基于VIIRS夜间灯光的中国城市中心的分异特征及其影响因素

城市多中心是现代城市发展的重要趋势,精准识别城市中心和理解城市中心形成机制对推进以人为核心的新型城镇化具有十分重要的意义。基于VIIRS夜间灯光数据设计出城市中心识别方法,对全国286个地级以上城市的城市中心进行识别,从城市中心数和中心发展的均衡度两个方面对城市中心的分异特征及影响因素进行分析。结果表明：① 在全国286个城市中识别出181个多中心城市,所识别的城市中心与城市规划中心具有很大程度一致性,识别结果具有一定的可靠性。② 城市中心数表现为“东多西少”的空间格局,并随城市规模等级的增加呈现“S”型递增趋势。③ 城市中心发展的均衡度呈现“东高西低”的空间格局,并随城市规模等级的增加呈现稳定递增,到特大型城市基本保持稳定。④ 河流对市区的分割、市区是否临海以及市区平地占比等自然地理因素对城市中心发展具有影响,但是社会经济因素影响更大;社会经济因素中,轨道交通站点数、市辖区人口数、城市规模等级、地区生产总值、第三产业占地区生产总值比例、固定资产投资对城市中心发展具有显著影响。

The spatial differentiation and influencing factors of urban centers in China based on VIIRS night light

A polycentric city is an important trend in the development of modern cities. Identifying accurate urban centers and understanding formation mechanism of urban center are of great significance to promoting the new urbanization with the people-oriented idea. Based on the VIIRS night lighting data, the paper designs the identification method of the urban center, identifies the urban center of 286 prefecture-level cities, and analyzes the differentiation characteristics and influencing factors of the urban center from the number and the centrality index. The results show that: (1) The 181 polycentric cities have been identified in 286 cities throughout the country, the identified urban center is in great agreement with the urban planning center, and the results have a certain reliability. (2) The urban center number presents the spatial pattern of more in the east and less in the west, and presents the "S" type increasing trend with the increase of the city scale. (3) The equilibrium index shows the spatial pattern of high in the east and low in the west, suggesting a steady increase with the increase of the scale of the city and remain stable until a megalopolis forms. (4) Natural geographical factors such as the segmentation of the rivers, the adjacency of the sea and the proportion of the flat land have influence on the development of the city center, but the social and economic factors has more impact on this process. Social and economic factors, the number of rail transit station, city population, city scale, GRP, proportion of third industries and investment in fixed assets have a significant impact on the polycentric development.