改进权重的京津冀可达性时空变化对比分析

以2000年和2015年两个时间断面京津冀地区最省时的交通网络为基础数据，利用ArcGIS网络分析模块，分析节点城市可达性的时空变化规律。在研究方法上突出强调某一时间断面最省时的交通网络体系和通过节点中心度改进的加权平均旅行时间。结果显示：京津冀区域的可达性格局变化较大，可达性整体提升的同时，处于第一阶梯的区域大幅扩张；总体而言，区域内可达性从优到差排序依次为：中心城市、东部和南部城市、北部城市；交通方式的变革极大地改善了区域可达性，各城市的加权平均旅行时间普遍缩减50%以上，中部和南部城市的变化率要远远大于北部城市；张家口和承德两市受山地地形和交通基础设施的限制，可达性一直处于较低水平。

Comparative analysis on the spatio-temporal changes of accessibility between Beijing-Tianjin-Hebei area based on improved weight

Beijing, Tianjin and cities of Hebei Province form an important urban agglomeration in Northern China. Integrating transportation networks is an efficient way to boost the development of this area. Based on the data of the most convenient traffic network of Beijing-Tianjin-Hebei in 2000 and 2015, using ArcGIS network analysis, the change of accessibility of nodes was detected. In the research method, we highlighted the most time-saving section of a traffic network system and weighted average travel time improved by degree centrality. The findings are as follows. The accessibility pattern of Beijing-Tianjin-Hebei area has changed greatly, with the overall accessibility upgraded, and the one hour transportation area expanded. The accessibility within the region decreases in the following order: central cities, eastern and southern cities, northern cities. Shift of transportation modes has greatly improved regional accessibility, with a weighted average travel time between cities generally reduced by more than 50 percent. And the rate of change in the central and southern cities in the region is much greater than that in northern cities. Accessibility of Zhangjiakou and Chengde were the lowest in the region, hindered by the mountain topography and transport infrastructure constraints.