Review of methods for measuring greenhouse gas flux from the air-water interface of reservoirs

Carbon dioxide (CO₂)and methane (CH₄)produced during decomposition of organic matter (OM)in reservoirs are emitted from the air-water interface either by diffusion or ebullition.The static-chamber,gradient descent,invert funnel,TDLAS (Tunable Diode Laser Absorption Spectroscopy)and eddy covariance are commonly used methods for measuring CO₂ and CH₄ fluxes from the air-water interface of reservoirs in abroad.In this study,we review the principle and application of above mentioned methods,their pros and cons,as well as applicability limitations.Factors affecting the emission of greenhouse gases from reservoirs are analyzed from the perspective of water, terrestrial and climatic environment.Prospects of the application of remote sensing technologies for monitoring green-house gas emissions from reservoirs are presented.Using remote sensing technologies and surface measuring methods can be complementary to each other in both time and space.Our study provides a valuable reference for monitoring greenhouse gas emissions from reservoirs in China.