Fractal analysis of urban form as a tool for improving environmental quality

Abstract

With the development of Lijiang City, many empty spaces have been exploited and the built-up land is becoming increasingly crowded. This has caused degradation of the urban environment. In this paper, we analyse the fractal dimension of built-up land in Lijiang City in an attempt to improve environmental quality. TM image data acquired in 2000 and 2006 were used to derive land-use data through a back-propagation neural network realized using Matlab software. Urban form was quantified with the box-counting method. The fractal dimension of built-up land increased from 1.73 in 2000 to 1.84 in 2006, meaning that the respective amounts of built-up land and green space have become disproportionate over time. To obtain a better balance between green areas and built-up land, the area–radius relationship method and the Smeed model were used to find the optimum range, within which increasing green areas will bring greater ecological benefits. This range was within a 2000-m radius of the entrance to the Old Town of Lijiang. Increasing green areas in this range is recommended to increase ecological benefits to the whole city, and the emphasis of planning studies in Lijiang City in future should be on the rational layout of built-up land within this range.

Keywords:

• remote sensing
• fractal
• built-up land
• green space
• urban environment

Acknowledgement

This study was supported by the Chinese Academy of Sciences (KZCX2-YW-453, 08I4071D10 and D-2009-02) and the CAS/SAFEA International Partnership Program for Creative Research Teams (KZCX2-YW-T08).