湖南公路网络演变的可达性评价

THE APPRAISE OF ACCESSIBILITY ON THE EVOLUTION OF HIGHWAY NETWORK IN HUNAN PROVINCE

利用可达性评价模型,计算1984—2004年公路网络演变过程中带来的可达性变化,并对2025年湖南高速公路网络可达性进行模拟。结果表明:湖南公路网络变化过程中,可达性显示以中南部为主的“中心—边缘”同心圈层结构,呈现明显“东北—西南”轴线特征,网络变化使湘西、湘南等边远地区受益巨大,但滞后的特征仍然显著。公路网络演变过程中,城市之间的可达性变异先减小后增大,到2025年,湖南高速公路网络完成,城市间可达性将逐步实现优化均衡,14个地级市4h通勤圈基本形成,长沙等核心城市2h交流圈的扩展将推动区域一体化的纵深发展。

Based or, the ＂shortest path matrix＂, the author calculated the accessibility of the highway network in Hunan province in 1984, 1993,：2004 and 2025. The paper gets the result： the cities in the highway network turn out the obvious ＂core- periphery＂ model with velocity index. The best accessibility is in the Mid - south of Hunan province and the accessibility＇ s circle is homocentric. The direction of the accessibility＇ change is distinct from northeast to southwest. In the process of highway network evolvement, the accessibility＇ improvement follow the law of diminishing returns of scale. The cities in the northwest and south of Hunan province are the worse. In the beginning of the highway improvement, the associated coefficients of variation （CV） have been larger. In the end of the Hunan freeway network construction, the accessibility will be in balance. In 2025, the most cities can be reached within four hours in terms of the 14 cities at prefecture level, with more cities can reach the circle of the two hours＇ intercommunion of the core region, the regional integration progress will be quicken.