Based on the data of PM2.5, PM10, O3, NO2, SO2, and CO hourly concentrations of 121 stations in 22 cities over Sichuan and Chongqing area during 2015—2016, the temporal and spatial distribution characteristics of the air pollutant concentrations and their regional differences were analyzed and discussed.Results indicate that the annual average concentration of particulate matter in most cities of the Sichuan basin is greater than the national standard, mainly centering in Zigong and Chengdu.For O3, the high concentration areas locate in the western and southern basin and Panxi region.The high concentration area of NO2 centers in Chengdu and Chongqing, while the maxima of SO2 and CO concentrations occur in Panzhihua.The monthly concentration of O3 is high in summer and low in fall and winter, while the concentrations for the other five pollutants are high in winter and low in summer.The diurnal variations of PM2.5, PM10, NO2, and CO concentrations show the bimodal distribution, characteristics of two concentration peaks appear at night and in the morning with the maxima at night and the minima in the afternoon.The diurnal patterns of O3 and SO2 show the unimodal distribution.Besides, there exist regional and seasonal disparities in the diurnal cycles.For the pollutants with the diurnal pattern of the bimodal distribution, the concentration peak is higher in the morning than at night in the plateau regions, while the situation in the regions of the basin is the opposite.%利用2015—2016年川渝地区22个城市121个国控站PM2.5、PM10、O3、NO2、SO2和CO逐时质量浓度数据, 分析大气污染物质量浓度的时空分布特征, 并探讨其区域差异.结果表明:1) 四川盆地城市群颗粒物年均质量浓度超标率高, 质量浓度高值区以自贡和成都为中心.O3质量浓度高值区主要在盆地西部、南部以及攀西地区.NO2高值中心在成都和重庆.SO2和CO质量浓度最大值均在攀枝花.2) O3月质量浓度夏季最高、秋冬季最低, 而其他5种污染物冬高夏低.3) PM2.5、PM10、NO2和CO的质量浓度日变化为双峰型, 质量浓度高峰在夜间和上午, 日最大值在晚上, 最小值在下午.O3和SO2日变化为单峰型.日变化特征还存在区域差异和季节差异.高原地区双峰型污染物的上午高峰通常高于夜间, 盆地各区域则相反.
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