基于多重分形理论的土壤水非均匀流动分析

通过显色示踪方法研究了粘土土质、不同边界条件下的非均匀流动模式。20,40,60和80 mm的4组入渗水量条件下流动模式由面积较小的优先流逐步过渡到局部和全局性基质流,采用最大入渗深度分布和实际入渗深度分布对非均匀流动进行了特征,4组试验非均匀流动均具有多重分形性质,多重分形谱与流动非均匀性具有显著的关系,非均匀流动多重分形谱的基本性状由土壤介质性质决定,而流动的非线性主要影响多重分形谱曲线形状。

Analysis of the heterogeneous soil water flow based on the multifractal theory

Heterogeneous soil water flow was investigated by using the iodine-starch staining patterns.The field experiments were conducted at four plots with ponding water depths of 20,40,60,and 80 mm,respectively.The stained patterns of soil profiles show that soil water flow changes from the preferential flow with a few flows path and low stained coverage to the homo-geneous infiltration of the decreased unstained areas with the increase of ponding water depths.The redistribution of infiltration water is mainly influenced by the stained patterns.Flow patters are characterized by using the distributions of the maximum and actual depths.The heterogeneous soil water flow patterns from the four experiments show the multifractal nature.The flow heterogeneity is closely correlated to the multifractal spectrum.The constitutive properties of the fractal spectrum function are determined by the soil texture,whereas the range and shape of the function are affected by the nonlinearity of the heterogeneous flow.