土地利用/土地覆被镶嵌体的分形结构模型研究

Fractal Model Study on Mosaic Structure of Land Use/Cover

运用分形理论对四川省汶川县土地利用/土地覆被镶嵌体景观类型的分维值进行计算,并讨论了各种景观类型的分维性质。结果表明:土地利用/土地覆被镶嵌体具有统计意义上的自相似性,是一种随机分形结构;景观类型的分维值越大,其形态越复杂,反之越简单。SI(稳定性指数)>0,表示景观在其形态复杂状态下的一种稳定性,SI越大,该景观形态越稳定;反之亦然。SI<0,表示景观在其形态简单状态下的一种稳定性,SI越小,该景观形态越稳定;反之亦然。景观类型的分维值随时间变化而增大,该景观的形态变得复杂,反之,该景观形态变得规则。土地利用/土地覆被镶嵌体的分维值是研究土地利用/土地覆被镶嵌体景观格局的一种综合性的定量指标。

Fractal dimension values of each landscape of the mosaic structure of land use and land cover are calcu- lated at Wenchuan county in Sichuan province. Properties of fractal dimension of each landscape and their changes are discussed. It is indicated that the mosaic structure of land use and land cover has statistical self-similarity and its fractal dimension value is a kind of random fractal geometry by the research. Bigger fractal dimension value in- dicates that the spatial configuration of a landscape is more complex, whereas its spatial configuration is simpler. The stability index of a landscape bigger than zero means that the stability of landscape spatial configuration under complex state. The bigger the value of SI is, the more stable.the spatial configuration of a landscape is vice verse. The stability index of a landscape smaller than zero means that the stability of landscape spatial configuration un- der simple state. The smaller the value of SI is, the more stable the spatial configuration of a landscape is; vice verse. The spatial configuration of a landscape gets more and more complex if the fractal dimension value increases with time, whereas its spatial configuration gets simpler and simpler. The quantity fractal dimension is a compre- hensive index to study landscape pattern of the mosaic structure of land use and land cover.