Characterizing scale-dependent heterogeneity of soil water movement through dying infiltration experiments

To address the flow heterogeneity issue,the objective of this study are to investigate heterogeneity of soil water flow at different measurement scales using dying infiltration experiments and characterize the heterogeneity information included in different scales with the random cascade model. The random cascade model with a lognormal distribution is used to simulate the infiltration process in soils,and the different methods are applied to estimate the model parameters. Results based on the experimental data and the model simulations show that the measurement scale is important factors affecting the flow patterns in soils. To accurately describe flow transport processes at different scales,it is necessary to consider heterogeneities in the vertical and horizontal directions. As the measurement scale increases,the effect of multi-dimensional heterogeneities on the flow processes in soils becomes more significant.