| In recent years, preferential flow was a new concept in the soil water movement, it is a common form of soil water movement, and is closely related to soil water infiltration, surface water quality and water quality. Macropore flow is a typical preferential flow. It has a very significant impact on the migration of contaminants within the soil, as macropores are prevalent of in soils, water and solute have priority moving through these macropore channels. In this paper, water movement and solute transport in unsaturated soil with imitated macropore regions were studied through indoor physical model experiments, mathematical model analysis, the concept of macropores' depth and the effective surface macropores were analyzed for the impact of macropores region on the water and solute transport in unsaturated soil. Major findings are as below:(1) Proposed the quantitative calculation of the simulated macropore characteristic elements, including macropores'depth and the effective surface, calculation results agreed with logical. Produced the different depths and effective surface macropores region useing special experimental equipments and molds filled with different particle size of sand.(2) Analyzed water infiltration priority migration laws in unsaturated soil with simulative macropores, including the same effective surface macropores (Φ= 1.8370%) and different simulative depths macropores regions. Reached a conclusion that the characteristic turning point time, the cumulative infiltration volume, featured wetting front, the instantaneous infiltration rate have significant migration characteristics of the priority in unsaturated soil with simulative macropores. Proposed the concepts of water infiltration increment and the increment of infiltration under unit macropores'area in unsaturated soil with different depths'of macropores, and conducted quantitative analysis and tedting.(3) Analyzed water infiltration priority migration laws in unsaturated soil with simulative macropores, including the same simulative depths macropores regions and different effective surface macropores. After analyzing the experimental data, we established a quantitative relationship among the characteristics turning point time, cumulative infiltration, and characteristic wetting front with the effective surface macropores in the process of the water infiltration, and results were verified.(4) Analyzed the change of the discharge water volume and solute concentration from the process of water and solute infiltration in unsaturated soil with different depths and different simulated effective surface macro pores, established a quantitative mathematical model among the simulated macropores'depths, the effective surface macropores and the cumulative discharge of water and solute. We obtained the pattern of vertical and radial distribution of solute concentration under the experimental conditions in unsaturated soil with macropores region. The results showed that the vertical distribution of solute concentration has double peaks and reduced migration time along the soil depth. The radial distribution of solute concentration increased from the center of macropores radially in the unsaturated soils with simulative macropores.(5) A simplified conceptual model was established a conceptual model for water transport in unsaturated soil with simulative macropores region. We soluted the mathematical model with the initial and boundary conditions by ADI difference method. We simulated the characteristic wetting front and the wetting front sector on infiltration process using the mathematic model HYDRUS-2D, and compared with the measured value. The results showed that the simulated values and measured values agreed well.
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