Long Term Greenhouse Gas Emissions from the Hydroelectric Reservoir of Petit Saut (French Guiana) and Potential Impacts

Abstract

This paper summarizes, in a first part, results of greenhouse gas emissions from the hydroelectric reservoir of Petit Saut in French Guiana obtained during the three first years after impoundment (1994–1997). Results from three years of measurements have been extrapolated to estimate trends in methane emissions and the carbon budget of the reservoir over a 20-year period. Extrapolations were made using the global warming potential concept to calculate cumulative greenhouse gas emissions at a 100-year time horizon and to compare these emissions to potential emissions from thermal alternatives. In a second part, we analyze new data from long term continuous observations (1994–2003) of methane concentrations in the reservoir and flux data obtained during a recent campaign in May 2003. These data confirm predicted trends and show some suitable adjustments. They constitute a unique data base which is used for the development of a model to simulate both water quality and greenhouse gas emissions from tropical artificial reservoirs.