Articles | Volume 25, issue 1
https://doi.org/10.5194/hess-25-401-2021
© Author(s) 2021. 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-25-401-2021
© Author(s) 2021. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
A comparison of catchment travel times and storage deduced from deuterium and tritium tracers using StorAge Selection functions
Nicolas Björn Rodriguez
CORRESPONDING AUTHOR
Catchment and Eco-hydrology Research Group, Environmental Research and Innovation Department, Luxembourg Institute of Science and Technology, Belvaux, Luxembourg
Institute of Water Resources and River Basin Management, Karlsruhe Institute of Technology, Karlsruhe, Germany
Laurent Pfister
Catchment and Eco-hydrology Research Group, Environmental Research and Innovation Department, Luxembourg Institute of Science and Technology, Belvaux, Luxembourg
Erwin Zehe
Institute of Water Resources and River Basin Management, Karlsruhe Institute of Technology, Karlsruhe, Germany
Julian Klaus
Catchment and Eco-hydrology Research Group, Environmental Research and Innovation Department, Luxembourg Institute of Science and Technology, Belvaux, Luxembourg
Related authors
No articles found.
Dan Elhanati, Erwin Zehe, Ishai Dror, and Brian Berkowitz
EGUsphere, https://doi.org/10.5194/egusphere-2025-3365, https://doi.org/10.5194/egusphere-2025-3365, 2025
This preprint is open for discussion and under review for Hydrology and Earth System Sciences (HESS).
Short summary
Short summary
Measurements of water isotopes are often used to estimate water transit time distributions and aquifer storage thickness in catchments. However, laboratory-scale measurements show that water isotopes exhibit transport behavior identical to that of inert chemical tracers rather than of pure water. The measured mean tracer and apparent mean water velocities are not necessarily equal; recognition of this inequality is critical when estimating catchment properties such as aquifer storage thickness.
Mortimer L. Bacher, Julian Klaus, Adam S. Ward, Jasmine Krause, Catalina Segura, and Clarissa Glaser
EGUsphere, https://doi.org/10.5194/egusphere-2025-1625, https://doi.org/10.5194/egusphere-2025-1625, 2025
Short summary
Short summary
Slug tracer experiments are biased toward faster flow paths, underscoring the need for tracers that reveal temporally longer timescales. We explore integrating solute tracers with naturally occurring radon to quantify flow paths of different timescales at the reach scale. Joint calibration of a transient storage model with both tracers better constrains model parameters, highlighting that this approach is critical for improving solute transport estimates in future studies.
Karl Nicolaus van Zweel, Laurent Gourdol, Jean François Iffly, Loïc Léonard, François Barnich, Laurent Pfister, Erwin Zehe, and Christophe Hissler
Earth Syst. Sci. Data, 17, 2217–2229, https://doi.org/10.5194/essd-17-2217-2025, https://doi.org/10.5194/essd-17-2217-2025, 2025
Short summary
Short summary
Our study monitored groundwater in a Luxembourg forest over a year to understand water and chemical changes. We found seasonal variations in water chemistry, influenced by rainfall and soil interactions. These data help predict environmental responses and manage water resources better. By measuring key parameters like pH and dissolved oxygen, our research provides valuable insights into groundwater behaviour and serves as a resource for future environmental studies.
Judith Nijzink, Ralf Loritz, Laurent Gourdol, Davide Zoccatelli, Jean François Iffly, and Laurent Pfister
Earth Syst. Sci. Data Discuss., https://doi.org/10.5194/essd-2024-482, https://doi.org/10.5194/essd-2024-482, 2025
Preprint under review for ESSD
Short summary
Short summary
The CAMELS-LUX dataset (Catchment Attributes and MEteorology for Large-sample Studies – LUXembourg) contains hydrologic, meteorologic and thunderstorm formation relevant atmospheric time series of 56 Luxembourgish catchments (2004–2021). These catchments are characterized by a large physiographic variety on a relatively small scale in a homogeneous climate. The dataset can be applied for (regional) hydrological analyses.
Guilhem Türk, Christoph J. Gey, Bernd R. Schöne, Marius G. Floriancic, James W. Kirchner, Loic Leonard, Laurent Gourdol, Richard Keim, and Laurent Pfister
EGUsphere, https://doi.org/10.5194/egusphere-2025-1530, https://doi.org/10.5194/egusphere-2025-1530, 2025
Short summary
Short summary
How landscape features affect water storage and release in catchments remains poorly understood. Here we used water stable isotopes in 12 streams to assess the fraction of precipitation reaching streamflow in less than 2 weeks. More recent precipitation was found when streamflow was high and the fraction was linked to the geology (i.e. high when impermeable, low when permeable). Such information is key for better anticipating streamflow responses to a changing climate.
Svenja Hoffmeister, Sibylle Kathrin Hassler, Friederike Lang, Rebekka Maier, Betserai Isaac Nyoka, and Erwin Zehe
EGUsphere, https://doi.org/10.5194/egusphere-2025-1719, https://doi.org/10.5194/egusphere-2025-1719, 2025
Short summary
Short summary
Combining trees and crops in agroforestry systems can potentially be a sustainable option for agriculture facing climate change impacts. We used methods from soil science and hydrology to assess the effect of adding gliricidia trees to maize fields, on carbon content, soil properties and water availability. Our results show a clear increase in carbon contents and effects on physical soil characteristics and water uptake and retention as a consequence of the agroforestry treatment.
Evgeny Shavelzon, Erwin Zehe, and Yaniv Edery
EGUsphere, https://doi.org/10.22541/essoar.173687429.91307309/v1, https://doi.org/10.22541/essoar.173687429.91307309/v1, 2025
Short summary
Short summary
We analyze how chemical reactions and fluid movement interact in porous materials, focusing on how water paths form in underground environments. Using a thermodynamic approach, we track energy dissipation and entropy changes to understand this process. Over time, water channels become more defined, reducing chemical mixing and energy loss. Eventually, the system stabilizes, with flow concentrated in efficient pathways, minimizing further reactions and energy use.
Tim Busker, Daniela Rodriguez Castro, Sergiy Vorogushyn, Jaap Kwadijk, Davide Zoccatelli, Rafaella Loureiro, Heather J. Murdock, Laurent Pfister, Benjamin Dewals, Kymo Slager, Annegret H. Thieken, Jan Verkade, Patrick Willems, and Jeroen C. J. H. Aerts
EGUsphere, https://doi.org/10.5194/egusphere-2025-828, https://doi.org/10.5194/egusphere-2025-828, 2025
This preprint is open for discussion and under review for Natural Hazards and Earth System Sciences (NHESS).
Short summary
Short summary
In July 2021, the Netherlands, Luxembourg, Germany, and Belgium were hit by an extreme flood event with over 200 fatalities. Our study provides, for the first time, critical insights into the operational flood early-warning systems in this entire region. Based on 13 expert interviews, we conclude that the systems strongly improved in all countries. Interviewees stressed the need for operational impact-based forecasts, but emphasized that its operational implementation is challenging.
Guilhem Türk, Christoph Johannes Gey, Bernd Reinhard Schöne, and Laurent Pfister
EGUsphere, https://doi.org/10.5194/egusphere-2024-4169, https://doi.org/10.5194/egusphere-2024-4169, 2025
Short summary
Short summary
Past stream flow dynamics can be assessed using the stable isotopes of oxygen (O16/O18) in streams and precipitation from various proxy sources. Here, we show how they are retrieved in precipitation for ~150 years using temperature records and an atmospheric circulation classification scheme. Our robust and assumption-lean approach compares to model performances in the literature, demonstrating atmospheric controls of the temperature influence on precipitation O16/O18 compositions.
Huibin Gao, Laurent Pfister, and James W. Kirchner
EGUsphere, https://doi.org/10.5194/egusphere-2025-613, https://doi.org/10.5194/egusphere-2025-613, 2025
Short summary
Short summary
Some streams respond to rainfall with flow that peaks twice: a sharp first peak followed by a broad second peak. We analyzed data from a catchment in Luxembourg to better understand the processes behind this phenomenon. Our results show that the first peak is mostly driven directly by rainfall, and the second peak is mostly driven by rain that infiltrates to groundwater. We also show that the relative importance of these two processes depends on how wet the landscape is before the rain falls.
