城市群客运网络节点重要度识别方法

A Method for Identifying Node Importance of Passenger Transport Network in Urban Agglomeration

为了识别城市群中城市节点重要度,考虑城市基础经济属性、城市公路与铁路客运拓扑网络属性以及城市联系强度属性3方面特性,提出了一种新的城市群综合节点重要度计算方法。首先通过传统节点重要度计算方法,考虑经济、交通以及信息活跃度3种特性,计算城市群中各城市基础经济属性;其次,基于城市群综合客运网络拓扑结构,引入复杂网络中聚集度以及介数中心性指标,分别计算公路与铁路综合城市拓扑网络属性;然后,由于城市群中各城市联系相关性较强,因此在考虑城市群各城市联接属性的基础上运用改进的重力模型构建城市联系强度模型,计算城市联系强度属性指标;随后通过全多边形综合图式法综合上述3方面属性得出城市综合节点重要度,并根据k-means聚类分析得到城市群中城市重要度分级,为城市群综合交通运输网络的构建与完善提供参考。最后,为验证方法的合理性与适用性,以四川城市群为例进行了实例计算。结果表明,四川城市群是以成都为核心的单核城市群,其次重要城市内江与南充可以作为四川城市群的辅助核心,分担成都城市经济与交通的发展压力。同时,四川城市群存在11个一般城市与5个不重要城市,说明四川城市群仍旧在发展阶段。

To identify the urban node importance in the urban agglomeration, considering the characteristics of urban basic economic attributes, topological attributes of road and railway transport networks, and urban linkage strength attributes, a new method for calculating comprehensive node importance of urban agglomeration is proposed. First, considering 3 features including economic, transport and information activity, the basic urban economic attribute indexes are calculated by traditional node importance calculation method. Second, based on the topology structure of comprehensive passenger transport network, the aggregation and betweenness centrality index in complex network theory are introduced to calculate the topological attributes of road and railway passenger transport networks. Third , because of the strong linkage among cities in the urban agglomeration, an urban linkage strength model is set up by using the improved gravity model to compute the linkage strength indexes based on the linkage attributes among cities in the metropolitan area. Afterwards, by using the entirearray-polygon ( EAP) method and integrating the 3 aforementioned attributes, the synthetic node importance degree is obtained to acquire the grades of cities in the urban agglomeration by k-means cluster analysis, which can be utilized for the construction and improvement of transport network in urban agglomeration. At last, a case study based on the Sichuan urban agglomeration in is performed to verify the rationality and applicability of the method. The result shows that (1) Sichuan metropolitan is a single-core ( Chengdu City) urban agglomeration, and the 2 submajor cities (Neijiang City and Nanchong City) can be seen as the auxiliary cores to share the economic and transport development pressure of Chengdu City. Besides, there are 11 normal cities and 5 insignificant cities in Sichuan urban agglomeration, indicating that the Sichuan megalopolis is still in the stage of development.