中文摘要：

为研究华北典型农区大气污染特征及变化趋势,于2008年和2012-2014年的夏季在山东禹城生态站,对大气中主要污染物（NO_x、O_3、SO_2和PM_（2.5））进行了观测研究。结果表明：观测期间NO_x、O_3、SO_2和PM_（2.5）的平均浓度分别为（31.8±16.8）、（77.6±27.5）、（13.1±14.3）和（84.2±41.7）μg/m~3,O3日8 h滑动平均最大值和PM_（2.5）日均值浓度超过国家二级标准的超标率分别为35%和54%;NO_x、O_3及O_x的浓度总体呈上升趋势;SO_2浓度呈下降趋势;PM_（2.5）浓度呈现波动变化;NO、O_3和SO_2呈现白天单峰型日变化形式,NO_2和PM_（2.5）日变化呈现双峰型。禹城农业区夏季大气污染主要受其偏南城市济南、泰安和聊城方向气流影响,高浓度的O_3污染的同时伴随着高浓度PM_（2.5）污染。

英文摘要：

In order to investigate the characteristics and variation trends of the air pollutants in the typical rural area of the North China Plain,NO_x,O_3,SO_2 and PM_（2.5）were monitored during the summer of 2008 and 2012-2014.The results showed that average concentration of NO_x,O_3,SO_2 and PM_（2.5）were（31.8 ±16.8）,（77.6 ±27.5）,（13.1 ±14.3）and（84.2 ±41.7）μg/m~3.The standard exceeding ratio（NAAQS StandⅡ）of O_3 and PM_（2.5）were 35% and 54% separately during the monitoring period.The concentration of NO_x and O_3 showed a rising trend while SO_2 showed a trend of decrease;the concentration of PM_（2.5）changed of a fluctuation.The diurnal variation pattern of NO,O_3 and SO_2appeared as single peak as well as NO_2 and PM_（2.5）showed bimodal pattern.Yucheng area was mainly influenced by the air mass from the south cities like Jinan,Tai＇an and Liaocheng,high concentration O_3 pollution was together with high concentration PM_（2.5）.