Identification and structural characteristics of urban agglomerations in China based on Baidu migration data

Abstract

Scope identification and structural characteristics are the basis of studies on urban agglomeration. The scope planned by central and local governments, as well as the existing structural models, mainly focuses on social-economic statistics, which rarely considers the links between cities. Population mobility network is a crucial driving factor of the human-land system evolution. Herein, we proposed a new analysis framework, including the new scope identification algorithm and the new structure representation model based on urban network. Results show that population flow network showed a diamond, and is consistent with the “Heihe-Tengchong Line”, which was similar to the population distribution; We found 20 urban agglomerations in China, which was much smaller than that planned, and the adjacent distribution was obvious; China's urban network consisted of four subnets, with Yangtze River Delta, Hebei-Beijing-Tianjin, Pearl River Delta and Chengdu-Chongqing as the center, respectively; Urban agglomerations were divided into single-core, dual-core and multi-core types, mainly in single-core structure; The internal intensities of the four top urban agglomerations were the highest, and the imbalance between inflow and outflow intensities caused either accumulation or loss of population. We further proposed some policy suggestions for sustainable development.