Samuele Ceolin, Stanislaus J. Schymanski, Dagmar van Dusschoten, Robert Koller, and Julian Klaus
Biogeosciences, 22, 691–703, https://doi.org/10.5194/bg-22-691-2025, https://doi.org/10.5194/bg-22-691-2025, 2025
Short summary
Short summary
We investigated if and how roots of maize plants respond to multiple abrupt changes in soil moisture. We measured root lengths using a magnetic resonance imaging technique and calculated changes in growth rates after applying water pulses. The root growth rates increased in wetted soil layers within 48 hours and decreased in non-wetted layers, indicating fast adaptation of the root systems to moisture changes. Our findings could improve irrigation management and vegetation models.
Paolo Nasta, Günter Blöschl, Heye R. Bogena, Steffen Zacharias, Roland Baatz, Gabriëlle De Lannoy, Karsten H. Jensen, Salvatore Manfreda, Laurent Pfister, Ana M. Tarquis, Ilja van Meerveld, Marc Voltz, Yijian Zeng, William Kustas, Xin Li, Harry Vereecken, and Nunzio Romano
Hydrol. Earth Syst. Sci., 29, 465–483, https://doi.org/10.5194/hess-29-465-2025, https://doi.org/10.5194/hess-29-465-2025, 2025
Short summary
Short summary
The Unsolved Problems in Hydrology (UPH) initiative has emphasized the need to establish networks of multi-decadal hydrological observatories to tackle catchment-scale challenges on a global scale. This opinion paper provocatively discusses two endmembers of possible future hydrological observatory (HO) networks for a given hypothesized community budget: a comprehensive set of moderately instrumented observatories or, alternatively, a small number of highly instrumented supersites.
Ashish Manoj J, Ralf Loritz, Hoshin Gupta, and Erwin Zehe
Hydrol. Earth Syst. Sci. Discuss., https://doi.org/10.5194/hess-2024-375, https://doi.org/10.5194/hess-2024-375, 2024
Revised manuscript under review for HESS
Short summary
Short summary
Traditional hydrological models typically operate in a forward mode, simulating streamflow and other catchment fluxes based on precipitation input. In this study, we explored the possibility of reversing this process—inferring precipitation from streamflow data—to improve flood event modelling. We then used the generated precipitation series to run hydrological models, resulting in more accurate estimates of streamflow and soil moisture.
Svenja Hoffmeister, Rafael Bohn Reckziegel, Ben du Toit, Sibylle K. Hassler, Florian Kestel, Rebekka Maier, Jonathan P. Sheppard, and Erwin Zehe
Hydrol. Earth Syst. Sci., 28, 3963–3982, https://doi.org/10.5194/hess-28-3963-2024, https://doi.org/10.5194/hess-28-3963-2024, 2024
Short summary
Short summary
We studied a tree–crop ecosystem consisting of a blackberry field and an alder windbreak. In the water-scarce region, irrigation provides sufficient water for plant growth. The windbreak lowers the irrigation amount by reducing wind speed and therefore water transport into the atmosphere. These ecosystems could provide sustainable use of water-scarce landscapes, and we studied the complex interactions by observing several aspects (e.g. soil, nutrients, carbon assimilation, water).
Laurent Gourdol, Michael K. Stewart, Uwe Morgenstern, and Laurent Pfister
Hydrol. Earth Syst. Sci., 28, 3519–3547, https://doi.org/10.5194/hess-28-3519-2024, https://doi.org/10.5194/hess-28-3519-2024, 2024
Short summary
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).
Ginevra Fabiani, Julian Klaus, and Daniele Penna
Hydrol. Earth Syst. Sci., 28, 2683–2703, https://doi.org/10.5194/hess-28-2683-2024, https://doi.org/10.5194/hess-28-2683-2024, 2024
Short summary
Short summary
There is a limited understanding of the role that topography and climate play in tree water use. Through a cross-site comparison in Luxembourg and Italy, we investigated beech water use along slopes in different climates. Our findings indicate that in landscapes characterized by stronger hydraulic and climatic gradients there is greater spatial variation in tree physiological responses. This highlights how differing growing conditions across landscapes can lead to contrasting tree performances.
Samuel Schroers, Ulrike Scherer, and Erwin Zehe
Hydrol. Earth Syst. Sci., 27, 2535–2557, https://doi.org/10.5194/hess-27-2535-2023, https://doi.org/10.5194/hess-27-2535-2023, 2023
Short summary
Short summary
The hydrological cycle shapes our landscape. With an accelerating change of the world's climate and hydrological dynamics, concepts of evolution of natural systems become more important. In this study, we elaborated a thermodynamic framework for runoff and sediment transport and show from model results as well as from measurements during extreme events that the developed concept is useful for understanding the evolution of the system's mass, energy, and entropy fluxes.
Judith Meyer, Malte Neuper, Luca Mathias, Erwin Zehe, and Laurent Pfister
Hydrol. Earth Syst. Sci., 26, 6163–6183, https://doi.org/10.5194/hess-26-6163-2022, https://doi.org/10.5194/hess-26-6163-2022, 2022
Short summary
Short summary
We identified and analysed the major atmospheric components of rain-intense thunderstorms that can eventually lead to flash floods: high atmospheric moisture, sufficient latent instability, and weak thunderstorm cell motion. Between 1981 and 2020, atmospheric conditions became likelier to support strong thunderstorms. However, the occurrence of extreme rainfall events as well as their rainfall intensity remained mostly unchanged.
Enrico Bonanno, Günter Blöschl, and Julian Klaus
Hydrol. Earth Syst. Sci., 26, 6003–6028, https://doi.org/10.5194/hess-26-6003-2022, https://doi.org/10.5194/hess-26-6003-2022, 2022
Short summary
Short summary
There is an unclear understanding of which processes regulate the transport of water, solutes, and pollutants in streams. This is crucial since these processes control water quality in river networks. Compared to other approaches, we obtained clearer insights into the processes controlling solute transport in the investigated reach. This work highlights the risks of using uncertain results for interpreting the processes controlling water movement in streams.
Audrey Douinot, Jean François Iffly, Cyrille Tailliez, Claude Meisch, and Laurent Pfister
Hydrol. Earth Syst. Sci., 26, 5185–5206, https://doi.org/10.5194/hess-26-5185-2022, https://doi.org/10.5194/hess-26-5185-2022, 2022
Short summary
Short summary
The objective of the paper is to highlight the seasonal and singular shift of the transfer time distributions of two catchments (≅10 km2).
Based on 2 years of rainfall and discharge observations, we compare variations in the properties of TTDs with the physiographic characteristics of catchment areas and the eco-hydrological cycle. The paper eventually aims to deduce several factors conducive to particularly rapid and concentrated water transfers, which leads to flash floods.
Ralf Loritz, Maoya Bassiouni, Anke Hildebrandt, Sibylle K. Hassler, and Erwin Zehe
Hydrol. Earth Syst. Sci., 26, 4757–4771, https://doi.org/10.5194/hess-26-4757-2022, https://doi.org/10.5194/hess-26-4757-2022, 2022
Short summary
Short summary
In this study, we combine a deep-learning approach that predicts sap flow with a hydrological model to improve soil moisture and transpiration estimates at the catchment scale. Our results highlight that hybrid-model approaches, combining machine learning with physically based models, are a promising way to improve our ability to make hydrological predictions.
Alessandro Montemagno, Christophe Hissler, Victor Bense, Adriaan J. Teuling, Johanna Ziebel, and Laurent Pfister
Biogeosciences, 19, 3111–3129, https://doi.org/10.5194/bg-19-3111-2022, https://doi.org/10.5194/bg-19-3111-2022, 2022
Short summary
Short summary
We investigated the biogeochemical processes that dominate the release and retention of elements (nutrients and potentially toxic elements) during litter degradation. Our results show that toxic elements are retained in the litter, while nutrients are released in solution during the first stages of degradation. This seems linked to the capability of trees to distribute the elements between degradation-resistant and non-degradation-resistant compounds of leaves according to their chemical nature.
