半干旱地区包气带浅部黄土中水分运移特征

水特征曲线测量、水分运移的现场观测以及用＾３Ｈ作为示踪剂的现场示踪试验被同时用于水分在包气带浅部黄土运移研究之中。研究结果表明，在半干旱地区的包气带黄土中，土壤浅部水的上下运动明显；降水的垂直入渗量甚小，最多约为降水量的１％；而且降水的垂直入渗量随深度增加而减小。研究证实，用经验公式的计算结果与实际测量值符事得比较好。

Moisture Movement Characteristics in Shallow Unsaturated Loess in Semi-arid Area

Three methods were used in this research. They are water retention curve measurement, field observation of moisture movement and field nuclide migration test used 3H as tracer. It is shown from the results that moisture in shallow unsaturated loess moved obviously down and up as well as was poor in the semi-arid area. The maximum infiltration amount of water was about 1% of precipitation. Moreover, the vertical infiltration amount of precipitation decreased with depth in unsaturated loess. It is validated from the research that the results calculated by the experiential equation were in keeping with the measured ones obtained from the field nuclide migration test very well.