中国不同交通模式的可达性空间格局研究

交通运输网络是经济发展的重要保障,分析可达性空间格局差异对引导人口分布和交通设施合理建设具有重要意义。以中国2 317个县级行政区域为研究对象,采用加权平均旅行时间法,通过构建可达性指标分析了公路、铁路、机场、港口及综合交通的空间格局。结果表明:公路可达性形成了以郑州、武汉、合肥为中心的"核心-外围"模式;铁路形成了以京沪线为轴线,沿铁路干线分布的带状结构,最优区已南移至合肥及南京;机场可达性形成了以各个枢纽机场为核心的"轴-辐"结构;港口可达性由沿海向内陆降低;综合交通可达性由东向西降低,具有反自然梯度特征。4种交通方式的可达性总体水平较高,约有70%的县域超过平均水平,与人口分布具有一定的相似性,东部城市高于西部城市,但存在区域内的不均衡现象。最后对各交通方式出现的问题提出了一些针对性建议。

STUDY OF THE SPATIAL PATTERN OF ACCESSIBILITY FOR DIFFERENT TRANSPORTATION MODES IN CHINA

Transportation network is the basis of economic development.Analysis of the differences in the spatial pattern of accessibility is of great significance for population distribution and construction of transportation facilities.By using weighted average travel time as an indicator of accessibility,in this research we first calculated the accessibility of highway,railway,waterway,civil aviation,and integrated transportation in China with 2 317 counties as the basic analysis units.Second,we analyzed the geographic patterns of accessibility,which showed that (1) highways formed a "core-periphery" pattern with Zhengzhou,Wuhan,and Hefei at the cores;(2) the geographic pattern of railway accessibility showed a belt pattern that resembled the expansion of the transport network;the center of accessibility moved toward to Hefei and Nanjing;(3) the accessibility of civil aviation gradually decreased from hub airports to the trunk and feeder airports and displays a hub-and-spoke pattern;(4) the accessibility of waterways declined gradually from the coast to the inland;and (5) the integrated transportation accessibility had a reverse-to-natural gradient.The overall level of accessibility of four transportation modes was high with 70％ above the average value of accessibility.For most of counties,transportation accessibility presented a distribution of"high in the east and low in the west" and was related with population distribution in China.Inequality of accessibility still existed in the internal region.Finally,some suggestions were put forward to deal with these problems.