基于 HYSPLIT 模型的达州与成都空气质量相关性研究

Research on the Correlation Mechanism of Air Quality between Dazhou and Chengdu Based on HYSPLIT Model

选取2016—2020年四川盆地霾高发季空气质量数据,对四川盆地区域污染类型进行统计分析,再基于HYSPLIT后向轨迹模式,利用聚类分析、潜在源贡献因子、浓度权重轨迹等方法,重点研究了达州比成都先污染情况下两个城市空气质量的相关性机理。结果表明:达州比成都先污染的类型占比最高,为40.7%。达州先污染类型下,其地面风场的地面风速小于成都市,地面风速>2 m/s的发生频率4.1%明显小于成都市的18.7%,达州市东东北风(ENE)、东北风(NE)、东风(E)占比最高,分别为16.7%、16.3%、15.3%。综合风速和风向两个因子,成都地面受东北向(NNE和NE)的气流影响最大,这和达州的偏东风气流方向吻合。成都污染潜在源区主要位于其城区至东南一带,其余在达州西部、南充东部、遂宁和资阳、重庆交界处、重庆西部一角、自贡和内江西南部。达州比成都先污染这种天气类型下,达州对成都的空气质量影响不是主要原因。

Selecting the air quality data of the high haze season in the Sichuan Basin from 2016 to 2020,the regional pollution types in Sichuan Basin were statistically analyzed.Based on the HYSPLIT backward trajectory model,cluster analysis,potential source contribution factor,concentration weight trajectory and other methods were used to study the correlation mechanism of air quality in the two cities under the condition that Dazhou was polluted earlier than Chengdu.The proportion of type that Dazhou was polluted earlier than Chengdu was highest,accounting for 47%.Under the type that Dazhoun was polluted earlier than Chengdu,the surface wind speed in Dazhou was lower than that in Chengdu,and the occurrence frequency of surface wind speed>2 m/s(4.1%),which was significantly lower than that in Chengdu(18.7%).The proportion of northeast wind(ENE),northeast wind(NE)and east wind(E)in Dazhou was the highest,which was 16.7%,16.3%and 15.3%,respectively.Combining the two factors of wind speed and wind direction,the ground of Chengdu was most affected by the northeastward(NNE and NE)air flow,which was consistent with the easterly air flow direction in Dazhou.The results showed that the potential sources of pollution in Chengdu were mainly located in the area from Chengdu City to the southeast of Chengdu,and the rest were in the west of Dazhou,the east of Nanchong,Suining and Ziyang,the junction of Chongqing,the western corner of Chongqing,Zigong and the southwest of Neijiang.Under the weather type that Dazhou is polluted earlier than Chengdu,the impact of Dazhou on Chengdu's air quality is not the main reason.