Methane emissions and hydrological structure of zeya reservoir (russia) in warm period

Estimates of methane emissions in the warm season from the Zeya reservoir, one of the biggest hydropower facilities that affects Russia’s carbon balance, were obtained for the first time based on the field measurements of methane concentrations in water and methane fluxes from the water surface. During expeditionary investigations conducted in September 2021 and July 2022, field data were collected. It was feasible to create the aquatory zoning and learn more about the water body’s thermal, oxygen, and chemical structure based on hydrological and chemical investigations. In conjunction with zoning, a digital elevation model of the Zeya reservoir’s bed was created, allowing calculating the reservoir’s total methane emission. It has been determined that marshy tributaries and shallow aquatories, where organic matter flows from the banks, are the primary sources of organic matter and methane. During the summer, when shallow waters are heated, there is a significantly larger overall methane flux from the reservoir’s surface. Methane emission coefficients from the Zeya Reservoir (8.6–17.2 kg CH4/ha) are consistent with those from surface-based boreal reservoirs that are provided in the supplements to the 2019 IPCC Guidelines.