宁蒙沿黄地带最小综合交通时间成本的城市影响区

城镇体系规划已成为区域规划的主要内容之一,城市影响区划分具有现实意义。引力模型已成为城市影响区划分的主流方法,对引力模型进行2个方面的拓展:一是以城市建成区作为"源"实现城市"点"到"面"的拓展;二是综合交通数据和土地利用数据计算最小时间成本,并以此作为时间距离划分城市影响区。将城镇用地作为"面"状城市源,城市影响区轮廓与城镇用地轮廓具有相似性,反映出放大的城镇用地轮廓特征;最小时间成本原则下,城市影响区受道路类型尤其是通行时间成本较低的道路类型分布的影响显著,在两城市间格网通行时间成本相同前提下,两城市影响区分界线将垂直平分城市间通行时间成本最低的道路线;交通格局奠定了城市影响区基本形状,城镇用地作为城市"源"和土地类型格网通行时间成本的引入使得城市影响区轮廓不规则和精细化。

Urban Spheres of Influence Delineated by the Minimum Comprehensive Time Cost in the Areas along Yellow River in Ningxia and Inner Mongolia Autonomous Region

Urban agglomeration has been main form of China’ s regional development, and urban system plan-ning has been main part of regional planning.So it was meaningful to do research on urban spheres of influences in regional planning.Based on gravity model, two improvements were made in progress.Firstly, it conformed better to reality to take urban built-up area as source to which minimum time cost was searched for each cell.Secondly, by selecting the minor of travelling time cost through traffic and other land use grid, final minimum time cost was used to generate boundary between two different urban.Main conclusions were as follows:under rule of minimum time cost, urban spheres of influence was delineated distinctively by distribution pattern of different traffic lines, espe-cially the traffic line with minimum time cost.If region except traffic area between 2 urban had unique time cost, boundary of urban spheres of influence would be perpendicular to the traffic line with minimum time cost linking these 2 urban.Traffic line set basic pattern of urban spheres of influence while urban land area as urban “source”and difference of time cost on travelling through different land use grid just made boundary of urban spheres of influ-ence more irregular and delicate.