高铁联网背景下城市可达性空间格局演变

以"八纵八横"高铁网络为例,借助ArcGIS栅格分析法构建全国31个中心城市日可达性、加权平均旅行时间与可达性系数等指标,对比分析了中国现状及规划高铁对城市等时圈及可达性的影响。结果表明:等时圈在空间上以"中心一外围"模式沿着高铁线路延伸,预计"八纵八横"高铁网络全部建成以后,相邻中心城市(除乌鲁木齐、拉萨外)3小时圈连接形成紧密的网状;规划高铁对沿线城市等时圈及可达性的影响显著且差异明显,其对西部地区的影响最大,中部次之,东部最小;加权平均旅行时间在空间上呈现显著的等级差异化和空间集聚化特征,其最优区域将向西部拓展;除乌鲁木齐、拉萨外,其余城市可达性水平在空间上趋向均衡化。

Urban Accessibility and its Spatial Pattern Evolution under the Background of High-Speed Railway Network

Taking the"eight vertical and eight horizontal"high-speed rail network as an example,the article calculated the indicators of 31 central cities such as daily accessibility,weighted average time,and accessibility coefficient by raster analysis on ArcGIS,comparing the impact of high-speed rail on cities’daily communication areas and accessibility in the situation of status quo and planning.Results are shown as follow:the daily communication areas is extended along the high-speed railway line with the"centerperiphery"mode.Except Urumqi and Lhasa,all cities will be connected to form a three-hour tight mesh in 2025.The influences of planning high-speed rail on daily communication areas and accessibility of the cities along the route are significant and different.The impact on the western region is the largest,followed by the middle,and the smallest in the east.The weighted average time has significant spatial differentiation and spatial agglomeration characteristics,and its optimal area will be gradually expanded to the western region.Except Urumqi and Lhasa,the accessibility level of central cities tends to be equalized in space.