地貌形态特征分形信息维数与像元尺度关系研究

Relationship between fractal dimensions of watershed topography characteristics and grid cell size

本文论述了用分形信息维数(FID)表征流域地貌形态特征的原理和方法;建立了基于GIS平台流域地貌特征分形信息维数的计算模型;并利用Avenue语言开发了基于Arcview环境下流域地貌特征分形信息维数计算软件。以长江弹子溪小流域为例进行地貌分形信息维数的计算,依据计算数据就地貌形态特征分形信息维数与像元尺度关系进行了分析。结果表明:流域地貌分形信息维数可以较好地作为流域复杂地形地貌形态特征综合性、整体性和科学性的量化指标;像元尺度对地貌分形信息维数的无标度区间确定十分关键;跨流域地貌形态特征分形信息维数计算与评估应以统一像元尺度为前提。

The theory and method for describing the topographic characteristics of watershed by using fractal information dimension (FID) are introduced and the mathematical model based on GIS platform is proposed. The software under the circumstance of Arcview is developed and the calculation result of an example is given. It shows that the fractal information dimension can be used as a quantitative index to comprehensively describing the complicated topographic characteristics of the watershed. The size of grid cell plays important role in determining the non-scale range of FID. The calculation and evaluation of FID for inter-watershed topographic characteristics should be based on the same grid size.