The Assessment of Relaxed Eddy Accumulation and Flux-Variance Methods for Carbon Flux Measurement at Rice Paddy

• Main Authors: Shih-Ting Tseng, 曾世廷
• Other Authors: 莊秉潔
• Format: Others
• Language: zh-TW
• Published: 2010
• Online Access: http://ndltd.ncl.edu.tw/handle/23709656839252183106

碩士 === 國立中興大學 === 環境工程學系所 === 98 === The air temperature has been increasing rapidly over the last century due to greenhouse effect, thus people pay more attention to CO2, CH4 and N2O, so called greenhouse gases. Rice paddies constitute a major source of methane because the irrigated rice fields produce an anaerobic condition. We conduct the carbon flux measurement with Relaxed Eddy Accumulation ( REA ) method in rice paddies at Wu-Fong Agricultural Research Institute and the result shows the methane emission ranged from 0.2 ~ 2 μg m-2 s -1 and the average value is 0.36 μg m-2 s -1 in flowering stage. In addition, this study also use flux-variance method for predicting sensible heat, latent heat, and CO2 flux with eddy-covariance measured data. The R2 between two methods are 0.77, 0.76 and 0.73, the slope are 0.77, 0.68 and 0.65, respectively. The flux-variance predicted CH4 fluxes range from 0.1 ~ 12 μg m-2 s-1 and average value is 0.79 μg m-2 s-1 in the whole growth period. It also suggests the maximum methane flux are in 30 ~ 40 days after transplantation.