CIFOR-ICRAF s’attaque aux défis et aux opportunités locales tout en apportant des solutions aux problèmes mondiaux concernant les forêts, les paysages, les populations et la planète.

Nous fournissons des preuves et des solutions concrètes pour transformer l’utilisation des terres et la production alimentaire : conserver et restaurer les écosystèmes, répondre aux crises mondiales du climat, de la malnutrition, de la biodiversité et de la désertification. En bref, nous améliorons la vie des populations.

CIFOR-ICRAF publie chaque année plus de 750 publications sur l’agroforesterie, les forêts et le changement climatique, la restauration des paysages, les droits, la politique forestière et bien d’autres sujets encore, et ce dans plusieurs langues. .

CIFOR-ICRAF s’attaque aux défis et aux opportunités locales tout en apportant des solutions aux problèmes mondiaux concernant les forêts, les paysages, les populations et la planète.

Nous fournissons des preuves et des solutions concrètes pour transformer l’utilisation des terres et la production alimentaire : conserver et restaurer les écosystèmes, répondre aux crises mondiales du climat, de la malnutrition, de la biodiversité et de la désertification. En bref, nous améliorons la vie des populations.

CIFOR–ICRAF publishes over 750 publications every year on agroforestry, forests and climate change, landscape restoration, rights, forest policy and much more – in multiple languages.

CIFOR–ICRAF addresses local challenges and opportunities while providing solutions to global problems for forests, landscapes, people and the planet.

We deliver actionable evidence and solutions to transform how land is used and how food is produced: conserving and restoring ecosystems, responding to the global climate, malnutrition, biodiversity and desertification crises. In short, improving people’s lives.

Evidence of a water δ18O negative shift driven by intensive deep CO2 upflow at Shiwaga gas field (Rungwe, Tanzania)

Exporter la citation

Located on the flank of Ngozi volcanoes (Tanzania), the Shiwaga gas field is a spot of intense CO2(g) emanations. Physico-chemical measurements on different types of waters (rivers, puddles, and springs) as water and gas sampling were discontinuously performed over 10 years for equilibrated partial CO2 pressure calculations and stable isotopic analyses. The most striking result shows that meteoric H2O and deep originated CO2(g) exchanges are responsible for a negative 18O-shift of the studied waters in relation with waters electrical conductivity, pH, and pCO2eq changes. In spring waters, a maximum shift of − 11.2‰ in δ18O was observed and pCO2eq values up to 1196 mbar were computed. Although this trend has already been reported around the world, such extended shift is rarely measured and requires an important amount of CO2(g), with a CO2(g)/H2O ratio up more than 0.5 mol/mol. This approach is useful to better understand the hydro-geochemical processes involved in such environments. Moreover, this study evidences that an inventory as a monitoring of these gas fields are needed for the management of natural hazards and local resources.

DOI:
https://doi.org/10.1007/s12665-018-7665-2
Dimensions Nombre de citations:

Publications connexes