云南宣威市集镇体系分形特征及影响因素

基于熵值法对集镇规模量化评价,以位序—规模法则、聚集维数、网格维数、关联维数为方法的宣威市集镇体系分形研究表明:①集镇体系规模和空间结构都具有明显分形特征,但也存在分形发育不完善等问题。②集镇体系规模分布分散,兼具“发育不足”和“差异显著”双重特征,向心性与城镇体系相异、均衡性差、交通联系薄弱,呈“小聚集”形态分布于河谷、交通线及坝区,“多圈层”、“多中心”和“低海拔指向”特征明显。③分形发育受自组组织力量交织影响,“山、河、坝”相间分布的地理环境是集镇体系分形的基础支撑,交通因素是分形发育的控制变量。可利用分形理论进行聚落体系规划,扶持重点集镇、改善交通条件促进集镇体系优化。

Fractal Characteristics and Influencing Factors of Market-Town System in Xuanwei City of Yunnan

This paper quantitatively evaluates the market-town scale applying the entropy method and analyzes the fractal characteristics of the market-town system in Xuanwei City by the methods of rank-size rule, aggregation dimension, grid dimension and correlation dimension. The results show: 1) The scale and spatial structure of the market-town system have obvious fractal characteristics, but there are also some problems such as imperfect fractal development;2) The distribution of the market-town system scale is dispersive and has dual prominent characteristics of underdevelopment and difference, its centripetal character is different from the urban system, the balance of spatial distribution is poor and the traffic contact is weak. Market-town mainly distributes in the valley, the traffic line and the flatland areas, markettown system has obviously multiple-layer, multiple-center and low-altitude characteristics;3) The fractal development of market-town system is influenced by self-organization and heter-organization forces. The interphase distribution of the mountains, rivers and flatland areas is the foundation of the fractal development of the market-town system. Traffic factor is its control variable. The fractal theory can be used to the settlement system planning, and it can promote the optimization of the market-town system by supporting key market-towns and improving traffic conditions. The study shows a theoretical perspective and practical basis for the current rural revitalization strategy and the planning of mountain villages and towns.