湖南省大气污染特征及气象影响分析

Analysis of Air Pollution Characteristics and Meteorological Impact in Hunan Province

为深入探究湖南省大气污染过程变化特征及气象条件对不同首要污染物的影响,利用2015—2021年湖南省14个市州的大气环境监测数据及气象观测数据,分析研究了68次污染过程的持续时长、分布特征等,并根据污染来源分析结果、传输路径分析结果,结合地形特征,进行了污染影响区域划分,对不同首要污染物的气象因子反馈机制进行了细致剖析。结果表明:湖南省大气污染过程以颗粒物污染为主,年变化特征呈现为单峰形,单次污染过程持续时长一般不超过3 d;3条主要的污染物传播路径均是由湘北地区进入长株潭城市群;污染来源以本地积累为主,外来输送与本地污染叠加次之;颗粒物污染主要受边界层稳定程度、逆温情况和近地面空气湿度的影响,臭氧污染则主要受紫外辐射、前体物浓度和扩散条件等的影响。

In order to explore the variation characteristics of pollution processes and the influence of meteorological conditions on different primary pollutants in Hunan Province,the duration and distribution characteristics of 68 pollution processes were analyzed by using the data of national control stations and meteorological observation data of 14 cities in Hunan Province from 2015 to 2021.According to the tracing analysis of pollutant census,the transport pathway and the terrain characteristics,the high impact area division was proposed,and made a detailed analysis of the feedback mechanisms of meteorological factors for different primary pollutants.The results showed that the pollution process in Hunan was dominated by particulate matter pollution,and the annual variation showed a single-peak variation with a general duration of no more than 3 days.The pollutants mainly affected Hunan in 3 paths from the northern Hunan region,with local accumulation dominating and the superposition of external transport and local pollution second.Particulate matter pollution was mainly affected by the stability of the boundary layer,temperature inversion and high humidity near the ground.Ozone pollution was mainly affected by the conditions suitable for photolysis of the premise brought by high temperature.