北京地区甲烷排放的变化趋势和分布特征

依据国际上编制国家甲烷清单的方法，建立了北京城市尺度的甲烷排放清单，分析了北京地区甲烷排放的分布规律，并按10km×10km网格给出了北京地区甲烷排放强度的分布状况。1999年北京地区甲烷排放总量为296.29Gg，大约占全国排放总量的0.9%。其中，最主要的甲烷排放源为城市垃圾和化石燃料。城市垃圾源强为161.60Gg，占北京地区甲烷排放总量的54.6%；化石燃料源强为96.08Gg，占排放总量的32.4%。这充分反映了北京作为一特大城市甲烷排放受人为源干预强的特征。

Trends and Spatial Distributions of Methane Emissions in Beijing

Based on the methodology guidelines of IPCC, a city-scale methane emission inventory for Beijing in 1999 was established. The statistical data were derived from newly intensive survey and updated emission factors were referenced. Results showed that the total methane emissions were 296.29 Gg. The main sources were municipal solid waste and fossil fuel, which produced 161.60 Gg and 96.08 Gg of methane emissions, accounting for 54.6% and 32.4% of total emissions respectively. The spatial distributions of methane emission source strengths were also obtained.