Samuel Schroers, Olivier Eiff, Axel Kleidon, Ulrike Scherer, Jan Wienhöfer, and Erwin Zehe
Hydrol. Earth Syst. Sci., 26, 3125–3150, https://doi.org/10.5194/hess-26-3125-2022, https://doi.org/10.5194/hess-26-3125-2022, 2022
Short summary
Short summary
In hydrology the formation of landform patterns is of special interest as changing forcings of the natural systems, such as climate or land use, will change these structures. In our study we developed a thermodynamic framework for surface runoff on hillslopes and highlight the differences of energy conversion patterns on two related spatial and temporal scales. The results indicate that surface runoff on hillslopes approaches a maximum power state.
Alexander Sternagel, Ralf Loritz, Brian Berkowitz, and Erwin Zehe
Hydrol. Earth Syst. Sci., 26, 1615–1629, https://doi.org/10.5194/hess-26-1615-2022, https://doi.org/10.5194/hess-26-1615-2022, 2022
Short summary
Short summary
We present a (physically based) Lagrangian approach to simulate diffusive mixing processes on the pore scale beyond perfectly mixed conditions. Results show the feasibility of the approach for reproducing measured mixing times and concentrations of isotopes over pore sizes and that typical shapes of breakthrough curves (normally associated with non-uniform transport in heterogeneous soils) may also occur as a result of imperfect subscale mixing in a macroscopically homogeneous soil matrix.
Erwin Zehe, Ralf Loritz, Yaniv Edery, and Brian Berkowitz
Hydrol. Earth Syst. Sci., 25, 5337–5353, https://doi.org/10.5194/hess-25-5337-2021, https://doi.org/10.5194/hess-25-5337-2021, 2021
Short summary
Short summary
This study uses the concepts of entropy and work to quantify and explain the emergence of preferential flow and transport in heterogeneous saturated porous media. We found that the downstream concentration of solutes in preferential pathways implies a downstream declining entropy in the transverse distribution of solute transport pathways. Preferential flow patterns with lower entropies emerged within media of higher heterogeneity – a stronger self-organization despite a higher randomness.
Laurent Gourdol, Rémi Clément, Jérôme Juilleret, Laurent Pfister, and Christophe Hissler
Hydrol. Earth Syst. Sci., 25, 1785–1812, https://doi.org/10.5194/hess-25-1785-2021, https://doi.org/10.5194/hess-25-1785-2021, 2021
Short summary
Short summary
Electrical resistivity tomography (ERT) is a remarkable tool for characterizing the regolith, but its use over large areas remains cumbersome due to the requirement of small electrode spacing (ES). In this study we document the issues of using oversized ESs and propose a new approach to overcome this limitation. We demonstrate that our protocol significantly improves the accuracy of ERT profiles using large ES and offers a cost-effective means for carrying out large-scale surveys.
Jan Bondy, Jan Wienhöfer, Laurent Pfister, and Erwin Zehe
Hydrol. Earth Syst. Sci. Discuss., https://doi.org/10.5194/hess-2021-174, https://doi.org/10.5194/hess-2021-174, 2021
Manuscript not accepted for further review
Short summary
Short summary
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.
Alexander Sternagel, Ralf Loritz, Julian Klaus, Brian Berkowitz, and Erwin Zehe
Hydrol. Earth Syst. Sci., 25, 1483–1508, https://doi.org/10.5194/hess-25-1483-2021, https://doi.org/10.5194/hess-25-1483-2021, 2021
Short summary
Short summary
The key innovation of the study is a method to simulate reactive solute transport in the vadose zone within a Lagrangian framework. We extend the LAST-Model with a method to account for non-linear sorption and first-order degradation processes during unsaturated transport of reactive substances in the matrix and macropores. Model evaluations using bromide and pesticide data from irrigation experiments under different flow conditions on various timescales show the feasibility of the method.
Samuel Schroers, Olivier Eiff, Axel Kleidon, Jan Wienhöfer, and Erwin Zehe
Hydrol. Earth Syst. Sci. Discuss., https://doi.org/10.5194/hess-2021-79, https://doi.org/10.5194/hess-2021-79, 2021
Manuscript not accepted for further review
Short summary
Short summary
In this study we ask the basic question why surface runoff forms drainage networks and confluences at all and how structural macro form and micro topography is a result of thermodynamic laws. We find that on a macro level hillslopes should tend from negative exponential towards exponential forms and that on a micro level the formation of rills goes hand in hand with drainage network formation of river basins. We hypothesize that we can learn more about erosion processes if we extend this theory.
Ralf Loritz, Markus Hrachowitz, Malte Neuper, and Erwin Zehe
Hydrol. Earth Syst. Sci., 25, 147–167, https://doi.org/10.5194/hess-25-147-2021, https://doi.org/10.5194/hess-25-147-2021, 2021
Short summary
Short summary
This study investigates the role and value of distributed rainfall in the runoff generation of a mesoscale catchment. We compare the performance of different hydrological models at different periods and show that a distributed model driven by distributed rainfall yields improved performances only during certain periods. We then step beyond this finding and develop a spatially adaptive model that is capable of dynamically adjusting its spatial model structure in time.
Conrad Jackisch, Samuel Knoblauch, Theresa Blume, Erwin Zehe, and Sibylle K. Hassler
Biogeosciences, 17, 5787–5808, https://doi.org/10.5194/bg-17-5787-2020, https://doi.org/10.5194/bg-17-5787-2020, 2020
Short summary
Short summary
We developed software to calculate the root water uptake (RWU) of beech tree roots from soil moisture dynamics. We present our approach and compare RWU to measured sap flow in the tree stem. The study relates to two sites that are similar in topography and weather but with contrasting soils. While sap flow is very similar between the two sites, the RWU is different. This suggests that soil characteristics have substantial influence. Our easy-to-implement RWU estimate may help further studies.
Jasper Foets, Carlos E. Wetzel, Núria Martínez-Carreras, Adriaan J. Teuling, Jean-François Iffly, and Laurent Pfister
Hydrol. Earth Syst. Sci., 24, 4709–4725, https://doi.org/10.5194/hess-24-4709-2020, https://doi.org/10.5194/hess-24-4709-2020, 2020
Short summary
Short summary
Diatoms (microscopic algae) are regarded as useful tracers in catchment hydrology. However, diatom analysis is labour-intensive; therefore, only a limited number of samples can be analysed. To reduce this number, we explored the potential for a time-integrated mass-flux sampler to provide a representative sample of the diatom assemblage for a whole storm run-off event. Our results indicate that the Phillips sampler did indeed sample representative communities during two of the three events.
Uwe Ehret, Rik van Pruijssen, Marina Bortoli, Ralf Loritz, Elnaz Azmi, and Erwin Zehe
Hydrol. Earth Syst. Sci., 24, 4389–4411, https://doi.org/10.5194/hess-24-4389-2020, https://doi.org/10.5194/hess-24-4389-2020, 2020
Short summary
Short summary
In this paper we propose adaptive clustering as a new method for reducing the computational efforts of distributed modelling. It consists of identifying similar-acting model elements during the runtime, clustering them, running the model for just a few representatives per cluster, and mapping their results to the remaining model elements in the cluster. With the example of a hydrological model, we show that this saves considerable computation time, while largely maintaining the output quality.
Cited articles
Angermann, L., Jackisch, C., Allroggen, N., Sprenger, M., Zehe, E., Tronicke,
J., Weiler, M., and Blume, T.: Form and function in hillslope hydrology:
characterization of subsurface flow based on response observations, Hydrol.
