Open AccessMethane emissions from newly created marshes in the drawdown area of the Three Gorges Reservoir
Author(s) -
Chen Huai,
Wu Yuyuan,
Yuan Xingzhong,
Gao Yongheng,
Wu Ning,
Zhu Dan
Publication year - 2009
Publication title -
journal of geophysical research: atmospheres
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.67
H-Index - 298
eISSN - 2156-2202
pISSN - 0148-0227
DOI - 10.1029/2009jd012410
Subject(s) - three gorges , drawdown (hydrology) , environmental science , marsh , hydrology (agriculture) , methane , scirpus , seasonality , flooding (psychology) , wetland , vegetation (pathology) , water level , atmospheric sciences , ecology , geology , groundwater , geography , medicine , psychology , geotechnical engineering , cartography , pathology , aquifer , psychotherapist , biology
The study aimed to understand the methane (CH 4 ) emission and its controlling factors in the Three Gorges Reservoir Region and to explore its implication for large dams. We measured CH 4 emissions from four vegetation stands in newly created marshes in the drawdown area of the Three Gorges Reservoir, China, in the summer of 2008. The results showed highly spatial variations of methane emissions among the four stands, with the smallest emission (0.25 ± 0.65 mg CH 4 m −2 h −1 ) in the Juncus amuricus stand, and the greatest (14.9 ± 10.9 mg CH 4 m −2 h −1 ) in the Scirpus triqueter stand. We found that the spatial variations of CH 4 emissions are caused by difference in standing water depth and dissolved organic carbon (DOC). Results also showed a special seasonal variation of CH 4 emissions in this area, i.e., maximal emissions in early July followed by a low and steady value before the winter flooding. The seasonality of CH 4 emissions was found closely related to temperature and standing water depth. Because of the large area of the drawdown zones for global dam reservoirs and a large CH 4 emission rate, such newly created marshes should not be neglected when estimating CH 4 emissions from reservoirs.