近30年广州市土地覆被变化时空特征分析

Spatio-temporal Characteristics of Land Use and Cover Change in Guangzhou City in the Past 30 years

以1979、1990、2002和2006年4个时相的遥感数据为主要数据源，利用遥感图像处理软件ENV14．4对影像进行预处理，在ArcGIS9．2软件的支持下提取城市土地利用斑块，比照广州市土地利用现状图，结合实地调查，建立土地利用数据库，揭示广州市土地覆被变化时空特征，旨在为改善城市生态环境，提高土地利用效率提供科学依据。研究结果表明：广州市近30年土地覆被类型以林地、农田、建筑用地为主，农田和裸地逐年减少，人地矛盾突出；20世纪90年代后期以来，林地、水域面积小有增加，生态环境保护的政策效应初步显现。土地覆被类型的变化速率呈现先快后慢趋势。1979～2002年是土地类型变化剧烈，变速较快的时期，平均变化率为36．55％。2002—2006年期间，随着民众环保意识的普遍提升，加之各项政府政策的逐步落实，可开发土地面积的逐步减少，土地变化速率趋于平缓。

Four TM remote sensing images of Guangzhou in 1979, 1990, 2002 and 2006 are taken as data for the study. The images fully cover the area of Guangzhou. The data sources of land-cover landscape are translated under supervised and un-supervised interpretations with Envi4.4. By using ArcGIS 9.2 software to extract urban land use speckle and contrast land use map of Guangzhou City. Through investigation to create land use data- base, the analysis demonstrated spatio-temporal characteristics of land use so as to improve urban eco-environment and land use efficiency. The research demonstrates that forest and water area increase during the past 30 years and environment protect policy has the obvious effect. The ratio of land use to cover change has the characteristics of fast in beginning and slow in recent years. In the 1979 -2002 the change of land use was rapid and the average change rate was 36.55%. In the 2002 -2006, with the improvement of protect environment and other policy induces the ratio of land use turned into be stable.