Earth Syst. Sci., 21, 3727–3748, https://doi.org/10.5194/hess-21-3727-2017, 2017. a, b, c
Antonelli, M., Glaser, B., Teuling, A. J., Klaus, J., and Pfister, L.:
Saturated areas through the lens: 1. Spatio-temporal variability of surface
saturation documented through thermal infrared imagery, Hydrol. Process., 34, 1310–1332, https://doi.org/10.1002/hyp.13698, 2020a. a
Antonelli, M., Glaser, B., Teuling, A J., Klaus, J., and Pfister, L.:
Saturated areas through the lens: 2. Spatio-temporal variability of
streamflow generation and its relationship with surface saturation, Hydrol. Process, 34, 1333–1349, https://doi.org/10.1002/hyp.13607, 2020b. a
Bajjali, W.: Spatial variability of environmental isotope and chemical content of precipitation in Jordan and evidence of slight change in climate, Appl. Water Sci., 2, 271–283, https://doi.org/10.1007/s13201-012-0046-1, 2012. a
Begemann, F. and Libby, W.: Continental water balance, ground water inventory
and storage times, surface ocean mixing rates and world-wide water circulation patterns from cosmic-ray and bomb tritium, Geochim. Cosmochim. Ac., 12, 277–296, https://doi.org/10.1016/0016-7037(57)90040-6, 1957. a
Benettin, P. and Bertuzzo, E.: tran-SAS v1.0: a numerical model to
compute catchment-scale hydrologic transport using StorAge Selection
functions, Geosci. Model Dev., 11, 1627–1639, https://doi.org/10.5194/gmd-11-1627-2018, 2018. a
Benettin, P., Bailey, S. W., Campbell, J. L., Green, M. B., Rinaldo, A.,
Likens, G. E., McGuire, K. J., and Botter, G.: Linking water age and solute
dynamics in streamflow at the Hubbard Brook Experimental Forest, NH, USA,
Water Resour. Res., 51, 9256–9272, https://doi.org/10.1002/2015WR017552, 2015a. a, b, c, d
Benettin, P., Rinaldo, A., and Botter, G.: Tracking residence times in
hydrological systems: forward and backward formulations, Hydrol. Process., 29, 5203–5213, https://doi.org/10.1002/hyp.10513, 2015b. a
Benettin, P., Bailey, S. W., Rinaldo, A., Likens, G. E., McGuire, K. J., and
Botter, G.: Young runoff fractions control streamwater age and solute
concentration dynamics, Hydrol. Process., 31, 2982–2986,
https://doi.org/10.1002/hyp.11243, 2017a. a
Benettin, P., Soulsby, C., Birkel, C., Tetzlaff, D., Botter, G., and Rinaldo,
A.: Using SAS functions and high-resolution isotope data to unravel travel
time distributions in headwater catchments, Water Resour. Res., 53, 1864–1878, https://doi.org/10.1002/2016WR020117, 2017b. a, b
Berman, E. S. F., Gupta, M., Gabrielli, C., Garland, T., and McDonnell, J. J.: High-frequency field-deployable isotope analyzer for hydrological
applications, Water Resour. Res., 45, W10201, https://doi.org/10.1029/2009WR008265, 2009. a
Berry, Z. C., Evaristo, J., Moore, G., Poca, M., Steppe, K., Verrot, L.,
Asbjornsen, H., Borma, L. S., Bretfeld, M., Hervé-Fernández, P., Seyfried, M., Schwendenmann, L., Sinacore, K., De Wispelaere, L., and McDonnell, J.: The two water worlds hypothesis: Addressing multiple working hypotheses and proposing a way forward, Ecohydrology, 11, e1843, https://doi.org/10.1002/eco.1843, 2018. a
Bethke, C. M. and Johnson, T. M.: Groundwater Age and Groundwater Age Dating,
Annu. Rev. Earth Planet. Sci., 36, 121–152, https://doi.org/10.1146/annurev.earth.36.031207.124210, 2008. a
Beven, K. and Binley, A.: The future of distributed models: Model calibration
and uncertainty prediction, Hydrol. Process., 6, 279–298, https://doi.org/10.1002/hyp.3360060305, 1992. a, b
Birkel, C., Soulsby, C., and Tetzlaff, D.: Modelling catchment-scale water
storage dynamics: reconciling dynamic storage with tracer-inferred passive
storage, Hydrol. Process., 25, 3924–3936, https://doi.org/10.1002/hyp.8201, 2011. a, b
Birkel, C., Soulsby, C., and Tetzlaff, D.: Conceptual modelling to assess how
the interplay of hydrological connectivity, catchment storage and tracer
dynamics controls nonstationary water age estimates, Hydrol. Process., 29, 2956–2969, https://doi.org/10.1002/hyp.10414, 2015. a, b
Botter, G., Bertuzzo, E., and Rinaldo, A.: Catchment residence and travel time distributions: The master equation, Geophys. Res. Lett., 38, L11403, https://doi.org/10.1029/2011GL047666, 2011. a, b
Brooks, J. R., Barnard, H. R., Coulombe, R., and McDonnell, J. J.: Ecohydrologic separation of water between trees and streams in a Mediterranean climate, Nat. Geosci., 3, 100–104, https://doi.org/10.1038/ngeo722, 2010. a
Buttafuoco, G., Caloiero, T., and Coscarelli, R.: Spatial uncertainty assessment in modelling reference evapotranspiration at regional scale, Hydrol. Earth Syst. Sci., 14, 2319–2327, https://doi.org/10.5194/hess-14-2319-2010, 2010. a
Buttle, J.: Isotope hydrograph separations and rapid delivery of pre-event
water from drainage basins, Prog. Phys. Geogr., 18, 16–41, https://doi.org/10.1177/030913339401800102, 1994. a
Buzacott, A. J., van der Velde, Y., Keitel, C., and Vervoort, R. W.:
Constraining water age dynamics in a south-eastern Australian catchment using
an age-ranked storage and stable isotope approach, Hydrol. Process., 34, 4384–4403, https://doi.org/10.1002/hyp.13880, 2020. a
Carrer, G. E., Klaus, J., and Pfister, L.: Assessing the Catchment Storage
Function Through a Dual-Storage Concept, Water Resour. Res., 55, 476–494, https://doi.org/10.1029/2018WR022856, 2019. a, b, c
Cartwright, I. and Morgenstern, U.: Contrasting transit times of water from
peatlands and eucalypt forests in the Australian Alps determined by tritium:
implications for vulnerability and the source of water in upland catchments,
Hydrol. Earth Syst. Sci., 20, 4757–4773, https://doi.org/10.5194/hess-20-4757-2016, 2016. a
Criss, R. E. and Winston, W. E.: Do Nash values have value? Discussion and
alternate proposals, Hydrol. Process., 22, 2723–2725, https://doi.org/10.1002/hyp.7072, 2008. a
Crouzet, E., Hubert, P., Olive, P., Siwertz, E., and Marce, A.: Le tritium dans les mesures d'hydrologie de surface. Determination experimentale du
coefficient de ruissellement, J. Hydrol., 11, 217–229,
https://doi.org/10.1016/0022-1694(70)90063-6, 1970. a, b
Delsman, J. R., Essink, G. H. P. O., Beven, K. J., and Stuyfzand, P. J.:
Uncertainty estimation of end-member mixing using generalized likelihood
uncertainty estimation (GLUE), applied in a lowland catchment, Water Resour. Res., 49, 4792–4806, https://doi.org/10.1002/wrcr.20341, 2013. a
Devell, L.: Measurements of the Self-diffusion of Water in Pure Water, H2O-D2O Mixtures and Solutions of Electrolytes, Acta Chem. Scand., 16, 2177–2188, https://doi.org/10.3891/acta.chem.scand.16-2177, 1962. a
Dinçer, T., Payne, B. R., Florkowski, T., Martinec, J., and Tongiorgi, E.: Snowmelt runoff from measurements of tritium and oxygen-18, Water Resour. Res., 6, 110–124, https://doi.org/10.1029/WR006i001p00110, 1970. a, b, c, d
Doherty, J. and Johnston, J. M.: Methodologies For Calibration And Predictive Analysis Of A Watershed Model, J. Am. Water Resour. Assoc., 39, 251–265, https://doi.org/10.1111/j.1752-1688.2003.tb04381.x, 2003. a
Dralle, D. N., Hahm, W. J., Rempe, D. M., Karst, N. J., Thompson, S. E., and
Dietrich, W. E.: Quantification of the seasonal hillslope water storage that
does not drive streamflow, Hydrol. Process., 32, 1978–1992, https://doi.org/10.1002/hyp.11627, 2018. a
Dubbert, M., Caldeira, M. C., Dubbert, D., and Werner, C.: A pool-weighted
perspective on the two-water-worlds hypothesis, New Phytol., 222, 1271–1283, https://doi.org/10.1111/nph.15670, 2019. a
Duvert, C., Stewart, M. K., Cendón, D. I., and Raiber, M.: Time series of
tritium, stable isotopes and chloride reveal short-term variations in
groundwater contribution to a stream, Hydrol. Earth Syst. Sci., 20, 257–277, https://doi.org/10.5194/hess-20-257-2016, 2016. a, b
Ehret, U. and Zehe, E.: Series distance – an intuitive metric to quantify
hydrograph similarity in terms of occurrence, amplitude and timing of
hydrological events, Hydrol. Earth Syst. Sci., 15, 877–896,
https://doi.org/10.5194/hess-15-877-2011, 2011. a
Eriksson, E.: The Possible Use of Tritium' for Estimating Groundwater Storage, Tellus, 10, 472–478, https://doi.org/10.1111/j.2153-3490.1958.tb02035.x, 1958. a
Etter, S., Strobl, B., Seibert, J., and van Meerveld, H. J. I.: Value of
uncertain streamflow observations for hydrological modelling, Hydrol. Earth Syst. Sci., 22, 5243–5257, https://doi.org/10.5194/hess-22-5243-2018, 2018. a
Fenicia, F., Wrede, S., Kavetski, D., Pfister, L., Hoffmann, L., Savenije, H.
