高铁背景下城市铁路可达性与空间相互作用格局——以江西省为例

基于改进的可达性测度和引力模型，选取江西省11个设区市作为研究对象，在2010年、2013年和2016年3个时间断面下，测度了江西省城市铁路可达性和空间相互作用强度，并借助GIS工具进行时空格局演变分析。研究发现：(1)从高铁“洼地”到高铁“高地”的江西省，城市可达性呈现以省会南昌为核心、赣北铁路枢纽城市为次中心，向周边蔓延的“中心-外围”模式；城间作用度呈现以主干铁路通道为轴、枢纽城市为节点的“点-轴”模式，向周边辐散并呈现南北梯度差异;(2)高铁开通和区域一体化是提升城市可达性的重要驱动器和加速器，其巨大的时空压缩效应不仅弱化了空间距离对城间作用度的影响，而且促进了其质的飞跃；城市可达性和城间作用度呈现出明显的地带性和“通道效应”，城间列车开行密度是其重要影响因素;(3)高铁的影响范围有限，赣北高铁网络效应强于赣中南，通道内城市可达性趋于均衡，但也拉大了与通道外偏远城市的差距，尚未深度融入省内高铁网络的城市面临被边缘化的风险;(4)全省作用度格局呈现地域分化特征，形成中、北、南3个子系统，城间作用度差异呈现扩大趋势，处于追求“效率”阶段。基于此，江西应加速推进全省铁路和高铁网的建设完善，合理规划铁路站点规模，精准分配城间列车频次；城市应积极主动融入全省高铁网络，加强与周边城市一体化和本地接驳交通建设，提升综合交通可达性和空间作用度；全省应统筹南北梯度发展，稳步推进区域一体化，进一步打破地域隔绝与分化，推动城间均衡融合发展。

Urban Rail Accessibility and Interurban Spatial Effects on the Background of High-Speed rail in Jiangxi Province

By improving the method of measuring accessibility and adopting adjusted gravity model, this paper collected the data of 11 cities of Jiangxi Province in 2010, 2013 and 2016, then measured the urban rail accessibility (URA) and interurban spatial effect (ISE) among cities, and analyzed the evolution of space-time pattern based on GIS. Research findings: (1) From the High-speed rail (HSR) "depression" to the HSR "highland", the layout of URA in Jiangxi Province takes Nanchang as the core, rail hub cities as the sub centers, and spreads to the surrounding areas with the "center-periphery" pattern. The ISE takes the main rail channels as the axes, and take the rail hub cities as nodes with the "point-axis" pattern. Both of them show the gradient differences between the north and south with the radiation diffusion to the suburb of Jiangxi Province. (2) HSR and regional integration are two important drivers to improve the URA. The huge compression of time and space weaken the influence of space distance on ISE, and promote the leap of ISE. URA and ISE show significant zonality and "channel effect", which are greatly affected by the density of operating trains among cities. (3) The impact range of HSR is limited, and its network effect in northern part of Jiangxi is stronger than that in central and southern part. The URA in the channel tends to be balanced, but it also widen the gap with the remote cities outside the channel, and the cities which haven’t been deeply integrated into the HSR network of province are at risk of being marginalized. (4) The ISE in Jiangxi Province shows obvious regional differentiation characteristics, forming three sub-systems in the middle, north and south. The difference of ISE is expanding, so the ISE in the province are in the pursuit of "efficiency". Based on this, Jiangxi Province should accelerate the construction and improvement of the rail and HSR network, design the scale of the stations rationally and distribute the train frequency accurately. Each city should actively be integrated into the HSR network of the province, and strengthen the local connection traffic construction and the integration with the surrounding cities, to enhance urban comprehensive transport accessibility and ISE. Jiangxi Province should co-ordinate north and south with gradient development, steadily promote regional integration, further break the geographical isolation and differentiation, to promote the balanced development between cities.