Abstract:

Based on the ambient air quality monitoring data and meteorological observations in 14 cities in Liaoning province from November 2015 to October 2016,the spatiotemporal characteristics of particulate matter and the influence by meteorological factors were systematically analyzed and then a clustering partition was made.The results show that PM_2.5 concentration in cities of Liaoning province has obviously seasonal variation,with the highest value in winter,followed by spring,summer,and fall.The spatial distribution of PM_2.5 concentration in Liaoning province is characterized by the highest in the central plain area,lower in hills at two side regions and the lowest in the east coastal region.According to the scatter plots of PM_2.5 concentration against meteorological parameters as well as the Spearman correlation coefficient,the cities in Liaoning province can be divided into four types,i.e.,Liaodong Peninsula type (Type I,including Dandong,Dalian,Panjin,and Yingkou),western Liaoning mountain type (Type II,including Huludao,Jinzhou,Chaoyang,and Fuxin),eastern Liaoning mountain type (Type III,Benxi and Fushun) and middle Liaoning plain type (Type IV,Tieling,Shenyang,Liaoyang and Anshan).PM_2.5 concentration increases in cities from Type I to Type IV,which is most obvious in winter.Positive correlations between PM_2.5 concentration and meteorological parameters such as air temperature,water vapor pressure and relative humidity at all cities are observed only in winter,but also observed in spring at cities of Type I and II,and in spring and summer for Type IV.PM_2.5 concentration has a negative correlation with wind speed in all cities in winter and no obvious correlation with air pressure.

Key words: PM_2.5 concentration, Spatial clustering, Meteorological parameter, Correlation