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Gaseous emissions and oxygen consumption in hydroelectric dams: A case study in French Guyana
Author(s) -
GalyLacaux Corinne,
Delmas Robert,
Jambert Corinne,
Dumestre JeanFrançois,
Labroue Louis,
Richard Sandrine,
Gosse Philippe
Publication year - 1997
Publication title -
global biogeochemical cycles
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.512
H-Index - 187
eISSN - 1944-9224
pISSN - 0886-6236
DOI - 10.1029/97gb01625
Subject(s) - environmental science , carbon dioxide , methane , hydroelectricity , hydrology (agriculture) , greenhouse gas , carbon fibers , hydrogen sulfide , environmental chemistry , oceanography , chemistry , geology , ecology , sulfur , materials science , geotechnical engineering , organic chemistry , composite number , composite material , biology
Methane, carbon dioxide, and hydrogen sulfide emissions from the hydroelectric dam of Petit Saut on the Sinnamary River in French Guyana have been measured over a 2 year period. Since the beginning of the reservoir filling (January 1994), 300 km 2 of tropical forest have been submerged. Emissions of CH 4 by diffusion and by bubbling into the atmosphere or by degassing of the water released into the river, as well as the stock of dissolved gases in the lake, and their temporal evolutions were determined. Maximum emissions of 800 t CH 4 per day were reached in February 1995, corresponding to dissolved CH 4 concentrations of 14 mg 4 L −1 in the water column. The biological oxidation of methane results in a strong oxygen consumption in lake and river waters. Total emissions of CH 4 and CO 2 from January 1994 to December 1995 were calculated from the whole data set, which also allows us to calculate the total carbon loss since reservoir filling. About 10% of the carbon stored in soil and vegetation was released in gaseous form within 2 years.