南京城市交通方式可达性空间分布及差异分析

将南京都市区划分为5个圈层和566个交通小区,采用南京都市区2006年土地使用现状数据,用区位熵采衡量社会经济发展机会数,根据机会累积可达性测度方法,计算了20、40和60min三种阀值下的自行车、小汽车和公共汽车的空间可达性.结果显示:①在当前建成环境下,交通方式的空间可达性呈同心圆模式;②小汽车相对于公共交通和自行车的可达性优势非常明显;③尽管公共交通在长距离或长时间出行中,相比自行车有一定优势,但是在近距离或短时间出行中,可达性优势很微弱;④在正处于快速城市化地区的中心城圈层和外围圈层,公共交通的可迭性小于自行车,说明当前的公共交通设施供给与土地开发模式不利于公共交通方式的发展.

A Spatial Analysis of the Modal Accessibility Gap in Nanjing Metropolitan Area

The Nanjing metropolitan Area is divided into 5 zones and 566 TAZs in this paper. Using the original land-use data in 2006, the Location Entropy Indi-cator (LEI) of residential, industry and commercial land are calculated as the proxy of opportunities. The modal accessibility of bicycle, car and urban transit are mea-sured based on the method of cumulative-opportunity under three assumptions of isochrones time: 20, 40 and 60 minutes. The result shows that: ①under the exist-ing built environment, the spatial structure of the modal accessibility displays a con-centric zonal pattern; ②the strength of car accessibility relative to bicycle and urban transit is apparent; ③comparing the modal accessibility of urban transit and bicycle, the strength of urban transit accessibility is relatively high when the isochrone time is assumed to be 40 or 60 minutes, but the strength is weak when the isochrone time is assumed to be 20 minutes; ④In the central city zone and periphery zone where rapid urbanization is observed, the accessibility of urban transit is lower than the bicycle. It is suggested that the existing public transportation infrastructure and the mode of land development is not conducive to the development of urban tran-sit.