Numerical study of weathering fluxes at the catchment scale in a boreal watershed: a coupled thermo-hydro-geochemical mechanistic approach.

• Main Authors: Orgogozo, L., Godderis, Y., Pokrovsky, O., Viers, J., Labat, D., Prokushkin, A, Dupré, B
• Other Authors: Géosciences Environnement Toulouse (GET), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales Toulouse (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales Toulouse (CNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD), Laboratoire des Mécanismes et Transfert en Géologie (LMTG), Université Toulouse III - Paul Sabatier (UT3), Météo France-Centre National d'Études Spatiales Toulouse (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales Toulouse (CNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Recherche de l'Ecole Nationale Supérieure du Paysage (LAREP), Ecole Nationale Supérieure Polytechnique de Yaoundé (ENSPY), Université de Yaoundé I-Université de Yaoundé I
• Format: Conference Object
• Language: English
• Published: HAL CCSD 2011
• Subjects: [INFO.INFO-MO]Computer Science [cs]/Modeling and Simulation; [PHYS.MPHY]Physics [physics]/Mathematical Physics [math-ph]; [SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces; environment; [SDU.STU.GC]Sciences of the Universe [physics]/Earth Sciences/Geochemistry; [SDU.STU.GL]Sciences of the Universe [physics]/Earth Sciences/Glaciology; [SDU.STU.HY]Sciences of the Universe [physics]/Earth Sciences/Hydrology; permafrost
• Online Access: https://hal.archives-ouvertes.fr/hal-01882522; https://hal.archives-ouvertes.fr/hal-01882522/document; https://hal.archives-ouvertes.fr/hal-01882522/file/poster_orgogozo_permafrost_2011.pdf

International audience This work deals with the assessment of the impact of the climatic changes on weathering processes in boreal catchments which are characterized by the occurrence of a continuous permafrost. The two main goals of this study are : (i) to quantify the influence of seasonal cycles of freezing and thawing of the active layer on the fluxes of chemical elements generated by the weathering processes and (ii) to estimate the effect on the weathering fluxes of possible interannual variations of these cycles caused by climatic changes. Our approach is based on the development and the validation of a coupled thermo-hydrological mechanistic modelling at the catchment scale for current climatic conditions. This thermo-hydrological model is designed to give the entrance data (the seasonal evolutions of the average thickness and of the average water content of the active layer) for the computation of weathering fluxes with the WHITCH geochemical model (e.g. [1]). This modelling approach at the catchment scale is established on the basis of the data available in the International Research Group CAR WET SIB ([2], [3]). In further studies, the model developed here will allow to forecast the impact of various scenarios of climatic changes on the weathering fluxes.[1] Goddéris et al. (2006) Geochim. Cosmochim. Acta 70, 1128-1147. [2] Bagard et al. (in press) Geochim. Cosmochim. Acta. [3] Pokrovsky et al. (2005) Geochim. Cosmochim. Acta 69, 5659-5680.