杭州城市空气污染物空间分布及其影响因子的定量分析

A quantitative analysis on spatial distribution of the pollutants in the urban air and their impact factors based on geostatistics and GIS: A case study of Hangzhou city

以乡镇、街道为基本空间统计单元,基于地统计方法、GIS和遥感技术绘制和计算了杭州城市人口密度、道路面积比例、建设用地比重、NDVI和地表温度的空间图层,并应用GIS空间数据相关分析和空间叠加方法,定量评价了SO2、NO2、O3的空间分布与城市人口密度、建设用地比重、道路用地比例、地表温度等影响因子的空间相关程度和总体污染水平的分布特征。结果表明:NOX的空间分布受道路比例、地表温度、城镇建设用地、人口密度的影响程度最大,SO2次之,O3最小。SO2受工业用地分布影响较大,O3为二次污染物,其空间分布受其他因素影响相对较小。杭州市室外空气的总体污染程度,主要集中在上城、下城、拱墅,江干区次之,西湖区污染程度较轻。城市空气污染物浓度空间分布及受其他因素影响程度的定量分析可以为不同城市地域有针对性地制定合理的空气污染缓减对策提供科学依据。

Urban air pollution is produced in the process of all kinds of human activities such as industrial production, living and traffic. Rapid urbanization processes result in the increasing of the kinds and concentration of the pollutants in the air of built-up area. By taking streets and towns as the basic spatial analysis unit, the concentrations of sulfur dioxide, ozone nitrogen dioxide and some factors influencing urban air pollutions in Hangzhou such as population density, percentage of road area, built-up area, surface temperature and NDVI are mapped and computed based on ordinary kriging, GIS and RS in this paper. The relativity between the concentration of three pollutants and their influencing factors are quantitatively evaluated by integrating spatial correlation analysis, and the characteristics are obtained by overlay of the ranked data layers. The results show that in downtown （including Shangcheng, Xiacheng, Gongshu）, Xihu and Jianggan, the spatial relativity between three air pollutiants and their impact factors have spatial heterogeneity. Among the three pollutions, the spatial distributiants of NO2 is firstly influenced by the distribution of impact factors; SO2 is secondly, and O3 is thirdly. The overall degree of air pollution outdoor in Hangzhou is the highest in downtown and the lowest in Xihu. The strong spatial heterogeneity is the main characteristic of the distribution of the air pollutants in the built-up area. The two main aims of the quantitative analysis on spatial distribution of urban air pollutions and their influence from other factors are to provide the scientific basis for establishing pertinently the reasonable countermeasures to mitigate urban air pollution and putting forward the effective measures for the prevention and control of air pollution.