Daily time-series data of PM10 and PM2.5 on ten locations in Taiyuan City were employed to analyze spatiotemporal characteristics, as well as the synchronous variations with the anthropogenic activities. Main influence variables on different time-scales were identified based on PCA. The results indicated that the obvious spatiotemporal differences were observed on PM10 and PM2.5 changes. The relatively higher concentrations of PM2.5 and PM10 in the newly downtown zones, comparing with those in the traditional heavy energy-consumption zones. The particle matter concentrations in winter showed relatively higher values. The wavelet analysis revealed that the period structures of both PM10 and PM2.5 time series were 4~8 days (P<0.05), which indicated the weekly cycle fluctuations synchronized with human activities. The higher values of PM10 and PM2.5 concentrations occurred in midweek, but lower values on the weekend. The PCA results revealed the main influence variables of winter on seasonal scale, Wednesday on weekly scale, and Night and Morning on daily scale for PM10 and PM2.5, separately. The variations of PM10 and PM2.5 concentrations on daily scale can be explained by the changes occurred on Daytime scale because of the approximate horizontal variable showed in PCA result. The research demonstrated the variations of PM10 and PM2.5 on different time-scale in a heavy energy-consumption city, and which also provided a new perspective for effective prevention and control of atmospheric pollution, as well as the scientific basis of relative standards and specifications for government.%选取太原市城区10个监测点2014—2016年PM10和PM2.5日变化数据,分析和探讨了其时空变化特征,及其与人类经济活动的同步性规律;采用小波连续变换的功率谱方法识别颗粒物周期变化特征,采用可视化主成分分析法识别不同时间尺度下颗粒物变化的影响因素.结果表明,太原市大气颗粒污染物PM10和PM2.5质量浓度的变化存在明显的时空差异,新兴经济发展区较传统老工业区污染严重,颗粒物污染程度在冬季较为严重.小波分析结果显示,PM10和PM2.5时间序列的变化周期均以4~8 d的短周期为主(P<0.05),污染物的质量浓度变化与城市经济活动的周波动变化相一致;PM10和PM2.5质量浓度最大值出现在周波动的中间时段,最小值出现在周末.可视化PCA结果揭示,大气颗粒物PM10和PM2.5季节性波动均受冬季影响较强;周波动周期内均受周三影响最大;一天之内PM10和PM2.5质量浓度分别受夜晚和早晨影响最大,但白天颗粒物质量浓度变化是造成其日变化特征的主要因素.研究结果有利于从不同时间尺度辨析能源城市大气颗粒物污染的多变特征,有针对性地开展大气污染防控,也可为管理部门制定相关标准和规范提供科学依据.
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