晋江西溪流域土地利用结构变化的分形研究

Fractal Analysis on Landuse Stucture in Xixi Watershed of Jinjiang Basin

基于晋江西溪流域1985与2001年两期土地利用遥感解译数据,运用周长—面积分形方法计算获得了西溪流域两期主要地类的分形维数和稳定性指数,并对土地利用空间格局的变化进行了分析。研究结果表明,西溪流域土地利用的整体分形维数从1985年的1.255减少到2001年的1.169,整体空间结构向着简单、规则的方向发展;林地和水域的分形维数有所增加,其余用地类型均表现为减小。西溪流域土地利用的整体稳定性指数从1985年的0.245增加到2001年的0.331,用地的整体空间结构更加稳定。土地利用空间结构最稳定的地类在1985与2001年分别为林地和草地,两期最不稳定的地类均为耕地。1985—2001年,人类活动对占西溪流域面积近50%的林地的利用趋于无序,空间结构趋于不稳定,今后应重点加强对林地有序利用的规划管理。

Based on 1985 and 2001 remotely sensed land use data of Xixi watershed, Jinjiang basin, fractal di- mension and stability index of each major land use type were acquired and the change of the land use spatial pattern were investigated. The results show that the fractal dimension value of the study area decreased from 1. 255 in 1985 to 1. 169 in 2001, and the whole land use spatial structure was simplified. The fractal dimen- sion values of forest land and water land increased, while the values of the other land types decreased. The spatial structure stability index of land use in the study area increased from 0. 245 in 1985 to 0. 331 in 2001. The whole spatial structure stability of land use of the watershed tended to increase. The most stable land use types of Xixi watershed were forest land in 1985 and grass land in 2001, and the most unstable land use type was all farm land in both 1985 and 2001. From 1985 to 2001, the use of the forest land, which covers 50 percent of the total area of Xixi watershed, was out of order with an increasingly unstable spatial structure. The forest land should he planned and managed more properly from now on.