南昌市中心城区土地集约利用水平对主要大气污染物的影响

当前,我国城市化进程已由外延式的扩张逐步转变为内涵式发展.集约利用土地资源,构建“紧凑城市”变得越来越迫切.然而,集约利用土地意味着更少的土地资源承载更多的城市要素,人们对环境污染,特别是大气环境污染会变得越来越敏感,研究城市土地集约利用水平对大气污染的影响具有重要意义.本研究以南昌市中心城区为研究区,采用普通克里格插值法模拟6种主要大气污染物(PM_2.5、PM₁₀、SO₂、NO₂、CO、O₃)浓度的空间分布,基于土地利用样本区,选择综合容积率、建筑密度、人口密度等16个土地集约利用水平相关变量,采用偏最小二乘回归与通径分析方法,定量分析土地集约利用水平对大气污染物的影响.结果表明: 土地集约利用水平相关变量与PM_2.5和PM₁₀的相关性最强,其次是O₃和NO₂,与SO₂和CO的相关性最弱;不同土地利用样本区土地集约利用水平变量与6类主要大气污染物的相关性强弱依次为:居住区>教育区>商业区>工业区.土地集约利用水平越高,对大气污染物的影响越大,其中PM_2.5与PM₁₀的影响最大,其次是O₃,NO₂的影响较小.各土地利用样本区土地集约利用水平对大气污染物的直接影响、间接影响和综合影响基本相当,但总体而言,土地集约利用水平的直接影响大于间接影响,其中,居住区土地集约利用水平的综合影响最大,其次是商业区,最小的是教育区.本研究为土地集约利用对大气环境的影响研究提供了新的思路,为解决紧凑城市大气环境问题提供了一定的参考.

Influence of land intensive use level on main atmospheric pollutants in the central urban area of Nanchang City,China.

At present, urbanization has gradually changed from denotative expansion to connotative development in China. It is urgently needed for intensive use of land resources and the construction of “compact city”. However, intensive land use means less land resources to carry more urban elements, therefore people will become more and more sensitive to environmental pollution, especially atmospheric pollution. It is of great significance to study the influence of intensive land use on atmospheric pollution. Taking the central urban area of Nanchang City as a case, this study simulated the concentration of the six main atmospheric pollutants i.e. PM_2.5, PM₁₀, SO₂, NO₂, CO and O₃ by ordinary kriging interpolation firstly. Then, sixteen intensive land use variables, including the volume ratio, building density, population density, were analyzed with the partial least squares regression and path analysis in order to reveal the effects of intensive land use level on the atmospheric pollutants. The results showed that the correlations between intensive land use level and PM_2.5, PM₁₀ 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. The more intensive the land use was, it had greater impacts on the atmospheric pollutants. The greatest effect was on PM_2.5 and PM₁₀, followed by O₃, and the least effect was on NO₂. The direct, indirect, and integrated influences of intensive land use on atmospheric pollutants were generally equal. Overall, the direct influence of the intensive land use level was greater than the indirect one, among which the influence of the intensive land use level of the residential area was the strongest, followed by the business area, and the education area least. This study provided a new perspective on studying the influence of intensive land use on atmospheric environment, which would provide some reference to solve the atmospheric problems in compacted city.