基于TM影像的衡阳市城区扩展趋势研究

A Study on Urban Sprawl in Hengyang City Based on TM Image

城镇化是我国经济发展必然产物,城市扩展是城镇化进程的一个重要指标。遥感技术具有快捷、便利、大面积同步观测等特征,已经广泛应用于对城市扩展的监测。以衡阳市为研究对象,选取该区域1989年、2006年和2010年的Landsat TM遥感影像作为数据源,利用植被、水体和建筑物指数特征和监督分类方法提取3 a(年)中衡阳市城区边界信息,最后采用GIS的空间分析技术,从扩展强度、扩展方向2个方面来讨论衡阳市城区的扩展空间特征。

Urbanization is an inevitable product of economic development in our country,while urban sprawl is an important indicator of urbanization process.The characteristics of Remote sensing technology is fast,convenient,large area synchronized observation which has been widely used in the monitoring of urban sprawl.This paper,firstly,taking Hengyang city as the study object,choosing Landsat TM remote sensing image of the region in 1989,2006 and 2010 as data sources,utilizes vegetation,water and build-ing,characteristic indexes and supervised classification method to extract three years′city boundary in-formation of Hengyang.Secondly,using GIS spatial analysis technology,discusses the space characteris-tics of urban sprawl in Hengyang city from two aspects which are the extension strength and the extension direction.