基于小波变换的武汉市PM2.5、PM10与臭氧污染特征

为验证城市空气污染物排放及协同控制后的周期性规律,利用小波变换对武汉市2013～2020年共计2421d的逐日PM_2.5、PM₁₀及臭氧浓度数据进行分析.结果表明:可吸入颗粒物污染情况逐年改善,PM_2.5浓度年均值由80.5μg/m³降至45.3μg/m³,超标比例由44%降至11%;PM₁₀浓度年均值由113.6μg/m³降至72.6μg/m³,超标比例由22%降至2%.臭氧污染未有明显改善,浓度年均值在90～100μg/m³间波动.PM_2.5、PM₁₀与臭氧浓度均表现出明显的周期性,PM_2.5浓度主周期300d、次周期140d左右;PM₁₀浓度主周期300d、次周期125d左右;臭氧浓度主周期300d、次周期143d左右.PM_2.5与PM₁₀的周期与位相均相...

Studies on characteristics of PM2.5, PM10 and ozone pollution in Wuhan based on wavelet transform

In order to verify the periodic law after the cooperative control of urban air pollutants emission, wavelet transform was used to analyse daily PM_2.5, PM₁₀ and ozone concentration data of 2421 days (d) from 2013 to 2020 in Wuhan. The results are as follows: Inhalable particulate matter pollution had been reduced year by year. From 2014 to 2019, the annual average concentration of PM_2.5 had reduced from 80.5μg/m³ to 45.3μg/m³, and that of PM₁₀ had reduced from 113.6μg/m³ to 72.6μg/m³, which means the excessive rate of PM_2.5 was reduced from 44% to 11%, and that of PM₁₀ was reduced from 22% to 2%. The ozone pollution had kept unabated, with the annual average concentration of ozone fluctuating between 90μg/m³ to 100μg/m³. The concentration of all three kinds of pollutants displayed clear periodicity. PM_2.5, PM₁₀ and ozone concentration displayed with a same primary period of 300d. On the contrary, the secondary period of the three pollutants were 140d, 125d, and 143d respectively. PM_2.5 and PM₁₀ had similar periods and phases, which indicates that pollution behaviours of both particulate matters are consistent. Furthermore, the concentration of the three pollutants had a positive correlation was revealed in short period (0~64d), whereas a negative correlation in long period of about 300d.