2015年中国地区大气甲烷排放估计及空间分布

CH₄是仅次于CO₂的重要温室气体，也是重要的化学活性气体.定量估算我国甲烷的排放量及分析其空间分布特征，对于控制温室气体排放，减缓温室效应具有重要意义.本文以2015年中国官方统计年鉴资料为基础，利用IPCC排放清单指南、国内外排放因子研究结果及动力学模型方法，从能源活动（煤炭开采和油气系统）、农业活动（反刍动物、稻田排放和秸秆露天燃烧）、自然源排放（自然湿地和植被排放）、废弃物处理（固体废弃物、工业污水和生活污水）和人工湿地等几个主要方面，对中国地区的CH₄排放进行定量估计.结果表明：中国地区2015年CH₄排放总量为61.59 Tg，其中以农业活动和能源活动为主要排放源，排放量分别达到20.42 Tg和20.39 Tg，占总排放量比例分别约为33.2%和33.1%.CH₄自然源考虑了植被和自然湿地排放，排放量为11.77 Tg，占比为19.1%；废弃物处理产生的CH₄排放量为8.64 Tg，占比为14.0%；人工湿地排放量为0.37 Tg，占比为0.6%.从空间分布来看，CH₄排放具有较明显的不均匀性，大值区主要集中在华北、西南及东南地区，而西北地区的排放量则相对较低，主要与各地的资源环境、人口密度和经济情况密切相关.

Estimation of atmospheric methane emissions and its spatial distribution in China during 2015

Atmospheric methane is the second most important greenhouse gas only after CO₂, and it is a chemically active gas in the atmosphere. Quantitative estimation of China''s methane emissions and analysis of its spatial distribution are of great significance for controlling greenhouse gas emissions and slowing down the greenhouse effect. Based on the 2015 China Official Statistical Yearbook data, we use the latest IPCC inventory guidelines, results from domestic and international emission factor research, as well as kinetic model methods, to quantitatively investigate the emission of methane in China. Different emission sources, such as energy activities (coal mining and oil and gas systems), agricultural activities (ruminants, paddy field emissions and field burning of crop residues), natural sources (natural wetlands and vegetation discharge), waste treatment (municipal solid waste landfill and wastewater management) and artificial wetland are included in our research. Results show that the total methane emission in China is 61.59 Tg in the year of 2015. Agricultural activities and energy activities were the main sources of emissions, with emissions reaching 20.42 Tg and 20.39 Tg, respectively, accounting for 33.2% and 33.1% of the total emissions. Vegetation and wetland emissions are considered in the natural sources, and the emissions from natural sources is 11.77 Tg, accounting for 19.1%. Waste treatment contributes 8.64 Tg to the total emission, accounting for 14.0%. The amount of emissions from artificial wetland is 0.37 Tg, accounting for 0.6%. We found that the CH₄ emissions are heterogeneously distributed over China, and the distribution is closely related to local resources and environment, population density and the economic situation. Large emissions are concentrated in North China, Southwest China and Southeast China, while the emissions over Northwest China''s are relatively low.