Research On The Impact Of Northern Sand And Dust Weather On Air Quality In Related Areas

Dust weather is one of the major meteorological disasters in the northwestern region of China and has received much attention.The Inner Mongolia and Sichuan Basins,as roads or areas affected by the movement of dusty weather along the North Road,Northwest Road and West Road,are greatly harmed.In the past,research on sand and dust weather mainly focused on synoptic and dynamic causes and meteorological hazards,and less attention was paid to their impact on environmental quality.Therefore,in this paper,we use the hourly and daily concentration data of particulate matter from 2014 to 2017 in the Inner Mongolia and Sichuan Basin related environmental protection monitoring stations and observation data of sand and dust weather during the same period to explore the concentration of particulate matter in dust weather from statistical analysis and case analysis.The aim is to raise awareness of the impact of foreign dust transport on air quality in relevant regions and provide scientific basis for comprehensive consideration of the impact of external sources and local sources on the air quality in relevant regions and its reasonable prevention and control.The main findings are as follows:1.The study shows that in the annual change of particulate concentration,the occurrence of dust weather in Inner Mongolia in the spring of 2014-2016 is increasing year by year.The mid-western region is a frequent area of dusty weather.Correspondingly,the annual change in particulate matter concentration in the central and western regions is higher than that in the east.The dust weather has a significant effect on the concentration of particulate matter.As the influence area of sand dust transport in Sichuan basin,the concentration of PM₁₀0 and PM_2.5.5 related to sand dust transport in the past 2014-2017 years is in the order of Eastern>Central>Southwest.Using the MICAPS ground meteorological data,the sand dust transport in the northern sand dust weather process will cause the occurrence of the dust weather in the Sichuan basin,and the particulate matter pollution in this area is obviously aggravated.If the annual concentration is divided into three periods for particle concentration comparison,the PM₁₀0 concentration during the dusty weather in Inner Mongolia was 69%higher than that during non-dust storms and 101%higher than other seasons.The concentration of PM_2.5.5 during the dust weather in spring was 29%higher than that in the non-dust period and 16%higher than that in other seasons,indicating that the effect of dust weather in spring on the concentration of PM₁₀0 in Inner Mongolia was generally stronger than that of PM_2.5.In addition,the percentage of PM_2.5.5 concentration in PM₁₀0 during the three time periods in the year also indicates that the ratio between the two is generally the spring dust period<non-dust season in spring<other seasons.In other words,although the concentration of PM_2.5.5 during the spring dust weather is also the highest in the whole year,the percentage of PM_2.5concentration in PM₁₀0 is the smallest during this period,which indicates that the sand dust transport is still coarse Particles dominate.2.The comparison of the concentration of particulate matter in different periods of the Sichuan Basin shows that the order of the concentration of PM₁₀0 in the three periods of the year is roughly:the period of floating dust in spring>other seasons>the period of non-dusting in spring;The concentration of PM₁₀0 in the 18 cities affected by the floating dust weather in the Sichuan basin is more than 120μg/m3,which is higher than the national standard of air quality first,indicating that the sand dust weather in the North has a significant influence on the local PM₁₀0 concentration.The concentration of PM_2.5.5 during the dusty weather in spring is higher than the percentage of non-flood dust during the spring,and only two sites are higher than100%.It also reflects that the effect of northern dust weather on the concentration of PM₁₀0 in the Sichuan Basin is greater than that of PM_2.5.The results are consistent with the concentration of particulate matter in 3 periods of Inner Mongolia.For the Inner Mongolia basin and Sichuan basin affected by sand dust weather,coarse particles are more affected by sand dust weather than fine particles.3.The results of analysis of individual dust weather cases show that the increase of PM₁₀0 concentration in the dust storm case in Inner Mongolia was between 2.3 and15.1,and the increase of PM₁₀0 concentration during the blow-up process is between0.8 and 5.6.The effect of dust storm on particulate matter pollution is significantly greater than that of the blow-up process.The result of the back track analysis of Sichuan basin shows that the affected sand dust in the related cities of the basin mainly originates in the Xinjiang area of China,which is usually transmitted to the Sichuan basin along Qinghai and Gansu over Qinling Mountains,which has a significant influence on the particulate matter pollution there,and is one of the main factors causing the heavy pollution process of the particulate matter in the Sichuan basin.In contrast to the situation in which the concentration of gaseous pollutants generally decreases during the impact of dust weather in northern China,the transport of dust in the north causes a slight increase in the concentration of gaseous pollutants in the Sichuan Basin,SO₂ and NO₂,and the concentration of CO does not change significantly.The cause of this phenomenon remains to be further studied in the future.