氚示踪剂在土壤包气层实验中的应用

The application of ~3H tracer in soil aerated zone tracing experiment

测定了土壤包气层中氚在天然条件和人工喷淋条件下的扩散系数，研究了氚示踪剂在黄土包气层中的迁移规律．实验结果表明，在华北地区黄土高原天然条件下，包气带中氚示踪剂以０．０３ｃｍ／ｄ速度迁移，纵向扩散系数Ｄｘ为０．１０ｃｍ２／ｄ；在２ｍ２实验坑中，以５ｍｍ／ｈ喷淋强度每天喷淋３ｈ的条件下，氚示踪剂以２．２７ｃｍ／ｄ的速度向下迁移， ＤＸ为７．７５ｃｍ２／ｄ。

Diffusivity of 3H was measured in soil aerated zone on both natural and artificial rainfall conditions, migration of 3H tracer was also studied in loess aerated zone at the same time. The results implied that the migration velocity of 3H tracer in aerated zone was 0.03cm/d on natural condition in loess plateau of Huabei Region, the vertical diffusivity Dx was 0.10cm2/d. In the experiment pit, the migration velocity was 2.27cm/d under an artificial condition of 5mm/h sprinkling intensity for 3 hours each day, the vertical diffusivity Dx was 7.75cm2/d.