Study On The Spatial And Temporal Distribution Of Atmospheric Particulates And The Influencing Factors In The Main Urban Area Of Urumqi

Urumqi is one of the most important cities in western China,and also the important gateway for exchanges and cooperation between China and central Asian countries.However,excessive development has led to serious environmental pollution problems in Urumqi,in which,the pollution of atmospheric particulates is particularly serious.It is extremely necessary to explore the spatial and temporal variation characteristics of atmospheric particulate pollution in Urumqi and its influencing factors.This paper collects and organizes air pollutant concentration data and meteorological data of seven air pollutants monitoring stations distributed evenly in Urumqi built-up area from March 2016 to February 2017,and makes research on the spatial and temporal variability of atmospheric particulates(PM_2.5 and PM₁₀)in Urumqi built-up area in different time and space scales and their relationship with gaseous pollutants and meteorological factors by using methods of mathematical statistical analysis,kriging spatial data interpolation,backward trajectory analysis,PSCF analysis and CWT analysis.The results are as follows:?1?Atmospheric particulates(PM_2.5.5 and PM₁₀)show obvious change rule in time,both of which have the lowest value in July and the highest value in January the following year.Monthly average concentration of PM_2.5 and PM₁₀0 from April to October is obviously lower than that from November to March the following year,when the dispersion degree of the concentration is very high,and the period of which basically coincides with the heating period?10 October-10 April?.PM_2.5/PM₁₀ from November to March the following year is higher than that from April to October,whose ratio is more than 0.5,and it can be seen that fine particle pollution is more serious when heating;atmospheric particulate matter has obvious weekend effects;the hourly change trend of PM_2.5 and PM₁₀ presents a three-peak distribution.?2?Atmospheric particles(PM_2.5 and PM₁₀)have obvious spatial distribution.The distribution of the concentration of PM₁₀ and PM_2.5 is similar all year around and the pollution in the northwestern Urumqi is serious;in spring,the distribution of PM₁₀ and PM_2.5 is different,and the high value regions of PM_2.5 are mainly distributed in the northwest,while the concentration of PM₁₀ is higher than that in the middle;in summer,the concentration of each site changes little and is low;in autumn,the distribution of PM₁₀ and PM_2.5 is similar,and the pollution is relatively low in the northwest and higher in the east;in winter,the distribution of PM₁₀ and PM_2.5 is slightly different.The distribution of PM_2.5 is higher in the north than that in the south,and the high value regions of PM₁₀ are distributed in the northeast.?3?The regional transport trajectory is affected by the season.In spring,air mass movement mainly comes from the west and the northwest.The source in summer is mainly in the middle east of Kazakhstan.The source of air mass movement in autumn is Kazakhstan and in winter is mainly in China.From PSCF and CWT analysis,the transportation of local sources and neighboring countries has contributed to the PM_2.5 of Urumqi.?4?Atmospheric particulates(PM_2.5 and PM₁₀)is related with height and degree of correlation in seasonal mode respectively is:spring<summer<autumn<winter;PM_2.5 is positively correlated with NO₂,and R respectively is:spring?0.85?>summer?0.78?>autumn?0.77?>winter?0.76?;the correlation between PM_2.5 and O₃ is not strong;R of PM_2.5and CO is respectively:autumn?0.87?>spring?0.86?=winter?0.86?>summer?0.46?;PM_2.5is positively correlated with SO₂ and degree of correlation in seasonal mode respectively is:summer?0.87?>spring?0.7?>winter?0.62?>fall?0.56?.?5?PM_2.5 is affected by meteorological factors.For the whole year,PM_2.5 are positively correlated to pressure and humidity and negatively correlated with temperature and wind speed.In the seasonal pattern,excluding the part that did not pass the significant test,the correlation was opposite in summer to other seasons.That is to say,PM_2.5 was negatively related to air pressure and humidity,and positively related to temperature and wind speed.