基于LMDI的城市化不同阶段PM_(2.5)浓度影响因素——以我国5个特大城市群为例

Socio-economic factors of PM_(2.5) concentrations in different urbanization stages based on LMDI:A case study of China’s five mega-large urban agglomerations

以我国5个特大城市群为研究区,采用人均GDP和产业结构标准,将2000~2015年划分为不同的城市化发展阶段,利用LMDI指数分解法探讨不同发展阶段排放强度、能源强度、经济产出和人口规模等4种社会经济因素对PM_(2.5)浓度变化的可能驱动机制及贡献率.结果表明,5个特大城市群被划分为四个不同的城市化发展阶段,随着城市化进程的推进,PM_(2.5)浓度呈现先上升后下降的趋势.总体上,经济产出和人口规模产生正效应,且经济产出效应是促进PM_(2.5)浓度增加的主要因素;排放强度和能源强度产生负效应,且排放强度效应是抑制PM_(2.5)浓度增加的主要因素.能源强度效应的累积贡献率在工业化初期和中期有正有负,但在工业化后期和发达经济时期均为负.从工业化初期至发达经济时期,经济产出效应和人口规模效应的累积贡献率均在增加且经济产出效应的累积贡献率增加更为显著;排放强度效应的累积贡献率为负且累积贡献率的绝对值不断增加.探讨不同城市化发展阶段PM_(2.5)浓度的影响因素可为政府部门制定针对性的环境保护政策提供依据.

Taking five megalopolises in China as cases,this paper divided the period from 2000 to 2015 into four different urbanization stages with the indexes of GDP per capita and industrial structure.Then,the driving mechanism and contributions of emission intensity,energy intensity,economic output and population scale on PM_(2.5) concentrations were explored for different urbanization stages,using the Logarithmic Mean Divisia Index model(LMDI).The results showed that PM_(2.5) concentrations of these megalopolises increased in early stages and then decreased in the later.Generally,economic output and population scale had positive effects on PM_(2.5) concentrations.Especially,the former played a dominant role in promoting PM_(2.5) concentrations.Meanwhile,emission intensity and energy intensity had negative effects on PM_(2.5) concentrations,and the former was the main factor restraining the increase of PM_(2.5) concentrations.The cumulative contributions of energy intensity appeared vague during the primary and middle industrialized stage,while showed negative in the late industrialized and developed stage.The cumulative contributions of economic output and population scale were both positive during the whole stages,while the contributions of economic output had significantly increased.The cumulative contribution of emission intensity was negative,and its absolute value increased continuously.These results could provide a basis for understanding the driving mechanism and contribution of different factors on PM_(2.5) concentration of megalopolis,and thus could support government in making related environmental protection policies.