快速城市化地区景观格局梯度动态及其城乡融合区特征——以广州市番禺区为例

以快速城市化的广州市番禺区为研究样区，通过解译1990—2008年4期Landsat TM影像得到研究区土地利用/覆被数据.选取景观类型水平和景观水平上的景观指数，采用景观格局与梯度分析相结合的方法，研究快速城市化地区景观格局的梯度变化及其城乡融合区特征.结果表明：研究区景观格局动态变化显著，在城市化缓冲带上具有典型的城乡融合区特征，城市景观逐年增加且向外围扩展，而农业景观破碎化严重.斑块密度、蔓延度、景观多样性等指数在城市化梯度上表现出明显的规律性，景观指数峰值出现在距离城市中心4～6 km的梯度带上.时间序列上的景观格局数据体现了不同梯度带上景观动态的差异，城乡融合区景观格局具有斑块形状复杂、景观多样性和破碎化程度高、景观动态变化剧烈的特点.景观指数的峰值逐年向外推移，城乡融合区有逐渐向外发展的趋势.探讨了城乡融合区景观格局时空演化的一般特征及其驱动因素，对区域土地利用政策和可持续发展规划具有指导意义.

Landscape pattern gradient dynamics and desakota features in rapid urbanization area: A case study in Panyu of Guangzhou

In order to understand the landscape pattern gradient dynamics and desakota features in rapid urbanization area, this paper took the rapidly urbanizing Panyu District of Guangzhou City as a case, and analyzed its land use and land cover data, based on four Landsat TM images from 1990 to 2008. With the combination of gradient analysis and landscape pattern analysis, and by using the landscape indices in both class and landscape scales, the spatial dynamics and desakota feature of this rapidly urbanizing district were quantified. In the study district, there was a significant change in the landscape pattern, and a typical desakota feature presented along buffer gradient zones. Urban landscape increased and expanded annually, accompanied with serious fragmentation of agricultural landscape. The indices patch density, contagion, and landscape diversity, etc., changed regularly in the urbanization gradient, and the peak of landscape indices appeared in the gradient zone of 4-6 km away from the urban center. The landscape patterns at time series also reflected the differences among the dynamics in different gradient zones. The landscape pattern in desakota region was characterized by complex patch shape, high landscape diversity and fragmentation, and remarkable landscape dynamics. The peaks of landscape indices spread from the urban center to border areas, and desakota region was expanding gradually. The general trend of spatiotemporal dynamics in desakota region and its driving forces were discussed, which could be benefit to the regional land use policy-making and sustainable development planning.