges as standard
component that allows monitoring of meltwater flow. Each lysimeter leads the meltwater into
a 10-liter container that is automatically sampled and then emptied daily. These
water samples are replaced regularly and analyzed afterwards on their isotopic
composition in the lab. Snow melt events as well as system status can be monitored in real
time.
In our presentation we describe the automatic snow lysimeter system and present initial
results from field tests in winter 2015/2016 under natural conditions at an experimental field
site. Fully functional deployment in a forested and an open field location in the Erlenbach
subcatchment (0.7 km2) is envisaged for winter 2016/2017.
Godsey, S.E.,* J.W. Kirchner and C.L. Tague, Effects of changes in winter snowpacks on
summer low flows: case studies in the Sierra Nevada, California, USA, Hydrological
Processes, 28, 5048-5064, doi: 10.1002/hyp.9943, 2014. |
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