H. G., and McDonnell, J. J.: Assessing the impact of mixing assumptions on
the estimation of streamwater mean residence time, Hydrol. Process., 24, 1730–1741, https://doi.org/10.1002/hyp.7595, 2010. a, b, c
Fenicia, F., Kavetski, D., Savenije, H. H. G., Clark, M. P., Schoups, G.,
Pfister, L., and Freer, J.: Catchment properties, function, and conceptual
model representation: is there a correspondence?, Hydrol. Process., 28,
2451–2467, https://doi.org/10.1002/hyp.9726, 2014. a
Fenicia, F., Kavetski, D., Savenije, H. H. G., and Pfister, L.: From spatially variable streamflow to distributed hydrological models: Analysis of key modeling decisions, Water Resour. Res., 52, 954–989,
https://doi.org/10.1002/2015WR017398, 2016. a
Gabrielli, C. P., Morgenstern, U., Stewart, M. K., and McDonnell, J. J.:
Contrasting Groundwater and Streamflow Ages at the Maimai Watershed, Water
Resour. Res., 54, 3937–3957, https://doi.org/10.1029/2017WR021825, 2018. a
Gallart, F., Roig-Planasdemunt, M., Stewart, M. K., Llorens, P., Morgenstern,
U., Stichler, W., Pfister, L., and Latron, J.: A GLUE-based uncertainty
assessment framework for tritium-inferred transit time estimations under
baseflow conditions, Hydrol. Process., 30, 4741–4760, https://doi.org/10.1002/hyp.10991, 2016. a, b, c, d
Glaser, B., Klaus, J., Frei, S., Frentress, J., Pfister, L., and Hopp, L.: On
the value of surface saturated area dynamics mapped with thermal infrared
imagery for modeling the hillslope-riparian-stream continuum, Water Resour.
Res., 52, 8317–8342, https://doi.org/10.1002/2015WR018414, 2016. a, b, c, d, e
Glaser, B., Antonelli, M., Chini, M., Pfister, L., and Klaus, J.: Technical
note: Mapping surface-saturation dynamics with thermal infrared imagery, Hydrol. Earth Syst. Sci., 22, 5987–6003,
https://doi.org/10.5194/hess-22-5987-2018, 2018. a
Glaser, B., Jackisch, C., Hopp, L., and Klaus, J.: How meaningful are plot-scale observations and simulations of preferential flow for catchment
models?, Vadose Zone J., 18, 1–18, https://doi.org/10.2136/vzj2018.08.0146, 2019. a, b, c
Glaser, B., Antonelli, M., Hopp, L., and Klaus, J.: Intra-catchment variability of surface saturation – insights from physically based simulations in comparison with biweekly thermal infrared image observations, Hydrol. Earth Syst. Sci., 24, 1393–1413, https://doi.org/10.5194/hess-24-1393-2020, 2020. a, b, c
Graham, C. B., van Verseveld, W., Barnard, H. R., and McDonnell, J. J.:
Estimating the deep seepage component of the hillslope and catchment water
balance within a measurement uncertainty framework, Hydrol. Process., 24, 3631–3647, https://doi.org/10.1002/hyp.7788, 2010. a
Gupta, P., Noone, D., Galewsky, J., Sweeney, C., and Vaughn, B. H.:
Demonstration of high-precision continuous measurements of water vapor
isotopologues in laboratory and remote field deployments using
wavelength-scanned cavity ring-down spectroscopy (WS-CRDS) technology, Rapid
Commun. Mass Spectrom., 23, 2534–2542, https://doi.org/10.1002/rcm.4100, 2009. a
Gusyev, M. A., Toews, M., Morgenstern, U., Stewart, M., White, P., Daughney,
C., and Hadfield, J.: Calibration of a transient transport model to tritium
data in streams and simulation of groundwater ages in the western Lake Taupo
catchment, New Zealand, Hydrol. Earth Syst. Sci., 17, 1217–1227,
https://doi.org/10.5194/hess-17-1217-2013, 2013. a
Halder, J., Terzer, S., Wassenaar, L. I., Araguás-Araguás, L. J., and
Aggarwal, P. K.: The Global Network of Isotopes in Rivers (GNIR): integration
of water isotopes in watershed observation and riverine research, Hydrol. Earth Syst. Sci., 19, 3419–3431, https://doi.org/10.5194/hess-19-3419-2015, 2015. a
Harman, C. J.: Time-variable transit time distributions and transport: Theory
and application to storage-dependent transport of chloride in a watershed,
Water Resour. Res., 51, 1–30, https://doi.org/10.1002/2014WR015707, 2015. a, b, c
Heidbuechel, I., Troch, P. A., Lyon, S. W., and Weiler, M.: The master transit time distribution of variable flow systems, Water Resour. Res., 48, W06520, https://doi.org/10.1029/2011WR011293, 2012. a
Helton, J. and Davis, F.: Latin hypercube sampling and the propagation of
uncertainty in analyses of complex systems, Reliabil. Eng. Syst. Saf., 81, 23–69, https://doi.org/10.1016/S0951-8320(03)00058-9, 2003. a, b
Herbstritt, B., Gralher, B., and Weiler, M.: Continuous in situ measurements of stable isotopes in liquid water, Water Resour. Res., 48, W03601, https://doi.org/10.1029/2011WR011369, 2012. a
Herbstritt, B., Gralher, B., and Weiler, M.: Continuous, near-real-time
observations of water stable isotope ratios during rainfall and throughfall
events, Hydrol. Earth Syst. Sci., 23, 3007–3019, https://doi.org/10.5194/hess-23-3007-2019, 2019. a
Hissler, C., Martínez-Carreras, N., Barnich, F., Gourdol, L., Iffly, J. F., Juilleret, J., Klaus, J., and Pfister, L.: The Weierbach experimental catchment in Luxembourg: a decade of critical zone monitoring in a temperate forest – from hydrological investigations to ecohydrological perspectives, Version 1.0, Zenodo, https://doi.org/10.5281/zenodo.4061554, 2020. a
Hrachowitz, M., Soulsby, C., Tetzlaff, D., and Malcolm, I. A.: Sensitivity of
mean transit time estimates to model conditioning and data availability, Hydrol. Process., 25, 980–990, https://doi.org/10.1002/hyp.7922, 2011. a
Hrachowitz, M., Savenije, H., Bogaard, T. A., Tetzlaff, D., and Soulsby, C.:
What can flux tracking teach us about water age distribution patterns and
their temporal dynamics?, Hydrol. Earth Syst. Sci., 17, 533–564, https://doi.org/10.5194/hess-17-533-2013, 2013. a, b
Hrachowitz, M., Benettin, P., Breukelen, B. M. V., Fovet, O., Howden, N. J. K., Ruiz, L., Velde, Y. V. D., and Wade, A. J.: Transit times – the link
between hydrology and water quality at the catchment scale, Wiley Interdisciplin. Rev.: Water, 3, 629–657, https://doi.org/10.1002/wat2.1155, 2016. a
Hubert, P., Marin, E., Meybeck, M., Olive, P., and Siwertz, E.: Aspects
Hydrologiques, Géochimiques et Sédimentologique de la Crue
Exceptionnelle de la Dranse du Chablais du 22 Septembre 1968, in: Archives des Sciences, volume 22, fascicule 1, edited by: la Société de Physique et d'Histoire Naturelle de Genève, Geneva, 581–604, 1969. a, b, c
IAEA: Global Network of Isotopes in Rivers, The GNIR Database, available at:
https://nucleus.iaea.org/wiser (last access: 24 January 2021), 2019. a
Jackisch, C., Angermann, L., Allroggen, N., Sprenger, M., Blume, T., Tronicke, J., and Zehe, E.: Form and function in hillslope hydrology: in situ imaging and characterization of flow-relevant structures, Hydrol. Earth Syst.
