影响湖南省空气质量指数的主要气象因子分析

Analysis of the Dominant Meteorological Factors of Air Quality Index in Hunan Province

为了落实《湖南省大气污染防治攻坚行动工作方案》对空气质量预报精细化的要求,本研究基于湖南省主要城市2015—2022年间的空气质量数据和气象要素数据,采用统计分析、相关分析、主成分分析法(PCA)等方法,分析了湖南省空气质量指数(AQI)与气象条件之间的关系,提取了影响湖南省不同等级AQI的主要气象因子,并分析了不同等级污染天气的主要气象影响因子。结果显示:(1)在研究期内,湖南空气质量优良天数优于全国平均水平,污染天数分布存在显著的区域差异,部分城市没有出现过严重污染天气。(2)多个气象要素组合构成的气象因子共同对AQI产生影响,影响湖南省AQI的主要气象因子包括气温、水汽与日照组合、平均风速以及降水量;除严重污染天气外,气温因子是影响湖南AQI的首要因子。(3)单个气象要素与AQI之间的相关性较弱。(4)地形的影响使气象条件分布更复杂,而且主要影响AQI的气象因子存在区域差异,增加了AQI精细化预报的难度。

In order to realize the obligations of the"Hunan Provincial Air Pollution Prevention and Control Action Plan"for improving the air quality forecasting,this study investigated the correlation between the air quality index(AQI)and the meteorological conditions in Hunan province.Based on the air quality data and meteorological factor data from major cities in Hunan province from 2015 to 2022,the analysis was carried out using the statistical analysis,correlation analysis and principal component analysis(PCA).The relationship between the AQI and the meteorological conditions was investigated,the dominant meteorological factors influencing AQI levels were extracted,and the main meteorological influences on the different air pollution grades were also discussed.The results are as follows.(1)During the studied period,the number of good air quality days in Hunan province was higher than that of the national average state.There were significant regional differences in the distribution of polluted weather days,whilst some cities being exposed to less severe air pollution than others.(2)The combination of several meteorological variables exerted a collective influence on the AQI in Hunan province.The dominant meteorological factors affecting the AQI in Hunan province included the air temperature,combination of water vapour and sunshine,average wind speed and precipitation.(3)The correlation between the individual meteorological factors and the AQI was relatively weak.(4)Topography had a clear and distinct impact on the distribution of meteorological conditions,and there existed regional differentiation in the meteorological factors that mainly affected the AQI.This made the forecasting of AQI more difficult.