The Relationship between Soil Structure and Water Characteristics Based on Fractal Theory

In order to understand the indicative effect of soil structure on its hydraulic properties, undisturbed soil samples from the Ziya-River basin in the North China plain were selected as the research objects. The soil water characteristic curve was measured by tension meter method, and the particle size distribution of soil samples was measured by laser particle size analyzer. The fractal dimension of soil particle size distribution was calculated based on fractal theory. Soil water characteristic curve was analyzed by experimental measurement and model verification. The fractal dimension of soil particle size distribution in the range of [10 μm, 50 μm] is the key parameter to characterize the characteristics of the significant rising section of soil particle size distribution, which is significantly correlated with the fitting parameters (a, b) of the power function model of soil water characteristic curve in the suction range of 0-80 kPa. The power function model expressed by the fractal form of soil water characteristic curve in the study area is: θ=100.78×(3-D)S(D-3)/3, and the fractal characteristics of soil structure can effectively indicate its hydraulic properties. © 2021, Editorial Department of Earth Science. All right reserved.