Abstract:Models-3 Community Multi-scale Air Quality (CMAQ) modeling system with a high resolution inventory data over Beijing-Tianjin-Hebei region was implemented to investigate the different effects of ‘reducing a moderate amount of emission-sources ahead’ against ‘reducing a large amount of emission-sources on the peak day’ in the region, one of which is to cut emission-sources at a ratio of 50% on the peak day (Feb 13th, 2012) as described in reference [19]. Another 3 emission-sources reduction strategies: (1) cutting 75% emission-sources on the peak day; (2) cutting 25% 1day before the peak day (3) cutting 25% 2days before, were newly designed. The simulation results under these cutting strategies showed that when starting emission-sources reduction ratios of 50%, 75% on the peak day, the PM2.5 concentration decreasing ratios distribution over Beijing were uneven, with high decreasing ratios at the high PM2.5 concentration zone, resulting in more evenly distributed PM2.5 concentrations. When reducing 25% emission-sources 1~2days ahead of the peak day, Beijing encountered an overall PM2.5 concentration decrease. Both urban and rural Beijing showed a higher PM2.5 concentration decreasing ratio when reducing 25% emission-sources 1day ahead than reducing 50% emission-sources on the peak day. When the emission-sources reduction ratio on the peak day was increased to 75%, the PM2.5 decreasing ratio was higher than reducing 25% emission-sources 2days ahead over urban Beijing, which was not seen over the rural. When the PM2.5 concentration decreasing ratios of cutting 50%, 75% emission-source on the peak day were subtracted from cutting 25% emission-source 1day and 2days ahead of the peak day respectively, the difference of PM2.5 concentration decreasing ratios over Beijing were mainly positive. Over whole Beijing, reducing 25% emission-source 1day ahead would decrease more PM2.5 (4.7μg/m3, or 6%) than reducing 50% at the peak day; while reducing 25% emission-source 2days ahead would decrease more PM2.5 (2.9μg/m3or 4%) than reducing 75% at the peak day. In summary, it’s more effective for Beijing to reach the air quality standard by reducing a moderate amount of emission-sources ahead than reducing a large amount of emission-sources on the peak day.
翟世贤, 安兴琴, 孙兆彬, 刘俊. 污染源减排时刻和减排比例对北京市PM2.5浓度的影响[J]. 中国环境科学, 2015, 35(7): 1921-1930.
DI Shi-Xian, AN Xing-Qin, SUN Zhao-Bin, LIU Jun. Effects of emission-sources reduction time and ratios on PM2.5 concentration over Beijing Municipality. CHINA ENVIRONMENTAL SCIENCECE, 2015, 35(7): 1921-1930.