基于最短路径模型,以经济权重可达性和经济潜力指数为主要指标,对近20年湖南公路网络演化和空间格局进行分析。结果表明:1984-2004年,湖南公路网络通达性呈现以长株潭为核心的同心圈层结构,呈现“中心-外围”向外递减,到2004年等值线密度趋于平缓,显示以长株潭为强极,外围湘北(岳阳)、湘南(郴州)为次极和湘西(怀化和吉首)为弱极的空间结构;20年来,湖南省内部可达性绝对差距逐步缩小,相对差距逐步加大,经济发展潜力以长株潭为核心沿主要交通轴线呈指状递减。可达性和经济结构相关分析表明,湖南空间结构由1980年代的低级无序状态变为2004年的多核不均衡集聚扩散状态,未来需要大力优化湘西地区可达性和加快经济的发展,促进空间格局向均衡有序的方向发展。
Based on the "shortest path matrix", with the indexes "weighted mean travel costs" and "economic potential", the author studied the optimization of highway network in Hunan province and the evolution of spatial pattern from 1984 to 2004. With the economic accessibility and the index of "economic potential" it is possible to analyze the spatial pattern effectively through the changes of transportation network; it is beneficial to organize the urban and regional spatial structure, which will support the region's exploitation and the transportation's organization. The study result is that from 1984 to 2004, the accessibility of the highway network in Hunan province was a "core to edge" spatial configuration. The accessibilities isolines have been relaxed. The "CHANG-ZHU-TAN" region is a stronger core and the Yueyang county, Huaihua and Jishou are weak in the spatial configuration. From 1984 to 2004, the disparity of the absolute accessibility was reduced, and that of the relative accessibility became increasingly. The changes of economic potential reducing followed the transportation lines, and took as a "hand-shape". According to the "weighted mean travel costs" and "economic potential", the author divided the Hunan province into four categories of counties., the best development region, the better development region, the popularly development region and the worse development region. The accessibility shows the spatial configuration with a "point-axis" sign in 2004, which is contrary to the "lower-level and out-of-order" in 1984. In the future, the government should develop the "CHANG-ZHU-TAN" region and "one point and one line" regions, which will promote the fast Hunan provincic economic level greatly and form the economic channels in the eastern part of Hunan province. At the same time, the government should make great efforts to improve the accessibility in the western part of Hunan province, narrow the big gap of the economic development level in the