基于GIS的四平市城市扩展遥感分析

Research of Urban Expansion in Siping City Based On Remote Sensing and GIS

本文以吉林省四平市为例,选取1976、1979、1991、2001和2007年MSS、TM、ETM+的5个时相遥感图像,对其进行处理、解译,以城市面积变化、分维数、紧凑度等作为指标,对该市31年来城市扩展及其特点进行研究。结果表明,四平市在31年内的城市扩展可分4个阶段,其中,1979-1991年城市扩展速度最快,而2001-2007年城市扩展速度也较快,而且更注重城市的内涵建设,这与四平市经济发展情况相符合。说明城市形态指数与统计数据结合可以更充分地描述城市扩展的特征和过程。

Urbanization is a major trend in recent years all around the world.China has experienced rapid development since reform and opening-up.Therefore,urban expansion has been significant in this period.Based on the RS and GIS methods,Siping City,a medium city in Jilin Province,is selected as a study case with five remote sensing images in 31 years.After a series of image processing,the five phases of urban boundaries were acquired.It is obvious that the Siping City is partially shaped by river,roads and freeway.Then,the area-perimeter fractal dimensions are adopted to calculate fractal characteristics of urban area based on the box-counting method.After that the compact ratio is calculated to describe the shape characteristic of Siping City.In this paper,the Siping Statistical Yearbook is collected to find out the relationship between economy growth and urban expansion.The process and characteristics of urban expansion are analyzed using urban area change,fractal dimension,compactness and statistical data as well as GIS technology.The results showed that there are four stages in this period.It expended fastest from 1979 to 1991.Between 2001 and 2007,it expended fast as well and emphasized more on urban connotation construction.And this is in agreement with the Siping Statistical Yearbook.Because the urban expansion is influenced by roads,railroads and freeway,the morphology of Siping City now seems like a pentacle.The city should make full use of its traffic line which extends in all directions.All these indicate that the combination of urban morphology index and statistical data can be done to satisfactorily describe the process and characteristics of urban expansion.