基于GIS网络分析的城市公交车路网可达性

Accessibility of urban bus networks based on GIS network analysis

针对城市地表空间异质性和交通可达性测度问题,提出一种基于地理信息系统(Geographical Information System,GIS)的网络分析和距离成本加权算法,研究城市公交车路网的空间距离和时间可达性.利用网络拓扑模型构建汉中市道路节点-链路网络;采用两步移动搜寻法(Two-step Floating Catchment Area method,TFCA),考虑社区单元人口、公共设施、土地利用和城市规划等约束成本,分析城市公交车网络覆盖区域的距离可达性、时间可达性和综合可达性.结果表明:汉中市公交车网络的时间和距离可达性值,由中心城区向主城区、近郊区和远郊区的依次减弱.中心城区和主城区的公交车网络的可达时间小于20 min,可达距离小于5 km;市远郊区和偏远乡镇的公交车可达时间大于50 min,可达距离大于10 km.未考虑公交路线之间的闭合和站点优化问题,市远郊区的公交车覆盖区域的时间和距离可达性较差.

In order to measure the spatial heterogeneity of land surface and accessibility of urban transportation,an algorithm based on Geographical Information System(GIS)network analysis and distance cost weighting method is proposed to analyze the spatial distance and time accessibility of urban bus networks.The node-link road network in Hanzhong is constructed by the network topology model.The distance,time and comprehensive accessibility of urban bus traffic network are analyzed by Two-step Floating Catchment Area method(TFCA),considering the committed costs of the community population unit,public facilities,land utilization and urban planning.The results show that both time and distance accessibility of urban bus network in Hanzhong gradually weakens from the central city to the main urban area,suburban area and outer suburban area.In the central city and the main urban area,the maximum reaching time within the bus network is less than 20 minutes,while the reachable distance is less than 5 kilometers.In the outer suburbs and far towns,the maximum reaching time within the bus network is more than 50 minutes,and the reachable distance is more than 10 kilometers.Without considering the closure of bus routes and the optimization of bus stations,the time and distance accessibility of areas with bus service is poor in the outer suburbs of Hanzhong.