Study On Distribution Characteristics Of Main Atmospheric Pollutants And Their Relationship With Intensive Land Use Level In Built-up Area Of Nanchang City

At present,the process of urbanization and industrialization in China is advancing rapidly,and the process of urbanization in China has gradually changed from denotative expansion to connotative development.Intensive use of land resources and the construction of"compact city"have become more and more urgent.However,intensive land use means less land resources to carry more urban elements,therefore environmental pollution,especially atmospheric pollution will become more and more sensitive to people,the problem of land use and atmospheric pollution can not be ignored,and it is of great significance to study the distribution of atmospheric pollutants,the influence of land use and intensive land use on atmospheric pollution.Taking Nanchang city built-up area as a case,this study first simulated and analyzed the temporal and spatial distribution characteristics of the six main atmospheric pollutants i.e.PM_2.5,PM₁₀,SO₂,NO₂,CO and O₃basedonordinarykriginginterpolation.Secondly,each15sample residential,commercial,educational and industrial areas were selected according to dominated land use type,and 6 air pollutants concentration in each sample areas were averaged for four seasons.By means of multi-factor variance analysis,based on scientific assumption that the climatic and meteorological conditions were basically the same in the same season,this paper analyzed the effects of land use?expressed by sample area?on 6atmospheric pollutants.Finally,on this basis,the volume ratio,building density,population density et al totally sixteen intensive land use variables were selected to do the partial least squares regression and path analysis in order to analyze the effects of intensive land use level on the atmospheric pollutants based on the land use sample area.The results showed as follows.?1?The concentration of 6 atmospheric pollutants in the study area had obvious temporal and spatial distribution characteristics.The concentration of PM_2.5,PM₁₀,SO₂,NO₂ and CO was the highest in winter,followed by spring,autumn and summer.The concentration of O₃ was the highest in summer,followed by spring,autumn,and winter.In addition,The concentration of PM_2.5,PM₁₀,SO₂,NO₂ and CO showed a decreasing trend of urban center to suburb,while The concentration of O₃ was opposite.?2?The effects of climatic and meteorological conditions?expressed by seasons?and land use?expressed by sample area?on PM_2.5,PM₁₀,SO₂,NO₂,CO and O₃ were significant,while the effect of their interaction on NO₂ and O₃ was not significant.The interaction effect on the remaining 4 pollutants was significant.?3?The impact of urban land use on atmospheric pollutants was not as significant as the climatic and meteorological conditions expressed by the seasons,urban land use was also an important factor affecting atmospheric pollutants.?4?The correlation between intensive land use level and PM_2.5,PM₁₀0 were the strongest,followed by O₃ and NO₂,and the weakest correlation was between intensive land use level and SO₂,CO.The sequence of the correlation between intensive land use variables and the six main atmospheric pollutants in different sample areas was residential area>education area>business area>industrial area.?5?The more intensive the land use,the greater the impact on the atmospheric pollutants.The greatest effect was on PM_2.5.5 and PM₁₀,followed by O₃,and the least effect was on NO₂.?6?The direct,indirect and the integrated influence of intensive land use on atmospheric pollutants were basically equal,but overall,the direct influence of the intensive land use level was greater than the indirect influence,among which the influence of the intensive land use level of the residential area was the strongest,followed by the business area,the education area.This paper can provide a new paradigm for the study of atmospheric environment effects of land use/land cover.Moreover,it explores a feasible way to reduce atmospheric pollution through urban land use optimization,and it provides a new idea to study the influence of intensive land use on atmospheric environment,which can provide some reference to solve the atmospheric problems in compacted city.