An Integrated WRF-CAMx Modeling Approach for Impact Analysis of Implementing the Emergency PM2.5 Control Measures during Red Alerts in Beijing in December 2015

Abstract

In December 2015, the Beijing-Tianjin-Hebei (BTH) region experienced several episodes of heavy air pollution. Beijing municipal government therefore issued 2 red alerts on December 7 and 19, respectively, and also implemented emergency control measures to alleviate the negative effects of pollution. It is estimated that the heavy pollutions in 2 red alert periods in Beijing were due mainly to the accumulation of air pollutants from local emission sources and the transboundary transport of pollutants from surrounding areas. The collected meteorological and PM 2.5 data indicate that the severity of air pollutions were enlarged by the poor meteorological conditions along with lower mixing layer height. In this study, the WRF-CAMx modeling system was utilized not only for analyzing the contributions of PM 2.5 from different sources, but also for quantitatively assessing the effects of implementing various emergency control measures on PM 2.5 pollution control during the red alert periods. The modeling results show that local emissions were the most dominant contributors (64.8%-83.5%) among all emission sources, while the main external contributions came from the city of Baoding (3.4%-9.3%). In addition, among 5 different emission source categories, coal and traffic were the two dominant contributors to PM 2.5 concentration in urban area of Beijing. Then four pollution control scenarios were designed particularly to investigate the effectiveness of the emergency control measures, and the results show that, generally these emergency control measures have positive effects on air pollution reduction. In particular, restrictive measures of traffic volume control and industrial activity shutdown/suspension have been found as the most effective measures in comparison to other emergency control measures. It is recommended that such effective measures should be considered to implement when next time similar heavy air pollutions occur in the city of Beijing.

Environmental Effective Assessment of Control Measures Implemented by Clean Air Action Plan (2013–2017) in Beijing, China

“…Severe air pollution has existed in Beijing since the 1990s. Taking advantage of the opportunity of hosting a "2008 Olympics Games", the government developed a comprehensive plan to control air pollution and established 16 stages of atmospheric pollution control measures [1][2][3][4]. The ambient concentration of PM 10 had decreased, and the air quality had been improved in a certain extent [5][6][7][8][9].…”

An Amended Chemical Mass Balance Model for Source Apportionment of PM2.5 in Typical Chinese Eastern Coastal Cities

“…Source profiles are generally used to create input files for CMB, CMAQ, or other air quality models . However, the large uncertainty in source information and a lack of skillful technicians at local environmental protection departments have hampered the development of localized air quality models.…”

“…Source impacts were obtained after solving Equation via tracer optimization and source selection through CMB modeling, which may be subjective to a certain degree, since CMB users can manually choose tracers and sources to find the best fit solution. A series of diagnostic techniques were applied to evaluate the reliability and goodness of fit . The reduced chi square ( χ 2 ) value was used to evaluate the goodness of fit, calculated with Equation .…”

“…A series of diagnostic techniques were applied to evaluate the reliability and goodness of fit. [6,24] The reduced chi www.advancedsciencenews.com www.clean-journal.com square (χ 2 ) value was used to evaluate the goodness of fit, calculated with Equation (2).…”

“…Source profiles are generally used to create input files for CMB, [14,41] CMAQ, [42] or other air quality models. [24,43,44] However, the large uncertainty in source information and a lack of skillful technicians at local environmental protection departments have hampered the development of localized air quality models. Additionally, the requirements regarding emission reduction and clean air demand rapid analysis and a better understanding of emission sources.…”