Evolution of soil-water movement patterns following rare and extreme rainfall events in arid climates is not well understood, but it has significant effects on water availability for desert plants and on the hydrological cycle at small scale. Here, field data and the Hydrus-1D model were used to simulate the mechanisms of soil water and vapor transport, and the control factors associated with temporal variability in the soil water and temperature were analyzed. The results showed that thermal vapor transport with a no rainfall scenario determined daily variability in water content at the soil surface. During rainfall, isothermal liquid water fluctuated as a result of dry sandy soils and matric potential in the upper soil (0–25 cm), and thermally driven vapor played a key role in soil-water transport at 40–60 cm soil depth. After an extreme rainfall event, thermal vapor flux increased and accounted for 11.8% of total liquid and vapor fluxes in daytime with a steep temperature gradient; this was very effective in improving long-term soil-water content after the rain. The simulated results revealed that thermal water vapor greatly contributed to the soil-water balance in the vadose zone of desert soil. This study provided an alternative approach to describing soil-water movement processes in arid environments, and it increased understanding of the availability of water for a desert plant community.

干旱气候中罕见和极端降雨事件后土壤-水运动模式的演变尚不清楚，但它对沙漠植物的可用水量和小规模的水文循环具有显着影响。在这里，利用现场数据和 Hydrus-1D 模型模拟了土壤水汽输送机制，并分析了与土壤水温随时间变化相关的控制因素。结果表明，在没有降雨的情况下，热蒸汽传输决定了土壤表面含水量的每日变化。在降雨期间，等温液态水由于干燥的沙质土壤和上层土壤（0-25 cm）的基质势而波动，热驱动的蒸汽在 40-60 cm 土壤深度的土壤-水输送中起关键作用。极端降雨事件后，热蒸汽通量增加，占白天总液体和蒸汽通量的11.8%，温度梯度陡峭；这对于改善雨后的长期土壤含水量非常有效。模拟结果表明，热水蒸气对沙漠土壤包气带的水土平衡有很大贡献。这项研究提供了一种描述干旱环境中土壤-水运动过程的替代方法，它增加了对沙漠植物群落水可用性的了解。模拟结果表明，热水蒸气对沙漠土壤包气带的水土平衡有很大贡献。这项研究提供了一种描述干旱环境中土壤-水运动过程的替代方法，它增加了对沙漠植物群落水可用性的了解。模拟结果表明，热水蒸气对沙漠土壤包气带的水土平衡有很大贡献。这项研究提供了一种描述干旱环境中土壤-水运动过程的替代方法，它增加了对沙漠植物群落水可用性的了解。