Identification and characterization of urban polycentric structure based on points of interest in Shenyang, China

Analyzing the spatial agglomeration and characteristics of urban functional elements and effectively identifying the polycentric pattern of a city can provide a scientific basis for urban planning. This study, on the basis of point-of-interest (POI) data, designs a weighted overlay-analysis method that is based on functional categories, spatial agglomeration, and POI weights to identify the spatial-agglomeration pattern and polycentric urban structure of Shenyang, China. Our results show that Shenyang has a significant polycentric urban structure. The POI elements in the municipal center in the second ring road show concentration and a contiguous distribution pattern. The POI element distribution near the city is scattered, and the spatial distribution of hotspots is uneven. The urban centers in the city planned by the government and those that we have identified differ. Because of the remote location and insufficient support facilities, the municipal subcenters and district centers do not play the role of decentralization as intended. Further strengthening the overall industrial planning and transportation apparatus is necessary in order to enhance the outward radiation and inward attraction of municipal subcenters. Our weighted overlay method realizes effective identification of the polycentric urban structure and can provide relevant reference for urban research and planning.