中国城市PM_(2.5)浓度时空特征及其影响因素

The Spatial-temporal Characteristics of PM_(2.5) Concentrations in Chinese Cities and the Influencing Factors

在科学识别城市建成区的基础上,运用探索性空间分析和空间计量模型,分析了2000–2015年中国城市PM_(2.5)浓度的时空特征及其影响因素。结果表明:2000–2015年中国城市PM_(2.5)浓度呈倒“L”型增长,而PM_(2.5)浓度高的城市具有大规模集聚的特征,城市群即是PM_(2.5)浓度高的城市聚集区,受自然因素、社会经济因素和城市形态因素共同作用。在2000–2005年,中国城市PM_(2.5)年平均浓度从31.19μg m^(–3)增加到46.00μg m^(–3),河北、山东、河南交汇地区出现小规模高浓度集聚。在2005–2010年、2010–2015年两个阶段,城市PM_(2.5)浓度年平均增长率放缓,2010年为47.67μg m^(–3),2015年为48.72μg m^(–3)。高浓度集聚区域不断扩大,在2010年扩张至京津冀、长江中部、长江三角洲、成都平原,研究期末已经扩大至整个华北平原、哈长地区。

Based on the scientific identification of urban built-up areas,the spatial and temporal characteristics of PM_(2.5) concentrations in Chinese cities during 2000–2015,and the factors influencing them,were analyzed by exploratory spatial analysis and spatial econometric models.The results showed that the concentration of PM_(2.5) in Chinese cities increased in an inverted“L”pattern during 2000–2015.However,the cities with high PM_(2.5) concentrations are characterized by large-scale agglomeration,and urban agglomeration is an urban agglomeration area with a high PM_(2.5)concentration.Specifically,the areas with high PM_(2.5) concentrations are affected by natural factors,social and economic factors and urban form factors which all work together.From 2000 to 2005,the annual average concentration of PM_(2.5) across all Chinese cities increased from 31.19μg m^(–3) to 46.00μg m^(–3),and small-scale high concentrations were densely concentrated at the intersection of Hebei,Shandong and Henan.From 2005 to 2010 and from 2010 to 2015,the annual average growth rate of the PM_(2.5) concentration in urban areas slowed down,with average levels of 47.67μg m^(–3) in 2010 and 48.72μg m^(–3) in 2015,representing increases of only 3.63%and 2.20%,respectively.In 2010,the high-concentration agglomeration areas expanded to include the Beijing-Tianjin-Hebei region,the Central Yangtze River,the Yangtze River Delta,and the Chengdu Plain;while in 2015 they further expanded to the entire North China Plain,the Central Yangtze River,and the Harbin-Changchun region.