黔江区秋冬季大气颗粒物与相关气象条件的关系及其输送路径研究

The transportation path and the relationships with meteorological parameters of particulate matter pollution in Qianjiang of Chongqing

利用2016年9月至2017年2月黔江区PM_(2.5)和PM_(10)质量浓度及相关气象数据,研究了黔江区大气颗粒物与相关气象条件的关系及颗粒物气团输送轨迹。结果表明,黔江区PM_(2.5)、PM_(10)在同一季节内高度线性相关,二者质量浓度日小时值变化存在季节性差异,呈"双峰双谷"型; PM_(2.5)与温度、风速和降雨量均呈显著负相关,当气温低于15℃,风速﹤0. 5 m/s时,严重影响PM_(2.5)扩散,但降雨量增大,可迅速清除大气中的PM_(2.5);对2016年12月黔江区会议中心和旅游学院的后向轨迹聚类分析发现,黔江区两大气自动监测站点颗粒污染物气团主要来自于城市间输送(重庆主城区及湘西土家族苗族自治州),少部分来自长距离输送(西部的青藏高原地区);本研究建立的PM_(2.5)质量浓度预测模型能较好的预测黔江区PM_(2.5)质量浓度的变化趋势,这对于预测大气颗粒物污染事件的发生具有重要的实用价值。

The present study collected the data of the concentration of particulate matter 2.5 （PM 2.5 ） and 10 （PM 10 ） in atmosphere and the meteorological parameters, during September 2016 to February 2017 in Qianjiang of Chongqing, to show the temporal characteristics and the transportation path of the particulate matter （PM）, as well as the relationships between the PM concentration and the meteorological parameters. The results showed that the concentrations of PM 2.5 and PM 10 had a significant linear relationship with the same seasons, but there were differences of PM concentration in hour changing between different seasons. The PM 2.5 had significant negative relationships with temperature, wind speed, and precipitation, respectively. It would seriously affect the diffusion of PM 2.5 when the temperature was lower than 15 ℃ and wind speed was lower than 0.5 m/s, but the PM 2.5 will be rapidly removed when the precipitation was heavier. The cluster analysis showed that the PM pollutions were mainly from cities, including both downtown areas of Chongqing city and Tujia-Miao autonomous prefecture of Xiangxi in Hunan province, while a small part from the long distance transportation of the Qinghai-Tibet plateau in the northwest of China. The PM 2.5 concentration prediction model in this study could play an important role in predicting the occurrence of PM pollution in Qianjiang.