Articles | Volume 28, issue 15
https://doi.org/10.5194/hess-28-3519-2024
© Author(s) 2024. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
https://doi.org/10.5194/hess-28-3519-2024
© Author(s) 2024. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Research article
| 
06 Aug 2024
Research article |
| 06 Aug 2024
| 06 Aug 2024
Short high-accuracy tritium data time series for assessing groundwater mean transit times in the vadose and saturated zones of the Luxembourg Sandstone aquifer
Luxembourg Institute of Science and Technology (LIST), Belvaux, Luxembourg
Michael K. Stewart
GNS Science, Tritium & Water Dating Laboratory, Te Awa Kairangi ki Tai / Lower Hutt, New Zealand
Uwe Morgenstern
GNS Science, Tritium & Water Dating Laboratory, Te Awa Kairangi ki Tai / Lower Hutt, New Zealand
Laurent Pfister
Luxembourg Institute of Science and Technology (LIST), Belvaux, Luxembourg
Faculty of Science, Technology and Medicine, University of Luxembourg, Belval, Luxembourg
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The combined use of deuterium and tritium to determine travel time distributions in streams is an important development in catchment hydrology (Rodriguez et al., 2021). This comment, however, argues that their results do not generally invalidate the truncation hypothesis of Stewart et al. (2010) (i.e. that stable isotopes underestimate travel times through catchments), as they imply, but asserts instead that the hypothesis still applies to many other catchments.
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Jan Bondy, Jan Wienhöfer, Laurent Pfister, and Erwin Zehe
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The Budyko curve is a widely-used and simple framework to predict the mean water balance of river catchments. While many catchments are in close accordance with the Budyko curve, others show more or less significant deviations. Our study aims at better understanding the role of soil storage characteristics in the mean water balance and offsets from the Budyko curve. Soil storage proved to be a very sensitive property and potentially explains significant deviations from the curve.
Nicolas Björn Rodriguez, Laurent Pfister, Erwin Zehe, and Julian Klaus
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Different parts of water have often been used as tracers to determine the age of water in streams. The stable tracers, such as deuterium, are thought to be unable to reveal old water compared to the radioactive tracer called tritium. We used both tracers, measured in precipitation and in a stream in Luxembourg, to show that this is not necessarily true. It is, in fact, advantageous to use the two tracers together, and we recommend systematically using tritium in future studies.
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Short summary
Determining water transit times in aquifers is key to a better understanding of groundwater resources and their sustainable management. For our research, we used high-accuracy tritium data from 35 springs draining the Luxembourg Sandstone aquifer. We assessed the mean transit times of groundwater and found that water moves on average more than 10 times more slowly vertically in the vadose zone of the aquifer (~12 m yr-1) than horizontally in its saturated zone (~170 m yr-1).
Determining water transit times in aquifers is key to a better understanding of groundwater...
