城市游憩场点系统结构分形及优化——以苏州市区为例

Research on the fractal structure and its optimization of city recreation site system:A case study of Suzhou city

以苏州市区为例,采用Zipf分维数、空间关联维数以及交通长度-半径维数三个指标,分别对城市游憩场点系统的等级结构、空间结构及交通网络通达性进行分维刻画。研究发现:首先,苏州游憩场点系统及其交通道路支持系统都具有较好的分形特性;其次,各分维指标能够准确地刻画城市游憩场点系统及交通道路支持系统的结构分异,可以为游憩场点系统的结构优化提供标准依据并指明方向;其三,苏州游憩场点系统的等级结构和空间结构均呈现出一种核心松散、外围紧致的结构递变趋势,自组织能力的离心化现象比较突出;最后,从分形几何和系统论的角度揭示、证实了游憩场点系统和旅游景点系统在结构分形及自组织演化上存在着显著差异。

The hierarchical and spatial structures of recreation sites in Suzhou city are studied during the socioeconomic transformation in China using fractal theory and methods. The system of recreation sites are divided into three recreation subsystems in the ancient city, new city and outer city areas, which are the three levels of urban regional structure based on the 2008 general planning of Suzhou city. Then, using the Zipf fractal dimension, spatial correlation dimension and traffic length-radius dimension as indexes, the hierarchical, spatial and traffic structures of the recreation sites are studied separately. It is found that both the recreation site system and transportation system of Suzhou city have good fractal characteristics. The fractal index depicts recreation system structure well and can be used for its optimization. Both the hierarchical and spatial structures of Suzhou city exhibit a gradient tendency from a loose core to a compact extended structure. Meanwhile the decentralization phenomenon of self-organization ability is distinct. Accordingly, the tracking analysis of structure evolvement of recreation site system and its optimization, as well as the strengthening guidance and improvement of its self-organization ability, are necessary for the harmonious urban planning and development. In addition, combining the previous research conclusions about the fractal in tourism, the result reveals and verifies the significant differences between fractal structure and self-organization evolvement in both recreation site system and tourism attraction system.