Research On The Temporal-spatial Change And Major Meteorology Influencing Factors Of PM₁₀ And PM_2.5 Pollution In Major Cities Innortheast Regions

With the rapid development of economy,industrial emissions of air pollutants,motor vehicle exhaust emissions,and the emissions of coal-fired heating in winter in cities make the air pollution worse and worse which has become a larger burden to our country's economic and social development.Since 2013,the main pollutants in the three northeastern provinces are PM₁₀,the proportion of PM_2.5 in PM₁₀ is larger and the damage is greater.PM₁₀ and PM_2.5 pollution are more prominent in winter,which needs the research into the rules and regulatory mechanisms of air pollution.This paper mainly analyzed the situation of PM₁₀ and PM_2.5 pollution in the air of32 major cities in the three northeastern provinces as well as their temporal and spatial features and gravity migration.Meanwhile,it analyzed the influence of meteorological factors on the concentration of PM₁₀ and PM_2.5based on the synoptic meteorological data.It also analyzed the influence of meteorological factors on pollutants according to the urban central heating area in winter for the purpose of provide basis on pollution prevention and control of PM₁₀ and PM_2.5in three provinces in Northeast China.The results showed that from the time variation,in 2015,in time series,PM₁₀ and PM_2.5 are relatively serious in January,February,November,and December,and in March,April,and October less,and in May,June,July,August and September the pollution is the least.In space variation,since January 2015,with the change of time,PM₁₀ pollution has an obvious offset direction in its moving track.In January,it shifted to the east end?125.23°E,125.23°N?,and shifted to the southernmost end and the westernmost end?124.69°E,124.69°N?in March,and it shifted to the northernmost end in July?125.04°E,125.04°N?,which shows that there are regional differences in PM₁₀ pollution in the northeast three provinces;PM_2.5 pollution in January shifted to the east end?125.31°E,125.31°N?,and to the northernmost end in July?125.02°E,125.02°N?,and to the southernmost end,and the most western end?124.72°E,124.72°N?in September,which shows that there are also regional differences in PM_2.5pollution in the northeast three provinces.The global spatial correlation of PM₁₀ and PM_2.5 pollution is weak while the autocorrelation is gradually increasing in northeast three provinces in China and the overall trend of PM₁₀ in 2015 global Moran's I high index for November is 0.1951,the lowest for July is-0.0990,which showed that the concentration change of PM₁₀ is changing with the seasons;while In 2015,the global Moran's I index peaked at 0.2716 in November,and the lowest is-0.1916 in July.This tendency shows:the PM₁₀ and PM_2.5 are affected heavily by the seasons in 12 months in the three northeast provinces in China in 32maior cities,and they are changing with seasons.The analysis is carried out on the basis of the overall spatial autocorrelation,which can be seen from the LISA,the pollution is unbalanced on the whole.The high point is focused on Chen Yang City,Liao Ning Province and Chang Chun City,Ji Lin Province and cities around,while the low point is on the northern border,Hei He City.The GWR model analyzed the effects that meteorological factors had on the concentration of PM₁₀ and PM_2.5.It showed that the relative humidity was positively correlated with the concentration of PM₁₀ and PM_2.5.The temperature was positively correlated with the concentration of PM₁₀ and PM_2.5.The wind level was negatively correlated with the concentration of PM₁₀ and PM_2.5.Coal heating in winter was also an important reason of increasing PM₁₀ pollution.The study has shown that the pollution of PM is the most serious,especially in high temperature,high humidity,and low wind conditions as well as in winter.Therefore,the establishment of the city PM₁₀,PM_2.5forecasting system should be based concentration of PM₁₀ and PM_2.5 and meteorological factors in the city to establish different forecasting systems.