农业环境科学学报2012，Vol.31Issue(8)：1576-1585,10.
我国河流N2O饱和度与释放系数变化及其与河流氮水平的关系研究
Variations of River N2O Saturations and Emission Factors in Relation to Nitrogen Levels in China
摘要
Abstract
Nitrous oxide( N2O) is a potent greenhouse gas that contributes the climate changes and stratospheric ozone depletion. An increase of active nitrogen( N ) loading resulting from human activities to watersheds makes river systems a potentially important source of N20. Here, we present the results of spatial and temporal variations of river N2O saturations and emissions in relation to N levels from rivers among three watersheds with multiple land uses in China, and we also assess the emission factors based on the Intergovernmental Panel on Climate Changes(lPCC) guidelines. The results showed that nitrate and ammonium concentrations ranged from 0.023 to 5.24( average 1.29±0.822) mg·L‐1 and from 0.020 to 40.3( average 2.54±5.47)mg N·L‐1, respectively ;Correspondingly, N2O saturations and emissions ranged from 90% to 8213%( average 407%±1010% ) and from 0.250 to 1960(average 58.3±221 )μg N ·m‐2·h‐1, respectively among the rivers. Our study demonstrated all the rivers were sources of N20 to the atmosphere. There existed significant differences of ammonium concentrations, N2O saturations and emissions for rivers in these watersheds, and the highest mean values of ammonium concentrations, N2O saturations and emissions were ( 12.5±6.10)mg N·L‐1, 1760%±2620% and (363±548)μg N·m‐2·h‐1, respectively, which were observed in Nanfei River receiving urban waste waters. We found N2O saturations from study rivers (except for the Nanfei River) were positively related to nitrate concentrations, demonstrating that rivers with increased nitrate levels can results in more N2O production. On the basis of the IPCC definition of "emission factor", the measured emission factor ranged from 0.05% to 0.87%, with an average of 0.2%, very close to IPCC given value of 0.25%. However, our study suggests that the revised "actual" emission factor with an average value of 0.1 % is more appropriate instead of IPCC value.关键词
河流/氧化亚氮/饱和度/释放量/释放系数/硝态氮/氨氮Key words
river/ N2O/ saturation/ emission/ emission factor/ nitrate/ ammonium分类
资源环境引用本文复制引用
王佳宁,晏维金,陈能汪,王蓓,杨丽标..我国河流N2O饱和度与释放系数变化及其与河流氮水平的关系研究[J].农业环境科学学报,2012,31(8):1576-1585,10.基金项目
国家自然科学基金(20777073) （20777073）
中国科学院地理科学与资源研究所前沿探索项目(2012QY001) （2012QY001）
国家自然科学基金(41076042) （41076042）
