漓江流域1973—2013年景观格局动态变化研究

Dynamic Changes of Landscape Pattern in Lijiang River Basin from 1973 to 2013

基于1973-2013年Landsat遥感影像数据,借助3S技术,分析漓江流域景观格局演化特征。结果表明,40a间漓江流域林地、建设用地、裸地持续增加,农田不断减少,水域先增后减,草地先减后增,2000-2013年整体动态度达最高值,景观变化剧烈,类型转化频繁;从景观水平上看,1973-2000年景观破碎度不断加剧,斑块复杂性升高,2000-2013年景观破碎度降低,斑块趋向于规则化;从类型水平看,林地和建设用地破碎度先升后降,斑块间距离减少,聚集程度增加;农田破碎化加剧,趋向分散经营;水体的聚集度较高,以集中分布为主;草地斑块空间关系变化不明显,分布较为均衡;裸地趋向于集中分布。受退耕还林、林果种植以及城镇扩张和旅游开发等因素的驱动,各景观类型主要向林地和建设用地转移。

Based on remote sensing images of Lijiang River basin in 1973,1986,2000 and 2013, dynamic changes of landscape pattern were studied by 3S techniques. The results showed that woodland,construction land and bare land increased while farmland decreased, and water body increased first and then decreased,whereas the grassland decreased first, and then increased in the past 40 years. The peak value of comprehensive dynamic degree appeared at 2000-2013, indicating dramatically changes of landscape in the study area. From the view of the landscape level, the fragmentation degree and patch complexity increased during 1973-2000 ,while during 2000-2013 ,the trend was opposite. From the view of landscape type level, the fragmentation degree of woodland and construction land decreased after increasing, the distance between different patches reduced and aggregation degree increased; the fragmentation degree of farmland increased and tended to be managed separately; water body presented higher aggregation index,and in concentrated distribution; grassland had little changes in spatial relationship,and presented balanced distribution; and bared land tended to present concentrated distribution. Different landscape types mainly converted into the woodland and construction land because of the influences of the factors such as the implementation of policy of converting farmland into forestland, the planting non-timber forest trees, urbanization, and tourism development.