Greenhouse gas flux at reservoirs of Jiangxi Province and its influencing factors
Five reservoirs located in the Jiangxi Province(Zhelin, Baiyunshan,Doushui, Hongmen and Xiannuhu Reservoirs) were sampled in order to estimate the concentrations of greenhouse gas(GHG) in the surface of these reservoirs. The calculation for dif fusive fluxes of nitrous oxide(N2O) methane(CH4) and carbon dioxide(CO2) at the water air interface indicated that the surface of the reservoirs was a source of N2O and CH4 during the sampling period( from 0.29 to 1.05, 3.65 to 39.42 mg (m2*h) respec tively) Zhelin Reservoir( 51.56 mg (m2*h) and Xiannuhu Reservoir( 589.50 mg (m2*h) surfaces constituted sinks for CO2 In contrast, the surface of all the other reservoirs were sources of CO2(from 342.53 to 1383.21 mg (m2*h) A significant correlation was observed between the magnitude of N2 O diffusive fluxes and the TN. Water temperature, transparency and TP should affect the CH4 fluxes. There was no relationship between the CO2 emission and other environmental factors. Taking into ac count the global warming potential of N2O and CH4, the total fluxs of CO2 equivalents (TFeq CO 2 was estimated that ranged from 237.83 2267.83 mg CO2 e (m2*h).The contribution of N2O, CH4 and CO2 to TFeq CO 2 range from 13.94% to 83.26% 20.54% to 175.21% and from 140.43% to 60.99% respectively.The contribution of N2O to TFeq CO 2 were similar to that of CH4 in all res ervoirs. For Zhelin and Xiannuhu Reservoirs, the contribution of CO2 to TFeq CO 2 was negative, but it was the most significant in the other reservoirs. The TFeq CO 2 from each reservoir were equivalent to the 10.52 377.10 t C a of the carbon emissiom that were much lower than the annual CO2 emissions from themal power plants burning coal( from 0.05% to 1.12%