天津蓟县夏季PM_(2.5)污染特征及影响因素

Pollution Characteristics and Influence Factors of PM_(2.5) in Summer in Jixian County of Tianjin

为探究天津蓟县大气细颗粒物(PM2.5)污染特征及气象因素对它的影响,搜集了2013年蓟县PM2.5质量浓度变化资料,对PM2.5污染情况进行了详细分析;并针对夏季典型天气,对PM2.5质量浓度进行监测,结合同步气象数据,运用线性回归及相关性分析方法研究PM2.5质量浓度与气象因素关系.结果表明:蓟县PM2.5质量浓度呈现明显冬高夏低特征,夏季污染超标率达45%,其日变化呈明显双峰型;PM2.5质量浓度受温度、相对湿度、风速、风向、降雨影响显著,与气压无显著关系,能见度随PM2.5质量浓度增大呈现e指数衰减规律.研究结果可为当前的京津冀区域大气污染协同防控提供一定的科学参考.

In order to investigate fine particulate matter（PM2.5）pollution characteristics and the effects of meteoro-logical factors on PM2.5 in Jixian county of Tianjin,PM2.5 mass concentrations in 2013 were collected and PM2.5 pol-lution characteristics were analyzed in detail. Then PM2.5 mass concentration was monitored and recorded in typical weathers of summer. With synchronous meteorological data,the associations between PM2.5 mass concentration and meteorological factors were studied by using linear regression and correlation analysis methods. The results show that PM2.5 mass concentration is remarkably high in winter and relatively low in summer. The rate of exceeding allowable limit reaches 45%in summer and daily average variation of PM2.5 mass concentration shows a distinct bimodal pattern. In addition,PM2.5 mass concentration is significantly affected by temperature,relative humidity,wind speed, wind direction and rainfall,but not significantly associated with atmospheric pressure. Besides,visibility presents an exponential decay trend as PM2.5 mass concentration increases. The results possess certain scientific reference for syn-ergetic prevention and control of air pollution in the Beijing-Tianjin-Hebei region.