Influence of Terrain on Air Pollution Characteristics and Diffusion Conditions in Yichang
Meteorological and environmental monitoring data from 2016 to 2020 are used to analyze the influence of mountain terrain on the distribution and diffusion conditions of PM2.5,PM10 and O3 in Yichang,Hubei Province.The results show that:(1)Among the three pollutants,PM2.5 pollution is the most serious,the O3 pollution days are fewer than PM10 pollution days,but the pollution degree of O3 is higher than PM10.Affected by the topography,vegetation and human activities,the air pollution in the"Horn mouth"terrain of Yichang City is the heaviest.(2)Under the influence of terrain and regional transport,air pollution is easily formed in the"Horn mouth".In winter,particulate matter is the main pollutant,transported mainly from northeast and east directions.The potential source areas are mainly in the northern and eastern parts of Henan Provine as well as in Jingmen and Jingzhou.In summer,O3 is the main pollutant,and its pollution tracks are mainly from the south and east directions,with Jianghan Plain and Southern Yichang being its potential source areas.(3)Surface wind speed is negatively correla-ted to PM2.5 and PM10 concentrations,but when the average wind speed is faster than 3.3 m·s-1,the concentrations of PM2.5 and PM10 fluctuate greatly.Wind speed is positively correlated to O3 concentra-tion,but the correlation is negative when the average wind speed is>2.1 m·s-1.Under the influence of the"Horn mouth"terrain,the easterly wind is the main wind causing PM2.5 pollution in Yichang.With the terrain of the Yangtze River valley,the O3 concentration in Yichang urban area might be raised when northwesterly wind and easterly wind blow.(4)Precipitation has a wet removal effect on pollutants,and it is negatively correlated to pollutant concentrations.However,when precipitation is less than 5 mm the PM2.5 concentration may increase exponentially.When precipitation exceeds 25 mm,the proportion of negative removal rate of PM10 might increase.The positive removal rate of O3 is higher than that of other pollutants,but the removal rate is not very high.
万方数据
维普
