Study On Air Quality Change Characteristics Of Different Types Of Cities In Heilongjiang Province

Since China’s rapid development,with the continuous expansion of urban economy and industrialization,urban environmental quality has suffered a huge impact.Data from various regions show that the degree of air pollution in China is increasingly severe,and even has affected people’s normal production and life.Air pollution has directly or indirectly caused a variety of diseases,such as respiratory problems,etc.,serious even life-threatening,environmental crisis has given us a wake-up call.How to solve the problem of air pollution has become the focus of the government and environmental departments,and has attracted the attention of many scholars.Research on air quality in urban areas is conducive to accurately understanding the current situation of urban air pollution and providing some feasible Suggestions for further strengthening air pollution prevention and control and improving the quality of our living environment.Considering the city function type factors influence the change of air quality,in this paper,a fusion of different cities in selecting target city function types,with different types of city in Heilongjiang province as the research object,the choice of five different types function cities,the political and economic center city of Harbin,coal industrial Shuangyashan,industrial city of Daqing oil,forest ecological city of Yichun,and agricultural of Suihua,according to the March 1,2016 to April 20,2018 air quality data and meteorological data,explore five urban air quality objectives,and discuss its influencing factors.Main research contents and results are as follows:（1）through the statistical analysis of the frequency and variation rules of six air pollution factors in several cities,it is concluded that except Harbin,PM_2.5,PM₁₀0 and O₃account for the largest proportion of primary pollutants in the other four cities,accounting for 13.01%-37.37%,5.95-20.76%and 3.53-27.84%,respectively.The key factors affecting the air quality in Harbin are more nitrogen oxides than other cities,including NO₂,PM_2.5,PM₁₀0 and O₃.Finally,PM_2.5,PM₁₀0 and O₃ were selected as the research objects to establish the air quality index system.（2）based on the AQI values of the five cities in the study period,most of the cities were in the excellent and good pollution levels stipulated by the national quality standards,while a few were in the mild and moderate pollution,and the severe and severe pollution weather was rare.Yichun’s air quality was mostly in the excellent level.（3）the change rule of particulate matter in the seasonal period is high in winter and low in summer,while O₃,on the contrary,is high in summer and low in winter.The average monthly concentration of PM_2.5in all cities is mainly between 10μg/m³-80μg/m³,which meets the national level 2 standard.Most of Yichun can reach the level 1 standard.The monthly changes of the concentrations of the three major pollution factors are more or less different among cities,and the overall trend is relatively close.（4）except Shuangyashan city,the heating period has a great influence on the concentration of atmospheric particulate pollutants in the other four cities.In Shuangyashan and Suihua,the concentration of particulate matter exceeds the standard seriously during the non-heating period,which indicates that the main source of atmospheric particulate pollutants in the two cities is not only soot emissions,but also dust and other factors.Through the concentration comparison of pollution factors,soot emission is an important reason for the increase of atmospheric particle concentration whether in the heating period or not.（5）urban functional types have a great impact on regional air quality,which is mainly reflected in the proportion of primary pollutants,air quality index value and time variation of primary pollutant concentration.The automobile exhaust which can produce nitrogen oxides has a great influence on Harbin.The main effect of industrial structure on Shuangyashan and Suihua is that the concentration of PM₁₀0 is high.（6）meteorological conditions play an important role in air pollution,the most important of which is reflected in the influence of temperature index on pollution factor concentration.Data research shows that temperature has a significant influence on PM_2.5and PM₁₀0 concentration,which is in direct proportion.Humidity affects the concentration of O₃ index.O₃ concentration in Daqing city is also affected by wind speed.Other cities were not significantly affected by wind speed.