干热河谷区土地利用/覆被和景观格局变化分析——以得荣县为例

利用1993、2000和2009年3个时期土地利用数据,将GIS和景观生态学的数量分析方法相结合,运用Arcin-fo以及Fragstats(栅格版),分析了干热河谷区得荣县1993-2009年间的土地利用/覆被和景观格局的变化。结果表明:研究期间,林地和耕地大幅度减少,草地和建设用地面积显著增加,水域相对变化幅度不大。研究区土地利用类型转移的主要方向是林地转化为草地、耕地转化为建设用地和草地、草地转化为未利用地。通过对该区斑块类型级别指标的分析,得出水域、建设用地分离度和破碎度较大,而耕地、林地和草地在宏观政策和人类活动强烈干扰下,分离度呈现先升高后降低的趋势。通过对景观级别指标的分析,得出整个区域景观结构先趋于破碎后逐步聚合,景观异质性先提高后下降,但总体上来看土地向着多样化和均匀化方向发展。

Analysis of Land Use / Cover and Landscape Pattern Change in the Dry-hot Valley(DHV) Area: A Case Study in Derong County

In order to understand the changes of land use / land cover and landscape pattern form 1993 to 2009 in a Derong county(a representative area of dry-hot valley),land use characteristics in 1993,2000 and 2009 were analyzed by the combined methods of GIS and the quantitative analysis as Arcinfo and Fragstats(raster version) software.The results showed that,the area of arable land and woodland were significantly decreased during the studied period,whereas the area of grassland and construction land increased,although water area displayed little changes.Land use types changed mainly from woodland to grassland,from arable land to construction land,and from grassland to unused land.According to the analysis of plaque-type level indicators,high degree of separation and fragmentation was observed in water area and construction land,while the degree in farmland,woodland and grassland presented a tendency of increasing and then decreasing due to the strong disturbances of microscopic policies and human activities.Additionally,the landscape structure of the investigated area was fragmented and then gathering gradually and landscape heterogeneity increased and then decreased.The results suggested that the land use/cover could be direct to diversification and homogenization in this area of dry-hot valley.