| Title: |
Water Oxygen Isotope Thermometer in Headwaters: Indicating Groundwater Recharge and Peatland Water Dependence on Air Temperature |
| Authors: |
Binet, Stéphane; Rosset, Thomas; Gascoin, Simon; Le Roux, Gaël; Deschamps‐berger, César; Durántez Jiménez, Pilar; Payre‐suc, Virginie; Granouillac, Franck; Moussa, Issam; Gandois, Laure |
| Contributors: |
Institut des Sciences de la Terre d'Orléans - UMR7327 (ISTO); Bureau de Recherches Géologiques et Minières (BRGM)-Institut national des sciences de l'Univers (INSU - CNRS)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS); Biogéosystèmes Continentaux - UMR7327; Bureau de Recherches Géologiques et Minières (BRGM)-Institut national des sciences de l'Univers (INSU - CNRS)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Bureau de Recherches Géologiques et Minières (BRGM)-Institut national des sciences de l'Univers (INSU - CNRS)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS); Centre de Recherche sur la Biodiversité et l'Environnement (CRBE); Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP); Communauté d'universités et établissements de Toulouse (Comue de Toulouse)-Communauté d'universités et établissements de Toulouse (Comue de Toulouse)-Université de Toulouse (EPE UT); Communauté d'universités et établissements de Toulouse (Comue de Toulouse); Centre d'études spatiales de la biosphère (CESBIO); Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales Toulouse (CNES)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université de Toulouse (EPE UT); Communauté d'universités et établissements de Toulouse (Comue de Toulouse)-Communauté d'universités et établissements de Toulouse (Comue de Toulouse); Instituto Pirenaico de Ecologìa = Pyrenean Institute of Ecology Zaragoza (IPE - CSIC); Consejo Superior de Investigaciones Cientificas España = Spanish National Research Council Spain (CSIC); Centre d'Etudes de la Neige (CEN); Centre national de recherches météorologiques (CNRM); Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Communauté d'universités et établissements de Toulouse (Comue de Toulouse)-Météo-France-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Communauté d'universités et établissements de Toulouse (Comue de Toulouse)-Météo-France-Observatoire des Sciences de l'Univers de Grenoble (Fédération OSUG)-Université Grenoble Alpes (UGA); Géographie de l'environnement (GEODE); Université Toulouse - Jean Jaurès (UT2J); Communauté d'universités et établissements de Toulouse (Comue de Toulouse)-Communauté d'universités et établissements de Toulouse (Comue de Toulouse)-Centre National de la Recherche Scientifique (CNRS); French Peatland Observatory SNO-TOURBIERES’ ‘Service National dObservation Tourbières’; French Water Isotopes in Precipitation Observatory SNO Renoir; CNRS-INSU; ANR-11-LABX-0010,DRIIHM / IRDHEI,Dispositif de recherche interdisciplinaire sur les Interactions Hommes-Milieux(2011); ANR-10-LABX-0100,VOLTAIRE,Geofluids and Volatil elements – Earth, Atmosphere, Interfaces – Resources and Environment(2010) |
| Source: |
ISSN: 0885-6087. |
| Publisher Information: |
CCSD; Wiley |
| Publication Year: |
2026 |
| Collection: |
Université Toulouse III - Paul Sabatier: HAL-UPS |
| Subject Terms: |
warming; stream water; stable isotopes; snowmelt; hydrogeology; [SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces; environment |
| Description: |
International audience ; Stable isotopes in precipitation, which fractionate with air temperature, serve as an isotope thermometer and offer valuable insights into hydrological processes. This study explores the application of this concept in a small mountainous watershed in the Pyrenees (France), where isotopic data from precipitation and streamflow were monitored over 8 years. In precipitation, a clear positive correlation between stable isotopic values in precipitation waters and air temperature was observed. In stream water, isotopic variability is primarily driven by the seasonal mixes of warm summer and cold winter waters (which transfers can be delayed by the ground), with a lesser influence from snowmelt fractionation. The annual averages isotopic composition of stream water reflect the air temperature at the time of precipitation, showing a bias toward winter conditions-periods of high streamflow-resulting in lower isotope-inferred temperatures compared to annual averages air temperature. These isotope-inferred temperatures follow linear relationships with key hydrological variables, including groundwater recharge and peatland water table depth. Notably, a 1°C increase in air temperature at the time of precipitation, corresponds to a 40% reduction in groundwater recharge efficiency and a 3 cm drop in peatland water table depth. The method identified to correct this bias provides a framework for understanding the impacts of climate variability on water resources, useful for paleohydrology and hydrogeology, particularly in mountainous regions where evapotranspiration and fractionation are limited. The isotope-inferred temperature records initial hydrological conditions and clarifies the link between upstream weather conditions and downstream hydrolo(geo) gical compartments along the atmosphere-surface-groundwater continuum of the critical zone for a better understanding of the water cycle. |
| Document Type: |
article in journal/newspaper |
| Language: |
English |
| DOI: |
10.1002/hyp.70465 |
| Availability: |
https://hal.science/hal-05567424; https://hal.science/hal-05567424v1/document; https://hal.science/hal-05567424v1/file/Hydrological%20Processes%20-%202026%20-%20Binet%20-%20Water%20Oxygen%20Isotope%20Thermometer%20in%20Headwaters%20Indicating%20Groundwater%20Recharge%20and.pdf; https://doi.org/10.1002/hyp.70465 |
| Rights: |
https://creativecommons.org/licenses/by-nc/4.0/ ; info:eu-repo/semantics/OpenAccess |
| Accession Number: |
edsbas.D623C22B |
| Database: |
BASE |