海湾型城市半城市化地区空间扩展演化——以厦门市为例

选择海湾型城市--厦门市半城市化地区为研究对象,基于研究区1987、1992、1997、2002和2007年5个时相的TM/ETM+遥感影像数据,在遥感与GIS技术支持下获取了近20a 来各期土地利用信息数据,采用景观格局转移矩阵、景观格局指数和分形理论等方法研究了厦门市半城市化地区城市化过程中的景观格局空间演变特征,详细分析了城市形态演变、城市围填海特征及政策影响.结果表明:20 a 年来厦门近郊建设用地从18.4 km2增加到108.4 km2,远郊则从35.7 km2增加到114.9 km2,分别增长为原来5.9倍和3.2倍;城市空间扩展过程通过不断侵蚀耕地、林地和大规模填海造地完成,其中耕地景观变化最大,城市扩展最高峰(2002～2007年)近郊与远郊被建设用地"蚕食"的耕地多达19.74 km2和33.11 km2;在城市空间不断扩展的过程中,近郊城市城市由不稳定形态逐步向稳定形态(填充增长)演化,但远郊形态格局尚处于以中心城市扩展为主体的时期;填海造地面积及其时空分布与政策因素密切相关,20 a来厦门半城市化地区海岸线缩短了14.3%,近郊与远郊海岸分维数分别从1.236和1.267降到1.191和1.262,岸线复杂性明显降低,逐步趋于平直;海湾型城市战略的提出对填海造地影响最为明显,2002～2007年期间填海进程明显加快,近郊与远郊分别填海13.32和9.15 km2,超越了前15 a 填海总面积.

Analyses of peri\|urban landscape dynamics in the rapid urbanizing process: a case study of Xiamen

The evolution of the peri\|urban landscape pattern of Xiamen over its rapid urbanization period from 1987 to 2007 was studied through the analyses of landscape transfer matrix, landscape indexes, and fractal method (box counting method). Based on RS and GIS techniques, five Landsat TM/ETM+ images, acquired respectively in 1987, 1992, 1997, 2002 and 2007, were used to construct landuse database for the studied area. The result shows that construction land area increased rapidly from 18.4 to 108.4 km2 in the suburb and from 35.7 to 114.9 km2 in the exurb over the 20\|year period. The urban expansion mainly occupied forestland, farmland, and sea. Farmland area decreased dramatically and had lost 19.74 and 33.11 km2 in the suburb and exurb, respectively, between 2002 and 2007 alone. While the urban expansion morphology has become stabilized in the suburb districts, it remains unstable in Xiamen exurb areas. Coastal reclamation effort in this region has been governed by policies in various phases. The coastal line tended to be simplified and straightened with fractal dimensions decreased from 1.236 to 1.191 and from 1.267 to 1.262 for the suburb and exurb, respectively. The recent government decision to transform Xiamen from an island city to a bay city had an important effect on coastal reclamation and had added 13.32 and 9.15 km2 of reclamation areas in suburb and exurb, respectively, over the 5 year period from 2002 to 2007, more than the total area reclaimed over the 15 years from 1987 to 2002.