库尔勒市大气颗粒物浓度特征及来源

Concentrations characteristics and sources of particulate matter in Korla,Xinjiang,China

在塔里木盆地东北部库尔勒市大气颗粒物逐时数据(2015年1月至2020年12月)污染特征分析的基础上,利用HYSPLIT模型、聚类分析、潜在源贡献因子分析(PSCF)、浓度权重轨迹分析(CWT)分析不同季节库尔勒市颗粒物传输路径与潜在源区,揭示研究期间库尔勒市不同季节大气颗粒物的潜在源分布及其贡献水平。结果表明:2015—2020年库尔勒市PM_(2.5)、PM_(10)年均值分别为47.7±20.0、162.2±102.4μg·m^(-3),超过国家年均值二级浓度限值132%、36.3%,PM_(10)为主要污染物;颗粒物季节变化呈现冬春高、夏秋低的变化特征;PM_(2.5)/PM_(10)值春季最低(0.29),冬季最高(0.47),PM_(2.5)/PM_(10)值整体呈下降趋势;气流输送路径主要来自西风短气流,其次为吐鲁番盆地的东灌气流;塔里木盆地全年四季都是库尔勒市颗粒物的主要贡献源区,颗粒物浓度贡献水平春冬季较高,夏秋季较低。

Based on the analysis of the pollution characteristics in the hourly data(January 2015-December 2020)of atmospheric particulate matter in Korla of the northeastern Tarim Basin,the backward trajectory model of HYSPLIT,cluster analysis,potential source contribution factor(PSCF),and concentration weight trajectory(CWT)were used to analyze the main transport pathways and potential source regions of PM_(10),and also revealed the potential source distributions and contribution levels of PM_(10)in different seasons in Korla during the study period.The results showed that the annual average values of PM_(2.5)and PM_(10)in 2015-2020 in Korla were 47.7±20.0μg·m^(-3)and 162.2±102.4μg·m^(-3),respectively,exceeding the national annual average secondary concentration limits by 132%and 36.3%.The PM_(10)was the main pollutant.The PM_(2.5)/PM_(10)value was the lowest in spring(0.29)and the highest in winter(0.47),and the overall PM_(2.5)/PM_(10)value showed a decreasing trend.The airflow transport path mainly came from the short west wind flow,followed by the east irrigation airflow from Turpan Basin.The Tarim Basin was the main contributing source area of particulate matter in Korla throughout the year,and the contribution level of particulate matter concentration was higher in spring and winter,and lower in summer and autumn.It is important for Korla to prevent the impact of sand and dust aerosols from the Tarim Basin on air quality,followed by the east-flooding airflow from the Turpan Basin and the west-flooding airflow from Central Asia.