环鄱阳湖城市群空气质量时空分布

Spatial and temporal distribution of air quality of the city group around Poyang Lake

为探索近两年环鄱阳湖地区12个城市(即环鄱阳湖城市群)空气质量时空分布,运用统计学和地理信息系统(GIS)方法对2015年1月至2016年12月共24个月的空气质量监测数据进行分析,结果表明:(1)整体上,黄山污染天数最少,宣城最多,其余10个城市均存在不同程度的污染现象;O_3、PM_(10)、PM_(2.5)超标(超过《环境空气质量标准》(GB 3095—2012)二级标准限值)天数分别占非优良天数的50.29%、32.37%和93.99%。(2)空气质量指数(AQI)呈环湖核心区高,环湖上围区和环湖下围区低的分布格局,且冬季AQI明显高于春夏秋三季。(3)环鄱阳湖城市群首要污染物在夏季主要为O_3,其余季节主要为PM_(2.5)。(4)环鄱阳湖城市群AQI与PM_(2.5)相关性最显著,且PM_(2.5)与O_3、NO_2、SO_2均呈正相关,体现了前体物的二次转化对PM_(2.5)的显著影响。

To explore the spatial and temporal distribution characteristic of the air quality of12cities around Poyang Lake(city group around Poyang Lake),statistical method and geographic information system(GIS)method were used to analyze the air quality data measured in the last24months from January of2015to December of2016.The result showed Huangshan had fewest polluted days and Xuancheng had the most polluted days.The other10cities had polluted air at different levels.The days in which pollutants O3,PM10,PM2.5over the secondary standard of“Ambient air quality standard”(GB3095-2012)accounted for50.29%,32.37%and93.99%of the non-excellent days,respectively.At the level of temporal and spatial variation,the air quality index(AQI)showed a layout of being high in key area around the lake and low in inner and outside circle area around the lake.Obviously the AQI of winter was higher than that of spring,summer and autumn.From the main pollutant point of view,the primary pollutant was different from different seasons,meaning O3in summer while PM2.5in the other seasons.In terms of correlational analysis,AQI was much more related to PM2.5and the concentration of PM2.5had a positive correlation to the concentrations of O3,NO2,SO2,which proved the secondary formation of precursors had obvious effect on PM2.5concentration.