arXivDaily arXiv每日学术速递 周一至周五更新
arXiv周末暂无论文更新,休息一下吧,周末愉快~~
arXiv 1809.05810physics.soc-ph
收藏

城市形态的分形建模与分维描述

Fractal Modeling and Fractal Dimension Description of Urban Morphology

Yanguang Chen

摘要:

传统的数学方法都是基于特征长度的,而城市形态在很多方面都没有特征长度。城市面积是一种尺度依赖性的度量,它反映了城市形态的无尺度分布。因此,基于特征长度的城市描述应该被基于尺度的城市表征所取代。分形几何是城市尺度分析的有力工具。分形参数可以由熵和关联函数定义。然而,如何理解城市分形仍然是一个悬而未决的问题。运用逻辑推理和分形理论的思想,对城市景观的分形和分维进行了探讨。本工作的要点如下。首先,城市形态可以看作是前分形而不是真正的分形,城市的分形性质只在一定的尺度范围内有效。第二,基于城市面积的城市分形的拓扑维数为0,因此分形城市的最小分维数值等于或大于0。第三,用城市形态的分维代替城市面积,并将城市分形定义在二维嵌入空间中,得到城市形态的最大分维值为2。可以得出这样的结论:城市形态可以作为一定尺度范围内的分形进行探索,分形几何可以应用于城市形态无尺度方面的空间分析。

英文摘要:

The conventional mathematical methods are based on characteristic length, while urban form has no characteristic length in many aspects. Urban area is a measure of scale dependence, which indicates the scale-free distribution of urban patterns. Thus, the urban description based on characteristic lengths should be replaced by urban characterization based on scaling. Fractal geometry is one powerful tool for scaling analysis of cities. Fractal parameters can be defined by entropy and correlation functions. However, how to understand city fractals is still a pending question. By means of logic deduction and ideas from fractal theory, this paper is devoted to discussing fractals and fractal dimensions of urban landscape. The main points of this work are as follows. First, urban form can be treated as pre-fractals rather than real fractals, and fractal properties of cities are only valid within certain scaling ranges. Second, the topological dimension of city fractals based on urban area is 0, thus the minimum fractal dimension value of fractal cities is equal to or greater than 0. Third, fractal dimension of urban form is used to substitute urban area, and it is better to define city fractals in a 2-dimensional embedding space, thus the maximum fractal dimension value of urban form is 2. A conclusion can be reached that urban form can be explored as fractals within certain ranges of scales and fractal geometry can be applied to the spatial analysis of the scale-free aspects of urban morphology.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