基于景观生态视角的兰州市城市化空间模式定量研究

Quantitative study on urban spatial pattern of Lanzhou city from the perspective of landscape ecology

以1994、2000、2006和2010年夏季的Landsat TM/ETM影像为数据源,利用ENVI4.5、ARCGIS10、Fragstas3.3软件,从景观生态角度,选用斑块密度、边界密度、景观形状指数、香农多样性指数和蔓延度指数,定量分析了兰州市的城市化空间模式,结果表明:1)城市化进程中,城市的空间发展是以外部扩张和内部填充两种形式实现的;2)兰州市1994到2010年建成区面积急剧增加,边界密度、景观形状指数、香农多样性指数随之上升,蔓延度指数不断减少,1994到2006年斑块密度不断增加,说明1994到2010年间,兰州市主要以外部扩张为主,内部填充为辅;3)从2006到2010年斑块密度下降的趋势,可以看出,未来几年,兰州市城市空间发展可能会转化到以内部填充为主,外部扩张为辅的阶段。

In this paper we quantificationally analyzed the urban spatial pattern of Lanzhou city from the perspective of landscape ecology based on 1994-2010 TM/ETM images with ENVI4.5,ARCGIS10,Fragstas3.3 softwares.The Landscape indices chosen include patch density,edge density,landscape shape index,Shannon＇s diversity index,contagion.The results include the following several aspects.Firstly,urban spatial expansion was accompanied by external expansion and internal filling in process of urbanization.Secondly,from 1994 to 2010,the build-up area has increased dramatically.Edge density,landscape shape index and Shannon＇s diversity index were becoming bigger.Contagion index decreased continually.From 1994 to 2006,patch density became bigger and bigger.The changes of all indices showed that urban spatial expansion was mainly external expansion supplemented with internal filling from 1994 to 2010.Finally,there was a trend toward low of patch density from 2006 to 2010.In future,Lanzhou city＇s spatial development may shift to internal filling mainly,supplemented by external expansion.