Study On The Characteristics And Distribution Of NO₂ Pollution In Anhui Province

Although air pollution has been greatly reduced in recent years,the pollution index is still relatively high.Nitrogen dioxide pollution in Anhui Province during the13 th Five-Year Plan period showed an upward trend and then a downward trend.In order to better prevent and control nitrogen dioxide pollution,this study uses data during the 13 th Five-Year Plan period,combined with meteorological data,motor vehicle flow data,and meteorological trajectories to study the characteristics of nitrogen dioxide pollution in Anhui Province and analyze its sources.The pollution of NO2 in Anhui Province is low in spring and summer and high in autumn and winter.Among the three regions in northern Anhui,the air quality level is lightly polluted the most,but the NO2 pollution is relatively moderate.NO2 pollution is the highest in central Anhui.The difference between southern Anhui and northern Anhui is relatively small,which is lower than that of northern Anhui in autumn and winter in southern Anhui,and higher than northern Anhui in spring and summer.There will be weekend effects and anti-weekend effects in cities,and the reason is related to the number of weekend motor vehicle trips around city sites.The external sources of pollution in Anhui Province mainly come from the northern regions of Beijing-Tianjin-Hebei and Shandong.Air temperature and accumulated precipitation have a significant effect on reducing NO2 pollution,while wind speed and relative humidity have no significant effect on reducing NO2 pollution.Among the temperature and cumulative precipitation,the temperature is more important than the long-term impact on pollution,and the cumulative precipitation is more important than the timeliness.As for the relative humidity,65%-75% is the humidity during normal pollution,and 75%-85% is more prone to high or low pollution.Large and small vehicles will cause different levels of pollution to the environment.Due to the large number of small vehicles,the emissions of environmental pollution are more than that of large vehicles.The actual pollution of a city by traffic flow varies according to the degree of development of different cities.