冻融条件下封闭体系中土壤水分运移规律模拟研究

Research on Mechanism of Soil Moisture Migration under Freezing and Thawing Condition

中国北方大面积土壤经历冬冻春融的冻融循环,这种循环引起了土壤中水分的运移,在室内模拟大自然冻融条件下,分析了均质饱和土壤在不同冻融时间和土壤深度的水分含量.实验证明封闭体系中土壤水分存在明显的“两段式”的水分运移规律,即冻结时土壤中的水分向表面冻层迁移;融化时,由于地表蒸发,土壤中的水分又向地表强烈迁移.

There is a cycle of freezing in winter and thawing in spring in north China soil, and this cycle causes migration of soil moisture. Based on the simulated freeze-thaw experiment, research is taken on mechanism of soil moisture migration in the condition of freezing and thawing. It demonstrates that there is an obvious ＂two-phase＂ migration mechanism： in the freezing process, moisture in the soil moves up to the freezing layer; and in the thaw process, this migration is intensified due to the surface evaporation.