公路网对外交通可达性评价——以广东省为例

Accessibility evaluation of road network to external traffic——a case study of Guangdong Province

为了研究公路网对外交通的可达性,提出了一种基于多指标、多目的地点的可达性综合评价方法。首先运用ArcGIS软件,以最短出行时间和最短出行距离为评价指标,设定广东省各地级市政府为起始点,省内港口、高铁站、机场为目的地点,通过采用综合集成赋权方法,建立兼顾系统"功能性"与"均衡性"的评价模型,得到各城市到达3种目的地点的可达性评价值。然后根据评价值进行层次聚类,把所有地级市分为可达性较好、可达性一般、可达性较差3个等级。最后根据已有的等级进行判别分析,得到进行综合评价时3种目的地点所占的权重系数。研究结果表明,城市节点的几何居中性越好,其可达性的评价值越高;3种对外交通方式中,省内区域至高铁站的可达性对评价对外交通水平影响较大;根据可达性水平把地级市分为3个等级,并建立不同等级的线性判别模型,可依据此模型判别广东省内任一区域的对外交通可达性水平。此综合评价方法适用于各地区可达性研究,具有一定的普适性。

In order to study the accessibility of road network to external traffic,a comprehensive reachability evaluation method based on multi-index and multi-destination is proposed.First,this paper uses ArcGIS software,the shortest travel time and the shortest travel distance are taken as the evaluation indexes,the prefecture-level cities of Guangdong Province are chosen as the starting points,the ports,high-speed rail stations,airports of Guangdong Province are selected as the destination points,through the use of comprehensive integration method to establish both ＂functional＂ and ＂ balanced＂ evaluation model,the reachability evaluation values of the three destination points are obtained.Then according to the evaluation value of hierarchical clustering,all prefecture-level cities can be divided into better accessibility,average accessibility,poor accessibility.At the same time,according tothe existing level,the weight coefficient of the three target sites is obtained.The results show that the better the geometric neutrality of urban nodes,the higher the evaluation value of its reachability.Among the three kinds of modes of external traffic,the accessibility of the provincial region to high-speed rail stations has a great influence on the evaluation of the level of external traffic.According to the accessibility level,the prefecture-level cities are divided into three grades and different levels of linear discriminant models are established,which can be used to discriminate the level of external traffic accessibility in any region of Guangdong Province.This comprehensive evaluation method is applicable to the study of accessibility in various regions.