Properties of CO2 and CH4 fluxes across water-air interface at the Three Gorges Reservoir, the mainstream of Yangtze River from Zhutuo to Wanzhou, China

The Three Gorges Reservoir is one of the most important hydraulic projects of the Yangtze River in China, so it is vital to monitor p (CO2), p(CH4) and CO2 CH4 fluxes in water-air interface in a long term. Five monitoring sites (Zhutuo, Mudong, Fulin, Zhongxian and Wanzhou) were chosen from the mainstreams of the Yangtze River in this study. CO2 and CH4 were monitored monthly for period of 1 year from May of 2016. Results indicated that in the mainstream of the Yangtze River p (CO2) and CO2 fluxes were 1,246.99-4,495.20 mu atm and (41.29 +/- 4.46) mmol m(-2) d(-1), respectively. The p(CH4) and CH4 fluxes were 21.63-588.28 mu atm and (0.168 +/- 0.028) mmol m(-2) d(-1). The p(CH4) had a positive correlation with water temperature, while negative correlation with dissolved oxygen (DO). The p (CO2) also had a significant positive correlation with water temperature, but negative correlation with conductivity, DO, pH and wind speed. Water-air CH4 and CO2 fluxes mainly impacted by p(CH4), p (CO2), water temperature, DO, conductivity and pH.