2019年10~12月京津冀及周边“2+26”城市重污染减排效果评估

Assessment of Emergency Emission Reduction Effect During the Heavy Air Pollution Episodes in Beijing,Tianjin,Hebei,and Its Surrounding Area(“2+26”Cities)from October to December 2019

为评估京津冀及周边区域重污染过程期间应急减排措施的效果,基于情景模拟的方法,采用NAQPMS模式和多种观测资料,分析了2019年10~12月期间京津冀及周边区域环境空气质量、重污染过程和气象条件概况,评估了模式24、72和144 h的PM2.5预报效果,并对应急减排措施的效果和不确定性进行了讨论.结果表明,2019年10~12月京津冀及周边"2+26"城市PM2.5平均浓度64μg·m^-3,同比降低了10μg·m^-3;区域性重污染过程4次,受影响城市重污染过程期间PM2.5平均浓度156μg·m^-3."2+26"城市PM2.5气象条件评估指数(EMI)变化值范围为-15.6%~16.8%,EMI显示北京、天津和石家庄等12个城市气象条件与同期相比变差,变差程度范围为3.2%~16.8%.减排情景模拟分析显示应急减排措施有效减少了区域性重污染过程的发生,污染物峰值浓度降幅明显,未出现区域性严重污染过程.典型重污染期间,北京、石家庄、保定和唐山等城市PM2.5日均浓度削减2%~9%.区域应急减排措施促使"2+26"城市PM2.5季度均值分别降低1~3μg·m^-3左右,区域性减排效果明显.

To evaluate the effect of emergency emission reduction measures during the heavy air pollution episodes in Beijing,Tianjin,Hebei,and its surrounding areas,a scenario simulation method was used.The concentrations of PM2.5,PM10,SO2,NO2,CO,and O3-8 h,air quality index(AQI),characteristics of heavy air pollution,and climate and meteorological factors were analyzed using the observation data available from October to December 2019.The 24 h,72 h,and 144 h prediction results of NAQPMS model were analyzed.The uncertainties of the assessment and model prediction were discussed.The results showed that the average PM2.5 concentration in Beijing,Tianjin,and its surrounding 26 cities("2+26"cities)from October to December 2019 was 64μg·m^-3,indicating a decrease of 10μg·m^-3 as compared with that during the same period in 2018.There were 4 occurrences of regional heavy air pollution episodes,with the average PM2.5 concentration of 156μg·m^-3 of affected cities.The value of evaluation on meteorological condition index of PM2.5 pollution(EMI)of"2+26"cities ranged from-15.6%-16.8%.The meteorological conditions of 12 cities,including Beijing,Tianjin,and Shijiazhuang,deteriorated as compared with those during the same period in 2018,and the changes ranged from 3.2%-16.8%.However,the emergency emission reduction measures effectively reduced the occurrence of regional heavy air pollution episodes,the peak concentration of PM2.5 was decreased significantly,and no severe regional pollution episode occurred.The daily PM2.5 concentrations reduced by 2%to 9%in Beijing,Shijiazhuang,Baoding,Tangshan,and other cities during a typical heavy air pollution period.The quarterly average concentrations of PM2.5 in the"2+26"cities reduced by 1 to 3μg·m^-3.The regional emergency emission reduction measures have played an active role in protecting the health of the people and improving the quality of ambient air.