Isotopic hydrograph separation in the Hydrological Open Air Laboratory, Austria
- 1Vienna University of Technology, Institute of Hydraulic Engineering and Water Resources Management, Vienna, Austria (szeles@hydro.tuwien.ac.at)
- 2Institute of Hydrology, Slovak Academy of Sciences, Bratislava, Slovakia (Ladislav.Holko@savba.sk)
- 3University of Natural Resources and Life Sciences, Vienna, Department of Water, Atmosphere and Environment, Institute of Soil Physics and Rural Water Management, Muthgasse 18, 1190 Vienna, Austria (christine.stumpp@boku.ac.at)
- 4NES, Nuclear Engineering Seibersdorf GmbH, Seibersdorf, Austria (Stefan.Wyhlidal@nes.at)
- 5University of Natural Resources and Life Sciences, Institute of Soil Science, Stable Isotope Group, Tulln, Austria (katharina.schott@boku.ac.at)
- 6Austrian Federal Ministry of Agriculture, Forestry, Regions and Water Management, Department for Water Balance (lovrenc.pavlin@bml.gv.at)
- 7Federal Agency of Water Management, Institute for Land and Water Management Research, Petzenkirchen, Austria (peter.strauss@baw.at)
Exploring the contributions of new and old water to runoff during precipitation events in agricultural catchments is essential for understanding runoff generation, solute transport, and soil erosion. The aim of this study was to compare two isotope hydrograph separation methods in the Hydrological Open Air Laboratory (HOAL) in Austria, a 66-ha large experimental catchment dominated by agricultural land use. The classical two-component (IHS) and the ensemble isotope hydrograph separation (EIHS) methods were applied to multiple events in May-October of 2013-2018 using δ18O and δ2H. The new water contributions obtained by the IHS during peak flow were compared with the average new water fraction from the EIHS. The results showed that EIHS provided average new water fractions during peak flows (0.46 for δ18O and 0.47 for δ2H) that were close to the averages obtained by IHS (0.48 for δ18O and 0.50 for δ2H). While the EIHS may be a more robust approach compared to IHS, as it relaxes some of the assumptions of IHS and it gives a reliable average of the new water contribution, the IHS can provide useful information on the new water contribution variability for individual events.
How to cite: Széles, B., Holko, L., Parajka, J., Stumpp, C., Stockinger, M., Komma, J., Rab, G., Wyhlidal, S., Schott, K., Hogan, P., Pavlin, L., Strauss, P., Schmaltz, E., and Blöschl, G.: Isotopic hydrograph separation in the Hydrological Open Air Laboratory, Austria, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-20344, https://doi.org/10.5194/egusphere-egu24-20344, 2024.
