大气污染物浓度变化特征及潜在源分析——以乌鲁木齐为例

Concentration characteristics and potential source of atmospheric pollutants:A case study in Urumqi

对2017年乌鲁木齐市的气象参数及大气污染物的浓度进行了统计分析,探究了大气污染物的浓度变化特征,运用轨迹聚类分析、潜在源贡献函数(PSCF)和浓度权重轨迹法(CWT)研究了乌鲁木齐市PM_(2.5)的传输路径和潜在源区。结果表明:乌鲁木齐市大气超标污染物主要为PM_(2.5)和PM_(10),除O_(3)外各污染物的浓度均是采暖期高于非采暖期,温度低、风速小、相对湿度大、乌鲁木齐市三面环山、逆温天气是造成采暖期颗粒物污染严重的重要原因;PM_(2.5)区域传输主要来自西北方向,在采暖期受来自尼勒克县、沙湾县、呼图壁县、阜康市的短距离传输气团影响很大;PM_(2.5)潜在源区主要集中于阜康市、和静县、沙湾县、昌吉市、沙湾县、吉木萨尔县、玛纳斯县,乌鲁木齐市PM_(2.5)浓度同时受外来污染物输入和本地污染源排放的影响。

Meteorological parameters and pollutant concentrations in Urumqi,China,in 2017 were used to study the concentration characteristics of atmospheric pollutants and the influence of meteorological factors on pollutants.Trajectory cluster analysis,potential source contribution function analysis,and the concentration weighted trajectory method were used to assess the transport pathways and potential sources of PM_(2.5).The findings revealed that the most serious pollution was from PM_(10) and PM_(2.5).During periods of heating,the concentrations of atmospheric pollutants,apart from O_(3),were higher than those during periods where there was no heating.The heavy pollution of atmospheric particles(PM_(2.5) and PM_(10))during heating periods was ascribed primarily to low temperature,low wind speed,high relative humidity,special topographies,and temperature inversion.PM_(2.5) in Urumqi was transported mostly from the northwest,the short distance pathways of Nileke Town,Shawan Town,Hutubi Town,and Fukang City had greater influence on Urumqi during heating period.The main potential sources of PM_(2.5) were determined as being Fukang City,Hejing Town,Shawan Town,Changji City,Shawan Town,Jimusaer Town,and Manasi Town.External transport and native sources of pollution also had a great impact on the level of PM_(2.5) in Urumqi.