基于POI大数据的重庆主城区多中心识别

我国大量城市在其规划中均提出多中心的空间发展战略,但多中心结构演变是否达到规划预期,能否通过有效途径识别多中心结构和功能,成为目前学术界研究的热点。相比于人口、用地、产业等传统调查和识别方法,城市大数据的出现为多中心识别提供了契机,尤其是基于POI（Point of Interest）大数据的分析比传统方法更加准确高效。论文以重庆主城区40余万条POI数据为基础,利用核密度分析、自然断点法和邻近分析等方法,根据整体及不同类型POI数据的空间分布特征与聚集程度,识别城市总体及不同职能的多中心结构及其影响范围。结果表明：重庆作为山地城市,在自然约束和规划引导下,呈现出明显的“多中心、组团式”结构。不同职能类型的城市中心也呈现明显的多中心分布特征。重庆的主副中心在内环以内集聚,但不同中心的发育程度及其空间聚集度差异显著。外围新兴的西永、茶园等副中心发展相对滞后,城市要素集聚功能有待加强。

Identification of Polycentric Urban Structure of Central Chongqing Using Points of Interest Big Data

Many Chinese cities have proposed the strategy of polycentric urban development in their master plans. There are still questions about polycentric urban development to be answered: does the evolution of polycentric urban form conform with the master plans? How to identify and measure the morphological and functional urban forms? Previous research has used traditional data to identify the polycentric form, such as population, land use and industry. Nowadays, the emergence of urban big data provides an opportunity to improve the accuracy of identifying urban form and structure. The new methods based on urban big data such as POIs (Points of Interest) can provide accurate and efficient estimation of polycentric urban structure compared with traditional methods. Using 408 768 POIs data in Chongqing urban area, this paper identified the overall pattern of polycentric structure and the polycentric structures of different functions by considering the spatial distribution and the degree of aggregation of POIs. This paper found that Chongqing as a mountain city, constrained by natural condition and stimulated by urban planning, has formed a typical “polycentric form composed of multiple subcenters and clusters”. The distribution of POIs shows that the subcenters have relatively comprehensive urban functions, such as financing, shopping, dwelling and recreation. The main center and several sub-centers in Chongqing gather within the inner ring road. The sub-centers have significant differences in terms of urban development and spatial aggregation. The peripheral subcenters such as Xiyong and Chayuan have lagged behind other subcenters. Therefore, urban aggregation need to be strengthened in the near future.