CO2 fluxes at the water-atmosphere interface in fluvial environments: an overview of studies in Brazilian rivers

Abstract

Recent advances in Brazilian scientific production on CO2 fluxes at the water-atmosphere interface in rivers were reviewed, including estimates of CO2 partial pressure and fluxes. A total of 17 studies were reviewed. We compiled information regarding the location studied, the methodology used by each author, and the values of CO2 partial pressure (pCO2), CO2 fluxes (FCO2), and gas exchange coefficient (k) found in each region. The results were spatialized and synthesized. The important role of fluxes in CO2 degassing and their influence on climate change, as well as the global lack of data on these environments, were the main motivations for this study. The information was scarce, and most studies are focused on the Amazon Basin. However, high-resolution mapping of CO2 fluxes, at the scale of micro basins and streams, proved to be scarce. We emphasize, therefore, the importance of further studies in the country including other hydrographic regions, and in high resolution. These studies would add to our knowledge of how natural and anthropic processes influence CO2 flux, in addition to providing better estimates in tropical river systems.
 Keywords: climate change, CO2 emission, CO2 partial pressure.