Sci., 21, 3749–3775, https://doi.org/10.5194/hess-21-3749-2017, 2017. a
Juilleret, J., Dondeyne, S., Vancampenhout, K., Deckers, J., and Hissler, C.:
Mind the gap: A classification system for integrating the subsolum into soil
surveys, Geoderma, 264, 332–339, 2016. a
Keim, R. F., Kendall, C., and Jefferson, A.: The Expanding Utility of Laser
Spectroscopy, Eos Trans. Am. Geophys. Union, 95, 144–144,
https://doi.org/10.1002/2014EO170007, 2014. a
Kendall, C. and McDonnell, J. J.: Isotope tracers in catchment hydrology,
Elsevier, Amsterdam, https://doi.org/10.1016/B978-0-444-81546-0.50001-X, 1998. a, b
Kirchner, J. W.: A double paradox in catchment hydrology and geochemistry,
Hydrol. Process., 17, 871–874, https://doi.org/10.1002/hyp.5108, 2003. a
Kirchner, J. W.: Aggregation in environmental systems – Part 1: Seasonal
tracer cycles quantify young water fractions, but not mean transit times, in
spatially heterogeneous catchments, Hydrol. Earth Syst. Sci., 20, 279–297, https://doi.org/10.5194/hess-20-279-2016, 2016. a, b
Klaus, J. and McDonnell, J.: Hydrograph separation using stable isotopes:
Review and evaluation, J. Hydrol., 505, 47–64, https://doi.org/10.1016/j.jhydrol.2013.09.006, 2013. a, b
Klaus, J. and Zehe, E.: Modelling rapid flow response of a tile-drained field
site using a 2D physically based model: assessment of `equifinal' model
setups, Hydrol. Process., 24, 1595–1609, https://doi.org/10.1002/hyp.7687, 2010. a, b
Klaus, J., Chun, K. P., McGuire, K. J., and McDonnell, J. J.: Temporal dynamics of catchment transit times from stable isotope data, Water Resour.
Res., 51, 4208–4223, https://doi.org/10.1002/2014WR016247, 2015a. a
Koehler, G. and Wassenaar, L. I.: Realtime Stable Isotope Monitoring of Natural Waters by Parallel-Flow Laser Spectroscopy, Anal. Chem., 83, 913–919, https://doi.org/10.1021/ac102584q, pMID: 21214188, 2011. a
Kreft, A. and Zuber, A.: On the physical meaning of the dispersion equation and its solutions for different initial and boundary conditions, Chem. Eng. Sci. 33, 1471–1480, https://doi.org/10.1016/0009-2509(78)85196-3, 1978. a
Lis, G., Wassenaar, L. I., and Hendry, M. J.: High-Precision Laser Spectroscopy D∕H and 18O∕16O Measurements of Microliter Natural Water Samples, Anal. Chem., 80, 287–293, https://doi.org/10.1021/ac701716q, 2008. a
Loritz, R., Gupta, H., Jackisch, C., Westhoff, M., Kleidon, A., Ehret, U., and Zehe, E.: On the dynamic nature of hydrological similarity, Hydrol. Earth Syst. Sci., 22, 3663–3684, https://doi.org/10.5194/hess-22-3663-2018, 2018. a
Loritz, R., Kleidon, A., Jackisch, C., Westhoff, M., Ehret, U., Gupta, H., and Zehe, E.: A topographic index explaining hydrological similarity by
accounting for the joint controls of runoff formation, Hydrol. Earth Syst. Sci., 23, 3807–3821, https://doi.org/10.5194/hess-23-3807-2019, 2019. a
Maher, K.: The role of fluid residence time and topographic scales in
determining chemical fluxes from landscapes, Earth Planet. Sc. Lett., 312, 48–58, https://doi.org/10.1016/j.epsl.2011.09.040, 2011. a
Małoszewski, P. and Zuber, A.: Determining the turnover time of groundwater systems with the aid of environmental tracers: 1. Models and their applicability, J. Hydrol., 57, 207–231,
https://doi.org/10.1016/0022-1694(82)90147-0, 1982. a, b, c, d
Małoszewski, P. and Zuber, A.: Principles and practice of calibration and validation of mathematical models for the interpretation of environmental tracer data in aquifers, Adv. Water Resour., 16, 173–190,
https://doi.org/10.1016/0309-1708(93)90036-F, 1993. a
Małoszewski, P., Rauert, W., Stichler, W., and Herrmann, A.: Application of flow models in an alpine catchment area using tritium and deuterium data, J. Hydrol., 66, 319–330, https://doi.org/10.1016/0022-1694(83)90193-2, 1983. a, b, c
Martinec, J.: Subsurface flow from snowmelt traced by tritium, Water Resour. Res., 11, 496–498, https://doi.org/10.1029/WR011i003p00496, 1975. a
Martínez-Carreras, N., Wetzel, C. E., Frentress, J., Ector, L., McDonnell, J. J., Hoffmann, L., and Pfister, L.: Hydrological connectivity inferred from diatom transport through the riparian-stream system, Hydrol. Earth Syst. Sci., 19, 3133–3151, https://doi.org/10.5194/hess-19-3133-2015, 2015. a, b, c
Martínez-Carreras, N., Hissler, C., Gourdol, L., Klaus, J., Juilleret, J., Iffly, J. F., and Pfister, L.: Storage controls on the generation of double peak hydrographs in a forested headwater catchment, J. Hydrol., 543, 255–269, https://doi.org/10.1016/j.jhydrol.2016.10.004, 2016. a, b, c, d
McCutcheon, R. J., McNamara, J. P., Kohn, M. J., and Evans, S. L.: An
evaluation of the ecohydrological separation hypothesis in a semiarid catchment, Hydrol. Process., 31, 783–799, https://doi.org/10.1002/hyp.11052, 2017. a
McDonnell, J. J.: The two water worlds hypothesis: ecohydrological separation
of water between streams and trees?, Wiley Interdisciplin. Rev.: Water, 1, 323–329, https://doi.org/10.1002/wat2.1027, 2014. a
McDonnell, J. J. and Beven, K. J.: Debates on Water Resources: The future of
hydrological sciences: A (common) path forward? A call to action aimed at
understanding velocities, celerities and residence time distributions of the
headwater hydrograph, Water Resour. Res., 50, 5342–5350, https://doi.org/10.1002/2013WR015141, 2014. a
McGuire, K. J. and McDonnell, J. J.: A review and evaluation of catchment
