At present, more than 70% of the world's rivers are blocked by dams. Although reservoirs provide many benefits for human beings, such as hydroelectric power generation, water supply, flood control, and navigation improvement, they block river continuum and cause changes in river hydrology and material cycle. Nitrous oxide (N2O) is an important greenhouse gas. The understanding of its generation and release mechanism in cascade reservoirs is an important basis for evaluating their greenhouse gas emissions. However, there is still a lack of knowledge of the generation mechanism, release level, and control factors of N2O in the reservoirs.
Professor Baoli Wang, from the Basin Biogeochemical Cycle Research Center of our Institute, cooperated with other researchers from East China Normal University and Shanghai University, and found that the hydraulic load (average water depth/retention time) of the reservoir is a key factor to control its N2O flux in the Wujiang cascade reservoirs, southwest China. After river damming, the depth and retention time of a reservoir increase, which results in seasonal stratification of dissolved oxygen, and then drives the production and release of N2O. The coupling of hydrology and material cycles in dammed rivers ultimately leads to that the reservoir hydraulic load becomes a key factor controlling N2O flux.
The study was published in Environmental Science & Technology, the authoritative journal of environmental science, under the title of "Control of the Hydraulic Load on Nitrous Oxide Emissions from Cascade Reservoirs". Professor Baoli Wang is a co-corresponding author of the article, and Professor Siliang Li also participated in this study. The study is co-funded by the National Key Research and Development Program and the National Natural Science Foundation of China.
Xia Liang*, Tao Xing, Junxiong Li, Baoli Wang*, Fushun Wang, Chiquan He, Lijun Hou, and Siliang Li. Control of the Hydraulic Load on Nitrous Oxide Emissions from Cascade Reservoirs. Environ. Sci. Technol. 2019. https://doi.org/10.10 21/acs.est.9b03438
