基于WRF-CMAQ评估秸秆禁烧对区域空气质量的影响

基于本地化的秸秆露天焚烧主要大气污染物排放清单，采用空气质量模式WRF-CMAQ，定量评估秸秆禁烧管控对东北地区空气质量的影响.结果显示，2013~2020年东北地区秸秆露天焚烧污染物排放总量整体呈现先增加再降低的趋势，每年的秸秆焚烧集中期为春耕前（3月和4月）和秋收后（10月和11月）.2017年秸秆焚烧集中期内，秸秆露天焚烧对东北三省的CO和PM_2.5浓度的贡献率分别为24.01%和39.98%，农作秸秆露天焚烧是造成东北地区空气质量下降的重要因素；相同气象条件下，2019年秸秆焚烧集中期，秸秆焚烧对东北三省大气中CO和PM_2.5浓度的贡献率较2017年同期分别下降了9.58%和13.95%，表明2019年的秸秆禁烧政策有效改善了东北地区的空气质量.同时，若东北三省均实施吉林省2019年的秸秆禁烧管控政策，则东北地区的空气质量将会进一步改善.本研究结果可为区域大气污染联防联控政策的制定提供科技支撑.

Evaluation of the impacts of straw burning ban on air quality based on WRF-CMAQ

The influence of straw burning ban policy on air quality in Northeast China was quantitatively evaluated by conducting the air quality simulation using WRF-CMAQ mode in different residue burning scenarios based on localized straw burning emission inventory. From 2013 to 2020, the total emissions of open straw burning in Northeast China showed a variation pattern of increasing at first and then decreasing. There are two crop residue burning and emission peaks in a year:before spring plowing (March and April) and after autumn harvesting (October and November). Among the three provinces, Jilin Province achieved the best results in controlling emissions from straw burning in 2019. The atmospheric CO and PM_2.5 from straw burning contribute 24.01% and 39.98% to the total concentration in Northeast China during the straw burning peaks in 2017, imposing detrimental effect on local air quality and human health. With the implement of the strict straw burning ban policy, the contribution rate of crop straw burning to atmospheric CO and PM_2.5 in the three northeastern provinces in 2019 decreased by 9.58% and 13.95% respectively compared with the same period in 2017, indicating that the straw burning ban policy in 2019 has effectively improved the air quality in Northeast China. If all three provinces in Northeast China implemented same straw burning ban policy as that in the Jilin Province in 2019, the regional air quality would be remarkably improved in the future. The results in this study can provide the technological supports for formulating the policies of regional air pollution prevention and control.