transit time modeling, J. Hydrol., 330, 543–563, https://doi.org/10.1016/j.jhydrol.2006.04.020, 2006. a, b, c, d
McGuire, K. J., McDonnell, J. J., Weiler, M., Kendall, C., McGlynn, B. L.,
Welker, J. M., and Seibert, J.: The role of topography on catchment-scale
water residence time, Water Resour. Res., 41, W05002, https://doi.org/10.1029/2004WR003657, 2005. a
McMahon, T. A., Peel, M. C., Lowe, L., Srikanthan, R., and McVicar, T. R.:
Estimating actual, potential, reference crop and pan evaporation using
standard meteorological data: a pragmatic synthesis, Hydrol. Earth Syst. Sci., 17, 1331–1363, https://doi.org/10.5194/hess-17-1331-2013, 2013. a
McMillan, H., Krueger, T., and Freer, J.: Benchmarking observational
uncertainties for hydrology: rainfall, river discharge and water quality,
Hydrol. Process., 26, 4078–4111, https://doi.org/10.1002/hyp.9384, 2012. a
Michelsen, N., Laube, G., Friesen, J., Weise, S. M., Bait Said, A. B. A., and
Müller, T.: Technical note: A microcontroller-based automatic rain sampler for stable isotope studies, Hydrol. Earth Syst. Sci., 23, 2637–2645, https://doi.org/10.5194/hess-23-2637-2019, 2019. a
Moragues-Quiroga, C., Juilleret, J., Gourdol, L., Pelt, E., Perrone, T.,
Aubert, A., Morvan, G., Chabaux, F., Legout, A., Stille, P., and Hissler, C.:
Genesis and evolution of regoliths: Evidence from trace and major elements
and Sr-Nd-Pb-U isotopes, Catena, 149, 185–198, https://doi.org/10.1016/j.catena.2016.09.015, 2017. a
Morgenstern, U. and Taylor, C. B.: Ultra low-level tritium measurement using
electrolytic enrichment and LSC, Isotop. Environ. Health Stud., 45, 96–117, https://doi.org/10.1080/10256010902931194, 2009. a, b
Munksgaard, N. C., Wurster, C. M., and Bird, M. I.: Continuous analysis of
δ18O and δD values of water by diffusion sampling cavity ring-down spectrometry: a novel sampling device for unattended field monitoring of precipitation, ground and surface waters, Rapid Commun. Mass Spectrom., 25, 3706–3712, https://doi.org/10.1002/rcm.5282, 2011. a
Östlund, G. H.: Hurricane Tritium I: Preliminary Results on Hilda 1964 and Betsy 1965, AGU – American Geophysical Union, available at: https://agupubs.onlinelibrary.wiley.com/doi/book/10.1029/GM011 (last access: 24 January 2021), 2013. a
Palcsu, L., Morgenstern, U., Sültenfuss, J., Koltai, G., László,
E., Temovski, M., Major, Z., Nagy, J. T., Papp, L., Varlam, C., Faurescu, I.,
Túri, M., Rinyu, L., Czuppon, G., Bottyán, E., and Jull, A. J. T.:
Modulation of Cosmogenic Tritium in Meteoric Precipitation by the 11-year
Cycle of Solar Magnetic Field Activity, Scient. Rep., 8, 12813,
https://doi.org/10.1038/s41598-018-31208-9, 2018. a
Pangle, L. A., Klaus, J., Berman, E. S. F., Gupta, M., and McDonnell, J. J.: A new multisource and high-frequency approach to measuring δ2H and δ18O in hydrological field studies, Water Resour. Res., 49, 7797–7803, https://doi.org/10.1002/2013WR013743, 2013. a, b
Parsekian, A. D., Singha, K., Minsley, B. J., Holbrook, W. S., and Slater, L.: Multiscale geophysical imaging of the critical zone, Rev. Geophys., 53, 1–26, https://doi.org/10.1002/2014RG000465, 2015. a
Pfister, L., Martínez-Carreras, N., Hissler, C., Klaus, J., Carrer, G. E., Stewart, M. K., and McDonnell, J. J.: Bedrock geology controls on catchment storage, mixing, and release: A comparative analysis of 16 nested catchments, Hydrol. Process., 31, 1828–1845, https://doi.org/10.1002/hyp.11134, 2017. a, b, c, d, e, f, g
Pfister, L., Thielen, F., Deloule, E., Valle, N., Lentzen, E., Grave, C.,
Beisel, J.-N., and McDonnell, J. J.: Freshwater pearl mussels as a stream
water stable isotope recorder, Ecohydrology, 11, e2007, https://doi.org/10.1002/eco.2007, 2018. a
Pfister, L., Grave, C., Beisel, J.-N., and McDonnell, J. J.: A global
assessment of freshwater mollusk shell oxygen isotope signatures and their
relation to precipitation and stream water, Scient. Rep., 9, 4312,
https://doi.org/10.1038/s41598-019-40369-0, 2019. a
Pool, S., Viviroli, D., and Seibert, J.: Prediction of hydrographs and
flow-duration curves in almost ungauged catchments: Which runoff measurements
are most informative for model calibration?, J. Hydrol., 554, 613–622, https://doi.org/10.1016/j.jhydrol.2017.09.037, 2017. a
Rank, D., Wyhlidal, S., Schott, K., Weigand, S., and Oblin, A.: Temporal and
spatial distribution of isotopes in river water in Central Europe: 50 years
experience with the Austrian network of isotopes in rivers, Isotop. Environ. Health Stud., 54, 115–136, https://doi.org/10.1080/10256016.2017.1383906, 2018. a, b
Rinaldo, A. and Marani, A.: Basin scale-model of solute transport, Water Resour. Res., 23, 2107–2118, https://doi.org/10.1029/WR023i011p02107, 1987. a
Rinaldo, A., Benettin, P., Harman, C. J., Hrachowitz, M., McGuire, K. J.,
van der Velde, Y., Bertuzzo, E., and Botter, G.: Storage selection functions:
A coherent framework for quantifying how catchments store and release water
and solutes, Water Resour. Res., 51, 4840–4847, https://doi.org/10.1002/2015WR017273, 2015. a
Rodriguez, N. B.: Composite StorAge Selection based model of deuterium and tritium transport in the Weierbach catchment, available at: https://git.list.lu/catchment-eco-hydro/composite_sas_model_2h_3h_weierbach, last access: 23 January 2021. a
Rodriguez, N. B., McGuire, K. J., and Klaus, J.: Time-Varying Storage-Water Age Relationships in a Catchment With a Mediterranean Climate, Water Resour.
