广州市城乡交错带土地覆被景观格局时空分异

Temporal-spatial Grading Diversification of Landscape Pattern of Urban-rural Ecotone in Guangzhou

基于1990、1995、2000和2005年覆盖广州市南部拓展区的LandsatTM遥感影像,经监督分类和人工目视解译获得研究区各时相土地覆被景观图。选取景观指数指标对研究区的景观格局和动态变化进行研究,并利用缓冲区技术研究分析各时期内景观特征的梯度方向分异。结果表明:广州市南部拓展区在15年间景观格局发生了重大变化,该时期内景观的破碎化程度逐年增大,景观异质性先增后减,优势斑块呈分散趋势;耕地面积先减后增,总体呈下降趋势,而建筑用地面积则逐年上升;景观格局梯度分析显示区域景观格局存在方向上的梯度分异,反映大城市中心区不同辐射距离范围内城乡交错带的城市化发展差异。

Based on GIS and RS technology, the remote sensing images of land-cover in developing area of southern Guangzhou, which was one of the urban-rural ecotones in the city, were translated under manual and supervised interpretations. The images include those of Landsat TM of 1990, 1995, 2000 and 2005. According to landscape ecology theory, a series of landscape indices, such as PD, SHDI, FRAC_MN, CONTAG, PN, LSI, were computed to analyze the dynamics and characteristics of the land-cover landscape in developing area of southern Guangzhou, and gradient analysis with landscape indices in each buffer zones was combined. The results show that the land-cover landscape pattern, as a kind of typical urban-rural ecotone, changed dramatically during 1990-2005 under the great human influence, the fragmentation of landscape pattern became higher, the area of farmland and forest land decreased sharply from 1990 to 2000 and then increased. Though the area of built-up land increased year by year, the increasing rate slowed down after 1995. Urbanization of the studied area experienced a process of excessive land-use. The characteristics of landscape pattern in different buffer zones showed grading diversification, which indicated the difference of urbanization development of urban-rural ecotone was influenced by radiation distance of the center of megapolis.