Skip to Main content Skip to Navigation
Theses

Modélisation hydrogéochimique des grands bassins fluviaux: implications du réchauffement climatique

Abstract : The chemical weathering of continental surfaces represents the one of carbon sinks at the Earth's surface which regulates the climate through feedback mechanism. The weathering intensity is controled by climate but also by lithology, vegetal cover, hydrology and presence of smectites and acids in soils. In this work, a study at global scale on grid cells highlighted that a CO2 concentration increase in the atmosphere would involve a decrease of evaportanspiration due to stomatal progressive closure, and a rise of soil acidity related to enhanced biospheric productivity. These changes would promote the silicates chemical weathering and as a result, would lead to CO2 consumption increase by 3% for 100 ppmv of CO2 concentration rise in the atmosphere. Then, the study on the one of the most important catchments located in arctic environment, the Mackenzie basin (Canada), showed the high sensitivity of chemical weathering to sulfuric acid production. Indeed, the Mackenzie mean CO2 consumption has decreased by 56%, taking account the pyrite presence in the catchment. In addition, the mean CO2 consumption of this basin could rise by 53% between today climate and a climatic scenario predicted for the end of century.
Complete list of metadatas

Cited literature [240 references]  Display  Hide  Download

https://tel.archives-ouvertes.fr/tel-00649185
Contributor : Williams Exbrayat <>
Submitted on : Wednesday, December 7, 2011 - 11:51:32 AM
Last modification on : Friday, January 8, 2021 - 10:12:03 AM
Long-term archiving on: : Thursday, March 8, 2012 - 2:31:02 AM

Identifiers

  • HAL Id : tel-00649185, version 1

Collections

Citation

Emilie Beaulieu. Modélisation hydrogéochimique des grands bassins fluviaux: implications du réchauffement climatique. Géochimie. Université Paul Sabatier - Toulouse III, 2011. Français. ⟨tel-00649185⟩

Share

Metrics

Record views

769

Files downloads

1155