1986-2006年桂林市区景观格局演变分析

Study on Landscape Dynamics of Guilin City from 1986 to 2006

以遥感影像为主要数据源,利用3S技术,对1986—2006年间桂林市区景观格局变化进行分析。结果表明:20a间,桂林市区林地、建设用地、裸地呈增加趋势,农田、草地、水体呈减少趋势,建设用地的变化速度最快,景观变化最剧烈;从景观水平上看,斑块数、聚合度、多样性和均匀度指数呈增加趋势,平均斑块面积、边界密度、面积加权分维数和结合度呈降低趋势。从类型水平上看,林地破碎化降低、自然特征增加;农田破碎化加剧、趋向于分散经营;建设用地破碎化增加、集中化趋势明显;水体破碎化、复杂性均有所增加;草地变化剧烈。退耕还林政策的实施、果业种植和乡村旅游的发展、城镇扩张以及农业开发活动是景观格局演变的主要驱动因素。

Based on the Landsat TM images, changes of landscape pattern of Guilin City from 1986 to 2006 were studied by using ＂3S＂ techniques. The results showed as follows： the woodland, construction land and bare land increased, while the farmland, grassland and water body decreased in Guilin City over the past 20 years. The change of construction land was the fastest, most intensive and frequent among all landscape types. At the level of landscape, the number of patches（NP）, aggregation index（A1）, Shannon＇s diversity index（SHDI） and Shannon＇s evenness index（SHEI） increased, while mean patch area （AREA_MN）, edge density（ED）, fractal dimension area weighted mean （FRAC_AM） and patch cohesion index（COHESION） decreased in this area. At the level of landscape type, fragmentation of the woodland reduced and natural fea- tures were strengthened; fragmentation of farmland increased and tended to be separately managed; fragmen tation of construction land increased and had a trend of obvious centralization; fragmentation and complexity of water body both increased; and the change of grassland was intensive. The implementation of the policy of the conversion of farmland into forestland, the planting of fruit, the rapid development of rural tourism, ur ban sprawl and agricultural activities were the main driving factors of the dynamic changes of landscape pat tern in Guilin City.