西安市主要大气污染物的观测分析研究

Analysis of the Air Quality Monitoring Data in Xi'an

该文分析了西安地区的AQI指数以及PM_(2.5)、PM_(10)、CO、NO、O_3、SO_2 6种污染物浓度在2013年7月到2014年4月的每小时观测数据,利用统计方法研究了各污染物不同时间尺度(小时、日、周、月)的浓度变化特征,分析了各个污染物之间的相关系数,对各个污染物之间的相互关系和相互作用进行了探讨。结果表明,PM_(2.5)、PM_(10)、CO、NO_2、O_3、SO_2的平均浓度和标准差分别为:(92.37±75.59)μg/m^3、(166.79±106.27)μg/m^3、(2.16±2.39)mg/m^3、(51.01±20.84)μg/m^3、(36.85±34.44)μg/m^3、(36.97±30.62)μg/m^3、(39.99±31.27)μg/m^3。PM_(2.5)、PM_(10)以及CO浓度都是在中午12时以及夜间12时左右达到峰值,在下午或傍晚达到低谷;O_3则是白天浓度高,夜间浓度低,清晨达到一天中的极小值;研究还发现,O_3浓度在周末要高于工作日,CO、SO_2却是周末浓度低于工作日浓度;PM_(2.5)和PM_(10)浓度都在冬季达到峰值,在夏季达到低谷,O_3浓度则是在夏季明显高于冬季。O_3与其他所有污染物之间都呈负相关,而其他污染物之间都是正相关。

Based on the hourly observation data of the AQI index,PM_(2.5),PM_(10),CO,NO,O_3 and SO_2 from July 2013 to April2014 in Xi'an,the variation characteristics of the pollutants' concentrations in different time scales(hourly,daily,weekly and monthly),the correlation coefficient and the interaction between the pollutants were analyzed through statistical methods.The results show that the average concentrations and standard deviations of PM_(2.5),PM_(10) CO,NO_2,O_3 and SO_2 are(92.37±75.59) μg/m^3,(166.79±106.27) μg/m^3,(2.16±2.39) mg/m^3,(51.01±20.84) μg/m^3,(36.85±34.44) μg/m^3,(36.97±30.62) μg/m^3,(39.99±31.27)μg/m^3,respectively.PM_(2.5),PM_(10) and CO have the maximum concentrations at about 12 am and 12 pm,and reach the minimum values in the afternoon or the evening.The O_3 concentration is higher in the daytime than that at night.The minimum value appears in the morning.Additionally,the concentrations of O_3 in weekends are larger than that in weekdays.However,the variations of CO and SO_2 have the opposite characteristics.The maximum concentrations of PM_(2.5) and PM_(10) are in winter,while the lowest values occur in summer.The concentration of O_3 in summer is obviously higher than that in winter.In addition,O_3 is negatively correlated with the other pollutants,and the correlations between the other pollutants are positive.