土壤水分扩散率单一参数模型空间变异及尺度效应的多重分形

Multifractal of Spatial Variability and Scale Effects on Single Parameter Model of Soil Water Diffusivity

在试验的基础上,建立了杨凌及其周边地区0~20 cm土层和20~40 cm土层非饱和土壤水分扩散率的单一参数模型,并运用统计学原理和多重分形方法对不同土层单一参数模型中参数S的空间变异规律和尺度效应进行了分析。结果表明：0~20 cm土层和20~40 cm土层参数S都属于中等变异程度;0~20 cm土层和20~40 cm土层参数S的空间分布格局的多重分形特征都比较明显,但0~20 cm土层参数S在空间上的变化更加复杂;0~20 cm土层和20~40 cm土层参数S的多重分形谱的宽度分别为0.2667和0.2158,都呈现不同程度的左偏,说明不同土层参数S的空间变异性比较强,且都主要是由高值分布引起的。多重分形分析能够揭示出研究区域内不同土层参数S分布的较多局部信息。

On the experiment basis, a single parameter model of unsaturated soil water diffusivity was constructed at 0- 20 cm and 20- 40 cm soil layers in Yangling and nearby area. Spatial variability and scale effects of parameter S in the single parameter model from different soil layers were analyzed using statistical theory and multifractal method.The results showed that the parameter S in 0- 20 cm and 20- 40 cm soil layers all belonged to the medium degree of variation; spatial distribution pattern of parameter S had obvious multifractal characteristics in 0- 20 cm and 20-40 cm soil layers, however, it was more complex in spatial variability of parameter S in 0- 20 cm soil layers.Multifractal spectrum width of parameter S in 0- 20 cm and 20- 40 cm soil layers were 0.2667 and 0.2158,respectively, which all showed varying degrees of left side, and indicated that parameter S of different soil layers had strong spatial variability that mainly caused by the high distribution. Multifractal analysis could reveal more local information of parameter S from different soil layers in study area.