城市边缘区土地利用结构分形特征的动态变化——以广州市南拓区为例

Dynamic Change of Land Use Structure Fractal Characteristics of Urban Fringe:A Case Study in the Extend South Area of Guangzhou

近20年来,随着广州市城市化水平的大幅提升,作为城市地域空间发展前沿的城市边缘区土地利用变化异常明显。本文以广州市典型城市边缘区为研究对象,基于覆盖广州市南拓区的4时相TM遥感解译数据,构建土地利用数量结构变化模型和分形结构模型,定量化研究区域土地利用结构的变化强度、复杂性和稳定性。研究结果表明:在广州市核心区城市化辐射作用下,南拓区1990年以来,土地利用经受了剧烈的变化,按照变化特征可将其分为2个阶段:(1)前期(1990-1995年),土地利用结构变化剧烈,建筑用地的增加和耕地面积的减少主导了该时期的土地利用数量变化过程,期间分维数快速增加,稳定性迅速下降;(2)后期(1995-2005年),土地利用结构变化幅度减缓,耕地、林地面积有所回升,分维数和稳定性上升幅度趋缓,区域土地利用结构变化开始出现良好的态势。

Over the past two decades,with rapid urbanization in Guangzhou,urban fringes experienced drastically land use changes.In this paper,taking the Extend South Area of Guangzhou as a typical example of urban fringe,based on GIS（Geography Information System） and RS（Remote Science） technology,land use vector of the study area in 1990,1995,2000 and 2005 were interpreted from Landsat TM images.Dynamic degree,fractal dimension and stability index of each main land use type in each year were calculated.Results showed that： from 1990 to 2005,land use of the Extend South Area of Guangzhou experienced obvious changes under the strong forces of urbanization of core area in Guangzhou.According to the change characteristics of land use,two phases of study period are followings.Firstly,from 1990 to 1995,the structure of land use changed tempestuously.In this period,the increase of construction land and decrease of farmland was the main process,with great increase of fractal dimension and decrease of stability index.Secondly,from 1995-2005,increasing speed of construction slowed down,farmland and forest land started to increase,and increase of fractal dimension and stability index became slighter,regional structure of land use experienced a beneficial development.