肇庆市一次典型污染天气的污染物来源解析

利用污染物及气象观测数据对肇庆市2018年12月17～23日大气污染过程进行了分析,采用了CMAQ-ISAM模型以及混合受体模型对本次大气污染来源进行了解析研究.结果表明,12月19～21日肇庆地区受近地面弱气压影响而形成的较为不利的污染物扩散条件,是肇庆大气污染过程的诱导因素;在本次污染发生前的清洁时段,肇庆污染主要来自于本地及清远,其贡献率分别为19. 2%和10. 7%,而受江西、湖南、湖北以及陕西等地的远距离污染物传输作用影响约为64. 5%;在污染时段,随着地面高气压场南移,肇庆地区受珠三角主要城市和粤东城市的区域传输贡献明显,肇庆、佛山、东莞、广州和惠州贡献率依次为25. 5%、14. 8%、9. 8%、9. 5%和5. 3%,河源、梅州、汕尾、揭阳、汕头和潮州这6个广东省东部城市贡献率共计13. 7%,而受福建、江西以及长江三角洲等地的远距离污染物传输作用影响约为32. 9%,且经过海上通道传输的污染物贡献更为显著.因此,输送到海面上的气溶胶颗粒经吸湿增长后回到陆地,是本次肇庆污染天气的主要成因之一.

Source Apportionment of Air Pollutants for a Typical Pollution Event in Zhaoqing

Based on observational data for pollutants and meteorology, this study analyzed the pollution episode that occurred during Dec 17th to 23th in 2018 in Zhaoqing, Guangdong Province, China. Using the source apportionment model CMAQ-ISAM and the hybrid receptor model, the regional contributions to air pollution were examined. The results showed that low-pressure conditions had an adverse effect on the diffusion of pollutants during this pollution episode in Zhaoqing. Prior to the pollution episode, pollutants were mainly derived from Zhaoqing and Qingyuan, accounting for 19.2% and 10.7% of pollutants, respectively. As well as pollutants from Guangdong Province, long-distance transport of pollutants from Jiangxi, Hunan, Hubei, and Shaanxi accounted for approximately 64.5% of the total during the non-pollution period. During the polluted episode, major cities in Pearl River Delta and the eastern part of Guangdong Province contributed more pollutants as a surface high-pressure field moved southward. Zhaoqing, Foshan, Dongguan, Guangzhou, and Huizhou contributed 25.5%, 14.8%, 9.8%, 9.5%, and 5.3% of the pollutants, respectively. Cities in the eastern part of Guangdong Province including Heyuan, Meizhou, Shanwei, Jieyang, Shantou, and Chaozhou contributed 13.7% of the total pollutants. In addition, pollutants from Fujian, Jiangxi, and the Yangtze River Delta accounted for approximately 32.9%. Furthermore, pollutants transported under marine influences were one of the main causes of this pollution episode in Zhaoqing.