Temporal And Spatial Changes Of Air Quality In Three Cities Of Hohhot Baotou And Ordos And Analysis Of Influencing Factors

The Party Central Committee with Comrade Xi Jin Ping as its core since the eighteen party has attached great importance to the construction of socialist ecological civilization,and atmospheric environmental protection is an important part of the construction of ecological civilization,which is related to people’s health and happiness.As the"Golden Triangle"of Inner Mongolia,the air quality of Hohhot,Baotou and Hubei is directly related to the air quality of the whole region.Based on the air quality monitoring data of Hohhot,Baotou and Ordos from 2016 to 2020,this thesis uses Excel,Arc GIS10.2 and SPSS23.0 to make statistical analysis on the data,studies the temporal and spatial changes of air quality,explores the influencing factors of air pollution,and puts forward practical guiding significance for the improvement measures of air quality of the three cities in the future.The results are as follows 1.From the perspective of time dimension,the air quality composite index of Hohhot and Baotou showed a downward trend year by year in the study year,while the overall air quality of Ordos was low and stable,and the air quality of Ordos was significantly better than that of Hohhot and Baotou.PM₁₀,PM_2.5and O₃are the most frequent pollutants in Hohhot and Baotou,and PM₁₀is in Ordos,The frequency of PM10 as the primary pollution is more than 58%every year.In five years,only SO₂and CO in Hohhot did not exceed the secondary standard limits,and the concentrations of all pollutants reached the peak in 2017.The values of SO₂,CO and O₃in Baotou city did not exceed the standard in 5 years.In Ordos,only PM₁₀exceeded the standard.In the seasonal change,the comprehensive index of the three cities is low in summer,followed by spring and autumn,and the highest in winter.The seasonal variations of PM_2.5,PM₁₀,SO₂,O₃and CO were the lowest in summer,followed by spring and autumn,and the highest in winter,while the seasonal variation of O₃was opposite.The seasonal variation of NO₂concentration was the lowest in summer,followed by spring and winter,and the highest in autumn.In the monthly change,the monthly change of the air quality composite index of the three cities showed a U-shape,the monthly change of PM₁₀,PM_2.5,SO₂,NO₂and co showed a U-shape distribution,while O₃showed an inverted U-shape distribution,and the peak concentration of O3appeared from June to August.The maximum value in July was 142μɡ/m³,the smallest in December is42μɡ/m³.2.From the perspective of spatial dimension,the spatial distribution of pollutants in Hohhot is higher in the north than in the south,and higher in the West than in the East.The air quality at the junction of the four districts is poor.Among the four districts,Saihan district has the best air quality.From the perspective of AQI,the air quality of Qingshan District is the best in Baotou City,and the junction of Donghe,Jiuyuan and Qingshan District is the most polluted.The air quality in Kangbashi district is better than that in Dongsheng District.3.Among the natural factors,temperature and precipitation have significant effects on PM₁₀,PM_2.5and O₃,while sunshine logarithm has significant effects on O_3,The correlation coefficient is 0.487**in Hohhot and 0.769**in Baotou.Among the social factors,the green coverage area and green coverage rate of the built-up area are negatively correlated with the five selected indicators.