Skip to Main content Skip to Navigation
Habilitation à diriger des recherches

Approches couplées pour la caractérisation du fonctionnement biogéochimique en zone critique: de la géochimie isotopique à la modélisation

Abstract : The critical zone, a complex and reactive interface between rocks, soil, water and atmosphere, is currently facing global scale perturbations, that need to be better understood in order to improve modeling of current and future functionning and of all services that it provides to Humanity. A multidisciplinary approach is developed to characterize the biogeochemical functioning of the critical zone, integrating field observations at several temporal and spatial scales as well as numerical modeling as a tool for predictions but also to help management. Water stable isotopes allow tracing flowpaths and to quantify water fluxes from the locale to the watershed scale. Aquatic ecosystems metabolism is a functional indicator that also inform on the resilience to perturbations. High frequency time series of dissolved oxygen were used to quantify ecosystem metabolism in lakes (casiers Girardon, gravel pit, experimental lakes of the PLANAQUA platform) and streams (Seine, Orgeval). Inorganic carbon isotopes monitoring help distinguishing carbon sources of biotic (organic matter mineralization in soil or stream) and abiotic (carbonates precipitation or dissolution, degassing) origins, based on the example of the Orgeval watershed. Isotope fractionation, both kinetic and at equilibreium, was implemented in reactive transport HYTEC code, developed at MINES ParisTech, with an application case for carbone isotopes in soil.
Document type :
Habilitation à diriger des recherches
Complete list of metadata

https://hal-mines-paristech.archives-ouvertes.fr/tel-03363518
Contributor : Sophie Guillon Connect in order to contact the contributor
Submitted on : Monday, October 4, 2021 - 9:29:06 AM
Last modification on : Wednesday, October 6, 2021 - 3:40:34 AM

File

hdr_guillon_20201021_FINAL.pdf
Files produced by the author(s)

Identifiers

  • HAL Id : tel-03363518, version 1

Citation

Sophie Guillon. Approches couplées pour la caractérisation du fonctionnement biogéochimique en zone critique: de la géochimie isotopique à la modélisation. Géochimie. Sorbonne Université, 2021. ⟨tel-03363518⟩

Share

Metrics

Record views

39

Files downloads

9