Multi-scale Analysis about Urban-Rural Road Network of Four Major Metropolitan Area in China Based on Fractal Theory
基于武汉、珠三角、长三角和京津冀四大都市区的城乡路网空间数据，建立三种分形模型，分析路网分布密度、覆盖度及节点关联性的分形特征与演化规律。
Based on spatial data on urban and rural road network(URRN) of Wuhan Metropolitan Area(WMA),Pearl Delta Metropolitan Area(PDMA),Yangtze Delta Metropolitan Area(YDMA) and Beijing-Tianjin-Hebei Metropolitan Area(BTHMA),this paper establishes three fractal model including length-radius dimension,box-counting dimension and correlation dimension,so as to explore the fractal features of URRN and its evolution rules of the four Metropolitan Area(MA):(1)distribution density of URRN generally forms a gradient attenuation trend(from center to peripheral),and there have some structural differences of fractal development level among the four MA.For example,when changes the measure center,it does little effect on the dual-core MA fractal dimension(BTHMA and PDMA),whereas multi-core MA(YDMA) shows an abnormal performance under the influence of measuring center changing and urban-rural system;(2) the covering dimension values of different MA correspond to the Longitude zonal Law,meaning the URRN in WMA has a great potential to be improved.Obviously,the coverage of URRN is effected by its population size,economy level,exchange intensity and so on.There exists positive correlation and space conjugate relation between the coverage level of URRN and MA socio-economic development level;(3) with a kind of relatively uniform spatial distribution,the association between urban nodes and rural nodes is incompact.Moreover,Spatial scale and cities organization system have Significant impact on nodes correlation dimension of URRN.