基于跨城出行联系的城市群等级结构测度与规划建议——以长江三角洲城市群核心区为例

Measurement and the Planning Proposal of the Hierarchical Structure of Urban Agglomeration Based on Inter-city Trip Linkages:A Case Study on Core Regions of Urban Agglomeration in the Yangtze River Delta

基于跨城出行联系测算了长江三角洲城市群核心区域城市体系的等级结构.首先使用手机信令数据识别出长三角城市群核心区域内居民跨城出行联系.不同时段跨城出行联系表达了城市群内部不同类型的功能联系.随后,综合运用5种方法测算了跨城出行联系表达的城市等级.与基于人口规模等级结构相比,基于功能联系的城市群等级结构更具有扁平化特征,基于功能联系的长三角城市群城市等级结构也具有时间维度特征.上海依然是核心城市,杭州市区的等级显著提升,昆山市等城市在跨城功能联系网络中的地位也较高.对照已有城市群相关规划,功能联系维度下高等级的城市主要是部分传统中心城市和部分苏南地区的经济发达的中小城市,一些传统地区中心城市的等级降低.城市等级结构具有空间不平衡特征.

The hierarchical structure of the urban system in the core area of the Yangtze River Delta urban agglomeration is measured using inter-city trips.First,the inter-city trips in the study area are identified using mobile signaling data.These inter-city trip linkages in different periods represent different functional-linkage types within the urban agglomeration.Next,urban hierarchical structure expressed by inter-city trip linkages are estimated using a combination of five methods.The results reveal that,compared with the measurement of the hierarchical structure based on population scale,the hierarchical structure based on functional linkages give more even result.Additionally,the hierarchical structure of the urban agglomeration based on functional linkages in the Yangtze River Delta region included the dimension of time.Shanghai is still a core city,but the level of Hangzhou has increased significantly and cities such as Kunshan occupy a significant status within the inter-city trip network.Compared with the existing plans for urban agglomeration in the Yangtze River Delta,the current study reveals that,in terms of functional linkages,high-level cities are predominantly occupied by traditional central cities and by the economically-developed small-and medium-sized cities in southern Jiangsu.Furthermore,it is found the levels of some traditional regional cities have been reduced.More specifically,the hierarchical structure of the urban agglomeration demonstrates characteristics of spatial imbalance.