中国三大经济圈城市体系空间结构的分形研究

A Fractal Study on the Spatial Structure of Urban System in the Three Economic Circles of China

利用分形理论中的聚集分维、分形结构因子和均衡度计算长江三角洲、珠江三角洲和环渤海经济圈城市体系空间结构维数,并分析其分形结构特征.结果表明:长江三角洲由于生态系统边缘效应和交通通信网络的发达而表现出内部空间结构的紧致性;随着珠江三角洲社会经济发展和市场发育,其城市空间亦趋于集聚和整合;环渤海经济圈则由于社会经济活动集中于渤海湾地区而形成了差异较大的内外圈层,城市体系空间结构最为松散.最后基于分形理论的测算与分析结果,提出了3个经济圈城市体系空间结构和功能优化的建议.

From the perspective of fractal study, the spatial structures and fractal characters of urban system in the Yangtze River Delta, the Bohai Economic Circle and the Pearl River Delta are measured and analyzed, using parameters including aggregation fractals, fractal structure factor and equilibrium degree. For the Yangtze River Delta, owing to the particular edge effects of ecosystems and modern development traffic and communication networks, the internal structure of the urban system there achieves high level of compactness. In the Pearl River Delta, it is predictable that, with further development of economy and markets, centrality and conformity of urban system in the Pearl River Delta would continue to increase. As for the Bohai Economic Circle, the highly centralized distribution of socio-economic activities along the Bohai Bay leads to the formation of two distinctive circles and the level of compactness of urban system is lowest among three study areas. Based on related measurement and analysis, we put forward some advices for the optimization of spatial structures and functions of urban system for the three economic regions.