汉江流域城镇化与土地利用多功能的协调网络演变分析

城镇化发展造成土地资源稀缺和用地不合理问题，而土地多功能利用是破解这一问题的关键。该研究基于汉江流域2000—2020年的县域数据，构建城镇化与土地利用多功能的评价体系，借助耦合协调度模型、改进的引力模型和社会网络分析法建立汉江流域城镇化-土地利用多功能的协调网络，分析协调网络演化特征，并结合各县域城镇化与土地利用多功能协调特点及网络特性进行协调分区。结果表明：1）汉江流域城镇化与土地利用多功能之间的耦合协调度总体水平较低，但呈逐年增长趋势，空间分布特征为西低东高，上游低于中下游。2）城镇化与土地利用多功能的协调网络密度逐年增加，网络格局由总线型结构演变为复杂的网状结构，网络的多中心趋势逐渐增强，说明不同县域城镇化与土地利用多功能耦合协调度之间的联系越发紧密。3）京山县、勉县、汉滨区和留坝县同时具有较高的度数中心度、接近中心度和中介中心度，表明这4个县域位于汉江流域城镇化与土地利用多功能协调网络的中心位置，对区域要素具有较强的控制作用。4）根据城镇化与土地利用多功能的耦合协调度及网络中心度指标对汉江流域进行协调分区，分为综合协调型、重点发展型、枢纽型和潜力型4类城市，并针对不同类型城市特点提出相应的政策建议。

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 2015. 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.