土壤水盐空间异质性及尺度效应的多重分形

为了揭示研究区域林地内土壤含水率和电导率的空间分布特征及尺度效应，利用多重分形方法，对杨凌一林地内不同采样时间和不同采样面积下土壤含水率和电导率的空间异质性进行了研究。结果表明：3种采样面积下土壤含水率和电导率的空间异质性都分别随平均含水率和电导率的增大而减弱。随采样面积的增大，平均含水率和电导率较高时，土壤含水率的空间异质性趋于增强，土壤电导率的尺度效应不明显；平均含水率和电导率较低时，土壤含水率和电导率的空间分布都存在明显的斑块结构。不同采样时间和不同采样面积下土壤含水率和电导率的多重分形谱的形态有所差异，表明引起他们空间异质性的信息有所不同。多重分形分析能揭示出较多的采样林地内土壤含水率和电导率分布的局部信息。

Multifractal study on spatial variability of soil water and salt and its scale effect

In order to reveal spatial distribution characteristics of soil water and electrical conductivity in woodland in studied area and their scale effects, the paper studied spatial variability of soil water and electrical conductivity under different sampling time and area in woodland in Yangling with multifractal method. The results showed that spatial heterogeneity of soil water and electrical conductivity under three kinds of sampling area decreased with the increase of average water content and electrical conductivity. As sampling area increased, when average water content and electrical conductivity were high, spatial heterogeneity of soil water became large, and scale effect of soil electrical conductivity was not obvious; when average water content and electrical conductivity were low, their spatial distribution had obvious patch structure. Multifractal spectrums of soil water and electrical conductivity were different under sampling time and area, which indicated that their spatial heterogeneity were caused by different information. Multifractal analysis could reveal more local information of soil water and electrical conductivity in sampling woodland.