Res., 54, 3988–4008, https://doi.org/10.1029/2017wr021964, 2018. a, b
Rodriguez, N. B., Benettin, P., and Klaus, J.: Multimodal water age
distributions and the challenge of complex hydrological landscapes, Hydrol. Process., 34, 2707–2724, https://doi.org/10.1002/hyp.13770, 2020. a, b
Różański, K., Froehlich, K., and Mook, W. G.: Environmental Isotopes in the Hydrological Cycle, Principles and Applications, in: Volume III: Surface water, IAEA and UNESCO, Paris, 2001. a
Scaini, A., Audebert, M., Hissler, C., Fenicia, F., Gourdol, L., Pfister, L.,
and Beven, K. J.: Velocity and celerity dynamics at plot scale inferred from
artificial tracing experiments and time-lapse ERT, J. Hydrol., 546, 28–43, https://doi.org/10.1016/j.jhydrol.2016.12.035, 2017. a, b, c
Scaini, A., Hissler, C., Fenicia, F., Juilleret, J., Iffly, J. F., Pfister, L., and Beven, K.: Hillslope response to sprinkling and natural rainfall using velocity and celerity estimates in a slate-bedrock catchment, J. Hydrol., 558, 366–379, https://doi.org/10.1016/j.jhydrol.2017.12.011, 2018. a, b, c
Schaefli, B. and Gupta, H. V.: Do Nash values have value?, Hydrol. Process., 21, 2075–2080, https://doi.org/10.1002/hyp.6825, 2007. a, b
Schmidt, A., Frank, G., Stichler, W., Duester, L., Steinkopff, T., and Stumpp, C.: Overview of tritium records from precipitation and surface waters in Germany, Hydrol. Process., 34, 1489–1493, https://doi.org/10.1002/hyp.13691, 2020. a
Schoups, G. and Vrugt, J. A.: A formal likelihood function for parameter and
predictive inference of hydrologic models with correlated, heteroscedastic,
and non-Gaussian errors, Water Resour. Res., 46, W10531, https://doi.org/10.1029/2009WR008933, 2010. a
Schwab, M. P., Klaus, J., Pfister, L., and Weiler, M.: Diel fluctuations of
viscosity-driven riparian inflow affect streamflow DOC concentration,
Biogeosciences, 15, 2177–2188, https://doi.org/10.5194/bg-15-2177-2018, 2018. a
Seibert, J.: On the need for benchmarks in hydrological modelling, Hydrol. Process., 15, 1063–1064, https://doi.org/10.1002/hyp.446, 2001. a
Seibert, S. P., Ehret, U., and Zehe, E.: Disentangling timing and amplitude
errors in streamflow simulations, Hydrol. Earth Syst. Sci., 20, 3745–3763, https://doi.org/10.5194/hess-20-3745-2016, 2016. a, b
Soulsby, C., Tetzlaff, D., and Hrachowitz, M.: Tracers and transit times:
windows for viewing catchment scale storage?, Hydrol. Process., 23, 3503–3507, https://doi.org/10.1002/hyp.7501, 2009. a, b
Soulsby, C., Piegat, K., Seibert, J., and Tetzlaff, D.: Catchment-scale
estimates of flow path partitioning and water storage based on transit time
and runoff modelling, Hydrol. Process., 25, 3960–3976, https://doi.org/10.1002/hyp.8324, 2011. a
Sprenger, M., Leistert, H., Gimbel, K., and Weiler, M.: Illuminating
hydrological processes at the soil-vegetation-atmosphere interface with water
stable isotopes, Rev. Geophys., 54, 674–704, https://doi.org/10.1002/2015RG000515, 2016. a
Sprenger, M., Stumpp, C., Weiler, M., Aeschbach, W., Allen, S. T., Benettin,
P., Dubbert, M., Hartmann, A., Hrachowitz, M., Kirchner, J. W., McDonnell, J. J., Orlowski, N., Penna, D., Pfahl, S., Rinderer, M., Rodriguez, N., Schmidt, M., and Werner, C.: The demographics of water: A review of water ages in the critical zone, Rev. Geophys., 57, 800–834, https://doi.org/10.1029/2018RG000633, 2019. a
Stamoulis, K., Ioannides, K., Kassomenos, P., and Vlachogianni, A.: Tritium
Concentration in Rainwater Samples in Northwestern Greece, Fusion Sci. Technol., 48, 512–515, https://doi.org/10.13182/FST05-A978, 2005. a
Stewart, M. K. and Morgenstern, U.: Importance of tritium-based transit times
in hydrological systems, Wiley Interdisciplin. Rev.: Water, 3, 145–154,
https://doi.org/10.1002/wat2.1134, 2016. a, b
Stewart, M. K. and Thomas, J. T.: A conceptual model of flow to the Waikoropupu Springs, NW Nelson, New Zealand, based on hydrometric and tracer (18O, Cl, 3H and CFC) evidence, Hydrol. Earth Syst. Sci., 12, 1–19, https://doi.org/10.5194/hess-12-1-2008, 2008. a, b, c
Stewart, M. K., Mehlhorn, J., and Elliott, S.: Hydrometric and natural tracer
(oxygen-18, silica, tritium and sulphur hexafluoride) evidence for a dominant
groundwater contribution to Pukemanga Stream, New Zealand, Hydrol. Process., 21, 3340–3356, https://doi.org/10.1002/hyp.6557, 2007. a, b, c, d
Stewart, M. K., Morgenstern, U., Gusyev, M. A., and Małoszewski, P.:
Aggregation effects on tritium-based mean transit times and young water fractions in spatially heterogeneous catchments and groundwater systems, Hydrol. Earth Syst. Sci., 21, 4615–4627,
https://doi.org/10.5194/hess-21-4615-2017, 2017. a
Stumpp, C., Klaus, J., and Stichler, W.: Analysis of long-term stable isotopic composition in German precipitation, J. Hydrol., 517, 351–361,
https://doi.org/10.1016/j.jhydrol.2014.05.034, 2014. a
Thiesen, S., Darscheid, P., and Ehret, U.: Identifying rainfall-runoff events
in discharge time series: a data-driven method based on information theory,
Hydrol. Earth Syst. Sci., 23, 1015–1034, https://doi.org/10.5194/hess-23-1015-2019, 2019. a
Uhlenbrook, S., Frey, M., Leibundgut, C., and Maloszewski, P.: Hydrograph
separations in a mesoscale mountainous basin at event and seasonal timescales, Water Resour. Res., 38, 31-1–31-14, https://doi.org/10.1029/2001WR000938, 2002. a, b
van der Velde, Y., Heidbüchel, I., Lyon, S. W., Nyberg, L., Rodhe, A.,
Bishop, K., and Troch, P. A.: Consequences of mixing assumptions for
time-variable travel time distributions, Hydrol. Process., 29, 3460–3474, https://doi.org/10.1002/hyp.10372, 2015. a, b, c, d
van Meerveld, H. J. I., Kirchner, J. W., Vis, M. J. P., Assendelft, R. S., and Seibert, J.: Expansion and contraction of the flowing stream network alter hillslope flowpath lengths and the shape of the travel time distribution, Hydrol. Earth Syst. Sci., 23, 4825–4834, https://doi.org/10.5194/hess-23-4825-2019, 2019. a
Visser, A., Thaw, M., Deinhart, A., Bibby, R., Safeeq, M., Conklin, M., Esser, B., and Van der Velde, Y.: Cosmogenic Isotopes Unravel the Hydrochronology and Water Storage Dynamics of the Southern Sierra Critical Zone, Water Resour. Res., 55, 1429–1450, https://doi.org/10.1029/2018WR023665, 2019. a, b, c, d, e, f, g, h
von Freyberg, J., Studer, B., and Kirchner, J. W.: A lab in the field:
high-frequency analysis of water quality and stable isotopes in stream water
and precipitation, Hydrol. Earth Syst. Sci., 21, 1721–1739,
https://doi.org/10.5194/hess-21-1721-2017, 2017. a, b
Vrugt, J. A.: Markov chain Monte Carlo simulation using the DREAM software
package: Theory, concepts, and MATLAB implementation, Environ. Model. Softw., 75, 273–316, https://doi.org/10.1016/j.envsoft.2015.08.013, 2016. a
Waichler, S. R., Wemple, B. C., and Wigmosta, M. S.: Simulation of water
balance and forest treatment effects at the H. J. Andrews Experimental Forest, Hydrol. Process., 19, 3177–3199, https://doi.org/10.1002/hyp.5841, 2005. a
Wilusz, D. C., Harman, C. J., and Ball, W. P.: Sensitivity of Catchment Transit Times to Rainfall Variability Under Present and Future Climates,
Water Resour. Res., 53, 10231–10256, https://doi.org/10.1002/2017WR020894, 2017. a
Wrede, S., Fenicia, F., Martínez-Carreras, N., Juilleret, J., Hissler, C., Krein, A., Savenije, H. H. G., Uhlenbrook, S., Kavetski, D., and Pfister, L.: Towards more systematic perceptual model development: a case study using 3 Luxembourgish catchments, Hydrol. Process., 29, 2731–2750, https://doi.org/10.1002/hyp.10393, 2015. a, b, c
Zuber, A.: On the interpretation of tracer data in variable flow systems, J. Hydrol., 86, 45–57, https://doi.org/10.1016/0022-1694(86)90005-3, 1986. a
Short summary
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.
Different parts of water have often been used as tracers to determine the age of water in...