TY - JOUR
T1 - City-level air quality improvement in the Beijing-Tianjin-Hebei region from 2016/17 to 2017/18 heating seasons
T2 - Attributions and process analysis
AU - Zhang, Yibo
AU - Chen, Xue
AU - Yu, Shaocai
AU - Wang, Liqiang
AU - Li, Zhen
AU - Li, Mengying
AU - Liu, Weiping
AU - Li, Pengfei
AU - Rosenfeld, Daniel
AU - Seinfeld, John H.
N1 - Publisher Copyright:
© 2021 Elsevier Ltd
PY - 2021/4/1
Y1 - 2021/4/1
N2 - With the implementation of clean air strategies, PM2.5 pollution abatement has been observed in the “2 + 26” cities in the Beijing-Tianjin-Hebei (BTH) region (referred to as the BTH2+26) and their surrounding areas. To identify the drivers for PM2.5 concentration decreases in the BTH2+26 cites from the 2016/17 heating season (HS1617) to the 2017/18 heating season (HS1718), we investigated the contributions of meteorological conditions and emission-reduction measures by Community Multi-Scale Air Quality (CMAQ) model simulations. The source apportionments of five sector sources (i.e., agriculture, industry, power plants, traffic and residential), and regional sources (i.e., local, within-BTH: other cities within the BTH2+26 cities, outside-BTH, and boundary conditions (BCON)) to the PM2.5 decreases in the BTH2+26 cities were estimated with the Integrated Source Apportionment Method (ISAM). Mean PM2.5 concentrations in the BTH2+26 cities substantially decreased from 77.4 to 152.5 μg m−3 in HS1617 to 52.9–101.9 μg m−3 in HS1718, with the numbers of heavy haze (daily PM2.5 ≥150 μg m−3) days decreasing from 17-77 to 5–30 days. The model simulation results indicated that the PM2.5 concentration decreases in most of the BTH2+26 cities were attributed to emission reductions (0.4–55.0 μg m−3, 2.3–81.6% of total), but the favorable meteorological conditions also played important roles (1.9–25.4 μg m−3, 18.4–97.7%). Residential sources dominated the PM2.5 reductions, leading to decreases in average PM2.5 concentrations by more than 30 μg m−3 in severely polluted cities (i.e., Shijiazhuang, Baoding, Xingtai, and Beijing). Regional source analyses showed that both local and within-BTH sources were significant contributors to PM2.5 concentrations for most cities. Emission controls in local and within-BTH sources in HS1718 decreased the average PM2.5 concentrations by 0.1–47.2 μg m−3 and 0.3–22.1 μg m−3, respectively, relative to those in HS1617. Here we demonstrate that a combination of favorable meteorological conditions and anthropogenic emission reductions contributed to the improvement of air quality from HS1617 to HS1718 in the BTH2+26 cities.
AB - With the implementation of clean air strategies, PM2.5 pollution abatement has been observed in the “2 + 26” cities in the Beijing-Tianjin-Hebei (BTH) region (referred to as the BTH2+26) and their surrounding areas. To identify the drivers for PM2.5 concentration decreases in the BTH2+26 cites from the 2016/17 heating season (HS1617) to the 2017/18 heating season (HS1718), we investigated the contributions of meteorological conditions and emission-reduction measures by Community Multi-Scale Air Quality (CMAQ) model simulations. The source apportionments of five sector sources (i.e., agriculture, industry, power plants, traffic and residential), and regional sources (i.e., local, within-BTH: other cities within the BTH2+26 cities, outside-BTH, and boundary conditions (BCON)) to the PM2.5 decreases in the BTH2+26 cities were estimated with the Integrated Source Apportionment Method (ISAM). Mean PM2.5 concentrations in the BTH2+26 cities substantially decreased from 77.4 to 152.5 μg m−3 in HS1617 to 52.9–101.9 μg m−3 in HS1718, with the numbers of heavy haze (daily PM2.5 ≥150 μg m−3) days decreasing from 17-77 to 5–30 days. The model simulation results indicated that the PM2.5 concentration decreases in most of the BTH2+26 cities were attributed to emission reductions (0.4–55.0 μg m−3, 2.3–81.6% of total), but the favorable meteorological conditions also played important roles (1.9–25.4 μg m−3, 18.4–97.7%). Residential sources dominated the PM2.5 reductions, leading to decreases in average PM2.5 concentrations by more than 30 μg m−3 in severely polluted cities (i.e., Shijiazhuang, Baoding, Xingtai, and Beijing). Regional source analyses showed that both local and within-BTH sources were significant contributors to PM2.5 concentrations for most cities. Emission controls in local and within-BTH sources in HS1718 decreased the average PM2.5 concentrations by 0.1–47.2 μg m−3 and 0.3–22.1 μg m−3, respectively, relative to those in HS1617. Here we demonstrate that a combination of favorable meteorological conditions and anthropogenic emission reductions contributed to the improvement of air quality from HS1617 to HS1718 in the BTH2+26 cities.
KW - Air quality improvement
KW - BTH2+26 cities
KW - Emission reduction
KW - Meteorological contribution
KW - Source apportionment
UR - http://www.scopus.com/inward/record.url?scp=85099800527&partnerID=8YFLogxK
U2 - 10.1016/j.envpol.2021.116523
DO - 10.1016/j.envpol.2021.116523
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C2 - 33508716
AN - SCOPUS:85099800527
SN - 0269-7491
VL - 274
JO - Environmental Pollution
JF - Environmental Pollution
M1 - 116523
ER -
