2008-2020年泛珠三角区域大气氨排放清单及分布特征

Ammonia Emissions Inventory and Distribution Characteristics in the Pan-Pearl River Delta Region from 2008 to 2020

精确的区域氨排放清单编制对于制定有效的空气污染控制措施至关重要.以福建省、江西省、湖南省、广东省、广西壮族自治区、海南省、四川省、贵州省、云南省等9省份为研究区域,基于10种不同氨排放源活动水平数据,采用排放因子法建立了泛珠三角区域2008−2020年的氨排放清单,并利用ArcGIS软件对2020年研究区的氨排放量进行1 km×1 km空间网格分配.结果表明:①2008−2020年泛珠三角区域氨排放量为2685.40×10^(3)~2839.35×10^(3) t,总体较为稳定,年变化率在−1.42%~1.88%之间,农业源占氨排放总量的92.23%~93.79%,非农业源贡献率为6.21%~7.77%.②2020年,四川省氨排放量最大,为689.07×10^(3) t,占研究区氨排放总量的24.53%;其次为云南省和湖南省,贡献率分别为14.70%和13.90%.蛋鸡、肉牛和生猪是畜禽养殖氨排放主要贡献源,其氨排放量分别为661.75×10^(3)、339.88×10^(3)和310.97×10^(3) t.尿素占氮肥施用氨排放量的97.17%.③2020年,泛珠三角区域氨排放呈显著的空间分布差异,高值区主要集中在四川省中部地区,排放强度高达481.03 t/km^(2);低值区主要位于四川省西部和云南省西北部区域.④在95%置信区间上,2020年研究区氨排放量的不确定度范围为−18.08%~20.97%,其中畜禽养殖和燃料燃烧的不确定度较低,分别为−7.43%~8.15%和−9.50%~10.32%.研究显示,泛珠三角区域历年氨排放趋势总体变化较小,以畜禽养殖排放源为主,加强畜牧业氨减排技术的积极推广和普遍实施将是显著削减氨排放的实现途径.

Accurate regional ammonia emissions inventories are critical to developing effective air pollution control measures.Taking the Pan-Pearl River Delta(PPRD)region consisting of nine provinces:Fujian Province,Jiangxi Province,Hunan Province,Guangdong Province,Guangxi Zhuang Autonomous Region,Hainan Province,Sichuan Province,Guizhou Province,and Yunnan Province as the study area,based on the emission activities of 10 different ammonia emission sources,the ammonia emission inventory of PPRD from 2008 to 2020 was constructed by using the emission factor method.Meanwhile,the ammonia emissions in 2020 were presented with 1 km×1 km spatial grid distribution through ArcGIS software.The results show:(1)During the study period of 2008-2020,ammonia emissions in PPRD Region generally showed a stable trend,ranging from 2685.40×10^(3) to 2839.35×10^(3) t,with an annual variation rate of−1.42%to 1.88%;agricultural sources accounted for 92.23%to 93.79%of the total ammonia emissions,while the non-agricultural sources accounted for 6.21%to 7.77%.(2)In 2020,Sichuan Province had the largest ammonia emissions,689.07×10^(3) t,accounting for 24.53%of the total ammonia emissions in the study area,followed by Yunnan Province and Hunan Province with emissions of 14.70%and 13.90%respectively.Laying hens,beef cattle and pigs were the main contributors to ammonia emissions from livestock and poultry farming,with ammonia emissions of 661.75×10^(3),339.88×10^(3) and 310.97×10^(3) t respectively;urea accounted for 97.17%of ammonia nitrogen emissions from nitrogen fertilizer application.(3)In 2020,the spatial distribution of ammonia emissions in PPRD Region was significantly different,the high-intensity areas mainly concentrated in central of Sichuan Province,with emission intensity reaching up to 481.03 t/km^(2);the lowintensity areas were mainly distributed in the west of Sichuan Province and the northwest of Yunnan Province.(4)At the 95%confidence interval,the uncertainty range in 2020 was from−18.08%to 20.97%,of which the uncertainty in livestock and poultry breeding and fuel combustion was lower,ranging from−7.43%to 8.15%and−9.50%to 10.32%,respectively.Our study shows that the overall trend of ammonia emissions in PPRD Region changed little over the years,with livestock and poultry farming being the main emission source.Strengthening the general implementation of ammonia emission reduction technologies in the livestock sector will be a possible way to significantly reduce ammonia emissions.