Evolution analysis of the coordinated network between urbanization and multifunctional land use in the Han River Basin of China

Multifunctional land use and urbanization can be coordinated to realize regional high-quality development. In this study, the evaluation system was constructed for the urbanization and land use multifunctionality using the county data of the Han River Basin from 2000 to 2020. A multifunctional network was also established using the coupling coordination degree model, improved gravity model, and social network analysis. The results show that: (1) There was a generally low degree of coupling coordination in the land use multifunction and urbanization, indicating a consistent upward trend over the years. Most areas were approaching an imbalanced state by 2020, while some regions in the middle and lower reaches demonstrated moderate coordination. The spatial distribution pattern revealed that the western areas shared the lower coordination, compared with the eastern. Similarly, the upper reaches exhibited lower coordination than the middle and lower reaches. The high-value regions were primarily concentrated in the municipal districts, indicating the generally coordinated and orderly development between regional urbanization and land use multifunction. (2) In terms of coordination network analysis, there was a gradual increase in the coordination network density during the study period. The network density was found to be higher in the middle reaches than in both upper and lower reaches; There was a progressive strengthening of coordination networks among cities. The spatial distribution was consistent with the network density, where the upstream exhibited less density, compared with the middle and downstream regions. Moreover, there was a great transition from a simple bus structure to a complex network for the coordinating networks, as the cities expanded their correlation direction outward along the main streamline. (3) The central nodes were primarily situated in the middle section of the upper reaches and the southern region of the lower reaches. The access nodes were distributed in the western area and lower reaches of the upper reaches, while the control nodes were scattered throughout all sections. These three centrality nodes shared overlapping areas. Notably, Jingshan County, Mian County, Hanbin District, and Liuba County exhibited high degrees of centrality, in terms of degree centrality, proximity centrality, and intermediary centrality. There was the radiating influence of central cities on the urban centers. These cities also served as the resource exchange among sites. (4) According to the multifunctional coupling coordination and network centrality of urbanization and land use, the cities were divided into four types, namely, comprehensive coordination, key development, hub, and potential type. Potential and hub cities were dominated in the basin. While the key development cities were clustered difficult to radiate the entire basin, indicating the fewer comprehensive coordinated cities. Therefore, it is necessary to formulate some measures under the local conditions, and then promote the high-quality development of the Han River Basin.