Evolution Characteristics Of Air Pollution In Harbin And Its Response To Land Cover Change

?With the continuous advancement of urbanization,the contradiction between the demand for land use of social development and atmospheric ecological governance has deepened,and the dynamic changes of atmosphere caused by land cover transformation have become more and more complex.Therefore,it is of great significance to analyze and study the dynamic change law of air pollutants in Harbin and the relationship between land cover transformation and ecological construction.In this paper,the data of air pollution concentration and land cover change in Harbin were selected to analyze the time distribution characteristics of air pollutants from 2017 to 2021.At the same time,Arc GIS was used to map the spatial change trend of land cover types,and combined with the evolution characteristics of land use cover from 2017 to 2021,the law of land cover transfer in Harbin was analyzed.The results of the study showed that:（1）From January 2017 to 2021,except for 2019 to reach the peak of the range,the concentration of air pollutants in Harbin showed a trend of stage decline.Among them,SO₂concentration decreased by 51.30%year-on-year,CO concentration decreased by7.22%year-on-year,NO₂concentration decreased by 31.28%year-on-year,and PM_2.5concentration decreased by 12.75%year-on-year.（2）The spatial changes of land cover show that from 2017 to 2021,the proportion of green area in the center of Harbin increased,and the suburban areas were mainly cultivated land and forest land,and the change was±35 km²within 5 years.The area of urban grassland and forest land continued to expand,increasing by 18.15%,the area of transportation land increased by 1.13%,and the area of industrial land decreased by21.70%.This shows that industrial and mining uses are gradually shifting to green land.（3）In the response analysis of air pollution and land cover,the Pearson correlation coefficient matrix showed that cultivated land had the highest correlation with NO₂,with a correlation coefficient of-0.87.Except for NO₂,the concentrations of the three air pollutants were significantly positively correlated with the land area of energy enter prise,and the more serious the air pollution,the stronger the correlation with industrial land.Therefore,land use by energy enterprises is the main driver of air pollution.In summary,this study reveals the relationship between the dynamic changes of air pollutants and land cover transformation in Harbin.The research results are of great significance for guiding regional urban development and ecological construction,and provide a scientific basis for formulating effective environmental protection and land planning policies.