Analysis Of Influencing Factors Of Ozone Spatial And Temporal Distribution In Wuhan Metropolitan Area Based On GTWR Model

The increase of near-surface ozone concentration not only threatens the ecological environment,but also harms human health.According to the ecological environment status bulletin of Hubei Province,ozone has become another important pollutant affecting the atmospheric environment quality in Wuhan metropolitan area after PM_2.5.However,there is a lack of research on ozone concentration and its influencing factors in Wuhan metropolitan area.Based on the pollutants and meteorological data of Wuhan metropolitan area from 2018to 2021,this paper analyzed the temporal and spatial distribution characteristics of ozone concentration and exceeding standard days in Wuhan metropolitan area.By means of GTWR model,Arcgis was used to conduct spatial mapping analysis on the regression coefficients of explanatory variables,so as to explore the leading factors affecting ozone concentration in Wuhan metropolitan area,which can provide data support and decision-making reference for atmospheric environmental governance in Wuhan metropolitan area.The main conclusions of the study are as follows:（1）In terms of the temporal and spatial distribution of ozone concentration in Wuhan metropolitan area,although the annual mean ozone concentration in 2018-2021 reached the lowest value of 92.07μg/m3in 2020,it showed a decreasing trend on the whole.Except for a slightly higher ozone concentration in 2019,the ozone concentration in Wuhan was at a low level in other years.The seasonal mean ozone concentration in city circle was summer>autumn>spring>winter.In terms of seasonal distribution,the ozone concentration in spring was higher than that in summer in 2020.In terms of spatial distribution of four seasons,the highest value in spring,summer and autumn was in Xiantao city,Huanggang City and Tianmen city respectively,and there was no high value in winter compared with other seasons.The monthly variation of ozone concentration showed an irregular"M"pattern,Peak and trough values appear in July.（2）Spatial and temporal distribution of ozone exceeding standard days in Wuhan metropolitan area from 2018 to 2021,the number of ozone exceeding standard days was the most in 2019 and the least in 2020.Except for 2018,when the number of days exceeding the standard was less,Wuhan ranked the top in all years,with a total of 139 days exceeding the standard for four consecutive years,ranking the first among cities in the metropolitan area.In terms of pollution levels,Xiaogan city was severely polluted one day in 2018,and there was no severe pollution in other years.Seasonal distribution,Wuhan metropolitan area has no exceeding number of days in winter,and has the most exceeding number of days in spring of2020,and the most exceeding number of days in summer in other years.The number of days exceeding the monthly standard generally concentrated in June and September.（3）In the analysis of the influence of meteorological factors on ozone concentration in Wuhan metropolitan area,air temperature has a strong positive effect on ozone,total precipitation has a negative effect on ozone,and wind direction has positive and negative effects on ozone,the effect of atmospheric pressure on ozone was only negative in 2018,and positive in the other years.In the relationship between meteorological and ozone seasonal variation,the positive effect of air temperature on summer was 0.727,which was less than1.236 in spring and 1.027 in autumn.（4）In the analysis of the relationship between ozone concentration and other pollutants in Wuhan metropolitan area,PM_2.5has a strong negative relationship with ozone,and the trend of negative relationship is enhanced in time series.NO₂and CO are negatively correlated with ozone concentration,and the negative relationship between NO₂and ozone was stronger than that of CO.