多维视角下的长三角城市群空间结构及其影响因素——基于NPP-VIIRS夜间灯光数据和高德人口迁徙数据

Spatial Structure and Influencing Factors of the Yangtze River Delta Urban Agglomeration from a Multidimensional Perspective:Based on NPP-VIIRS Nighttime Lighting Data and Gaode’s Population Migration Data

文章利用NPP-VIIRS夜间灯光数据、高德人口迁徙数据等,采用标准差椭圆、空间莫兰指数、网络中心性分析和核心—边缘分析等方法研究长三角城市群空间结构特征,并从经济水平、产业结构、公共服务和迁徙成本等方面研究长三角人口迁徙网络结构及其影响因素。研究发现:(1)长三角城市群发展不均衡,城市规模呈现东重西轻的局面,在空间上存在显著的空间正相关,具体表现为较大规模的城市相互邻近、较小规模城市相互邻近的核心—边缘空间结构,城市群沿长江和京沪高铁向宁合方向拓展。(2)根据人口迁徙强度,将长三角城市群人口迁徙网络划分为四级,随着网络层级下降,网络密度增加、节点城市增多。其中上海、苏州、无锡、南京和杭州等五市中心度较高,具有较强的辐射效应和集聚效应。(3)从人口迁徙网络来看,长三角城市群具有明显的核心—边缘结构,区域内部形成多中心、网络化协同发展格局。(4)工资水平、产业结构、交通便利性和医疗服务是影响长三角城市群人口迁徙的主要因素,均显著促进了人口迁徙。

This paper uses NPP-VIIRS nighttime lighting data and Gaode's population migration data to study the spatial structure characteristics of the Yangtze River Delta urban agglomeration using standard deviational ellipse method,spatial Moran index,network centrality analysis and core-edge analysis and to investigate the influencing factors of the Yangtze River Delta population migration network structure in terms of economic development level,industrial structure,public services and migration costs.It's found that:1)The development of the Yangtze River Delta urban agglomeration is uneven,which is higher agglomeration in the east than that in the west.There is a significant positive spatial correlation,specifically in the form of a core-edge spatial structure with larger cities close to larger cities and smaller cities close to smaller cities,the urban agglomeration expands along the Yangtze River,the Beijing-Shanghai high-speed railway and the direction of Nanjing-Hefei.2)According to the intensity of population migration,the Yangtze River Delta urban agglomeration is divided into four levels of population migration networks,with the network density increasing and the number of node cities increasing as the network level decreases.Among them,Shanghai,Suzhou,Wuxi,Nanjing,and Hangzhou have high degree of density and intense radiation and agglomeration effect.3)The Yangtze River Delta urban agglomeration has an apparent core-edge structure,with a polycentric,networked,and synergistic development pattern forming within the region.4)Wage level,industrial structure,transportation accessibility and medical services are the main influencing factors on the network structure of the population migration of the Yangtze River Delta urban agglomeration,all of which significantly promote population migration.