长三角地区城市化空间关联特征及内在机制

Urban spatial correlation characteristics and intrinsic mechanism in the Yangtze River Delta region

中国正处于城市化快速发展阶段,但当前研究在综合反映城市化的时空特征时,往往忽略区域城市间的空间关联及其演化过程,无法有效地揭示区域城市间的相互影响和内在机制。基于空间极化及扩散理论和系统分析方法,剖析了长三角地区城市化的空间演化过程。结果显示:①1995-2015年间长三角地区城市化的规模等级特征明显,作为区域增长极,上海处于第一等级,南京、杭州、苏州为第二等级;城市化空间关联指数也表明,以上海、苏州、杭州等10个城市构成区域最为密集的空间联系网络。②研究时段内,城市化过程中空间极化和空间扩散同时存在,且空间极化的城市往往会进入新的扩散阶段,以南京、杭州等城市表现最为明显。该结果证实了各城市间在不同发展阶段具有不同的空间作用关系。本文还探讨了区域城市化的驱动机制,表明区域内产业升级和转移是形成空间极化或扩散作用的主要内生动力。本研究可为区域发展规划提供重要的科学支撑。

China is experiencing rapid urbanization. It is of great significance to clarify the characteristics of urban spatial expansion and its evolution law for regional coordinated development. Urbanization involves many aspects such as economy and population. However,current researches still face challenges in comprehensively reflecting the spatial pattern,evolution process, and intrinsic mechanism of regional urbanization, and they cannot effectively reveal and quantify the spatial correlation and evolution process of regional urbanization. Based on the data of economy, population and urban space in the Yangtze River Delta region from 1995 to 2015, this paper used spatial polarization and diffusion theory to quantitatively analyze the spatial evolution process and characteristics of urbanization. The results showed that:(1) The characteristics of urbanization level in the study area were obvious.Shanghai was at the first level, Nanjing, Hangzhou and Suzhou were at the second level, and the rest of the cities were at the third, fourth and fifth levels. The spatial correlation intensity of urbanization shows that the high-value level was concentrated in the eastern part of the region and 10 cities, such as Shanghai, Suzhou and Hangzhou, constituted the most intensive urbanization development spatial network.(2) During the study period, the spatial polarization and spatial diffusion characteristics existed simultaneously in the Yangtze River Delta region.During the study period, a diffused region always rapidly presented a patttern of polarization in space, then the polarization weakened and turned into a new diffusion phase. It is most obvious in Nanjing and Hangzhou among all the 41 cities. Our findings completely demonstrate that the spatial correlation among cities is changing over time. This study also explored the driving mechanism of regional urbanization, indicating that industrial upgrading and transfer within the study area is the main endogenous driving force for spatial polarization or diffusion. Our study has important theoretical and practical value for future regional development planning.