2014-2021年德阳大气颗粒污染物特征及案例分析

Characteristics and Case Analysis of Particulate Pollutants in Deyang from 2014 to 2021

利用德阳2014—2021年气象观测数据和大气颗粒污染物数据,分析了PM_(2.5)和PM_(10)浓度变化特征及其与气象要素相关性,并以2017年1月25—28日PM_(2.5)污染过程为案例,开展了污染过程的气象条件和后向轨迹分析。结果表明:(1)2014—2021年德阳PM_(2.5)和PM_(10)浓度呈下降趋势,二者浓度的日最大值、最小值分别出现在11时、17时,月均浓度都表现出“夏低冬高”的特征。(2)德阳四季PM_(2.5)和PM_(10)日均浓度均与降水量及地面风速呈显著负相关关系,而与相对湿度、气温、气压的相关性则存在季节差异。(3)地面均压场、气压梯度小、风力微弱的静稳天气条件以及上游污染物的输入是导致此次重污染形成和加重的主要因素。

Based on the meteorological observation data and particulate matter data of Deyang during the period from 2014 to 2021,the variation characteristics of PM_(2.5)and PM_(10)concentration and the correlation with meterological factors were analyzed.Taking the pollution process of PM_(2.5)from January 25th to 28th,2017 as example,the weather condition and backward trajectory were carried out.The results showed that:(1)The concentrations of PM_(2.5)and PM_(10)in Deyang showed a downward trend from 2014 to 2021.The daily maximum and minimum concentrations of PM_(2.5),PM_(10)appeared at 11:00 and 17:00,respectively.The monthly average concentration showed the characteristics of"low in summer and high in winter".(2)The daily average concentrations of PM_(2.5),PM_(10)in all seasons were significant negatively correalted with precipitation and surface wind,while there were seasonal differences in the correaltion with relative humidity,pressure,temperature.(3)The stable weather conditions such as continuous uniform pressure field,small pressure gradient,light breeze and the input of upstream pollutants were the main factors leading to the formation and aggravation of this heavy pollution event.