亚太发展中国家三大城市景观格局梯度动态与城乡融合区特征

Landscape pattern gradient dynamics and desakota region features of three mega-cities in Asia-Pacific developing countries

以亚太地区3个大城市中国上海、菲律宾大马尼拉和越南河内为对象,在3S(GIS,GPS,RS)技术支持下,选取了近20年的遥感资料,采用基于斑块密度等6种景观指数的景观格局梯度分析的手段,研究了这3座城市城市化的景观格局动态及与之相关的城乡融合区特征。结果表明:在城市化过程中,这3座城市城市化区域景观格局都有显著变化,斑块密度升高,破碎化加强;在样带上,斑块密度、Shannon多样性等指数与到市中心的绝对距离有较强的相关性,景观指数能检测出城市化的梯度和城市化的推进方向;3座城市的城乡融合区有着不同的发展特征,城市化呈现出不同的发展阶段特点。大马尼拉市城市化阶段最高,郊区城市化也最早,城乡融合区明显,上海市城市化阶段较高,郊区城市化和城乡融合区也较为明显,而河内的城市化阶段较低,郊区城市化和城乡融合区不明显。需要对城市融合区的生态环境加以保护。

With the support of 3S （GIS, GPS and RS） technology and based on recent 20 years remote-sensing data, the landscape pattern dynamics and desakota region features related with the urbanization of three mega-cities in Asia-Pacific Region, i. e. , Shanghai （ China）, Metro Manila （the Philippines）, and Hanoi （Vietnam）, were studied by gradient analysis with six landscape matrix indices including contagion index, largest patch index, landscape shape index, perimeterarea fractal dimension, patch density, and Shannon diversity index. In the process of urbanization, the regional landscape pattern of the three cities changed markedly, with an increase of patch density and fragmentation. In land use transects, the patch density and Shannon diversity index had higher correlations with the absolute distance to city center. Landscape index could detect the gradient and the direction of urbanization. The desakota regions of the three cities had different development features, and the urbanization process of the cities was at different stages. Metro Manila was found at the highest stage of urbanization, and with the earliest suburb urbanization and obvious desakota region. Shanghai was demonstrated a high degree of urbanization, and an obvious suburb urbanization and desakota region. In contrast, Hanoi had lower level of urbanization and unobvious suburb urbanization and desakota region. Ecological environment protection for the desakota regions should be strengthened.