黄土丘陵小流域土地利用景观空间格局动态分析

Dynamic analysis of the spatial pattern of landscape of small watershed in loess hilly-gully region

该文以上黄试区为例,在地理信息系统支持下获得计算景观多样性的有关参数,选取斑块大小及数量、分维数、斑块伸长指数、多样性、优势度、均匀度和破碎度等指标,对黄土丘陵小流域10a来景观多样性动态变化进行了分析。结果显示,耕地、林地、园地、居民点用地及草地分维数略有下降,未利用地分维数有所上升,而水域分维数保持不变。试区景观类型多样性指数和均匀度指数略有下降,优势度指数、破碎度指数及土地利用合理指数有所增加,目前试区从耕地及草地为主的景观生态系统转变为以林地和草地景观为主的高度异质化的景观生态系统。政策因素的引导及经济利益的驱动是该试区土地利用景观格局变化的主要原因。

Taking Shuanghuang experimental area as the study site, some landscape diversity indexes were attained using GIS technology. Utilizing the indexes such as patch size and numbers, average fractal dimension, diversity index, dominance, evenness and fragmentation, the changes of landscape diversity in the loess hilly-gully region during the past 10 years were studied. The results show that the patch fractal dimensions of farmland, wood land, orchard, village and meadow decrease slightly, unutilized land increases slightly, while the water area keeps invariability. The indexes of landscape diversity and evenness have the tendency of decrease while the dominance, rationality index of land use and fragmentation increase slightly. Homogeneous farmland and meadow matrix landscape ecosystem in 1995 had already changed into heterogeneous meadow and woodland matrix landscape ecosystem. The factor of policy and the drives of economic interests are the main reasons that drive the landscape pattern change.