Abstract:Based on the theory of unsaturated soil water dynamics, the soil water distribution under vertical line source infiltration was analyzed by the software Hydrus-2D. The model was testified by the experiments and soil hydraulic parameters were estimated. The result showed that this model could be used to simulate soil water infiltration characteristics with certain accuracy. The characteristics of water distribution under line source irrigation were simulated concerning different irrigation technique factors. The results showed that, under the condition of line source irrigation, the shape of wetting patterns under different soil textures was similar, and the scale was different: the ratio between the maximum sand loam and clay loam’s level wetting radius and sand’s were 0.59 and 0.24, the ratios of vertical humid depth were 0.42 and 0.31; on the condition of different line source depth, the shape and scale of wetting patterns were similar, and the positions had great difference, when the depth increased 5cm, the vertical humid depths of sand, sandy loam and clay loam were increasing by 6%, 11.5%, 16% separately; the length and the diameter of the line source had conspicuous influence on soil water distribution, the length had a major impact on the vertical humid depth, the diameter had a primary influence on horizontal wetting radius; when the initial water Symbol`content was high, the water content in the same cross-section increased; in the same period of irrigation time, the wetting front distance of level and vertical increased with the increasing of initial water content.
