Canopy effect caused by vapour transfer in covered freezing soils
Canopy effect caused by vapour transfer in covered freezing soils
复制标题
覆盖的冻土中水蒸气传输引起的冠层效应
DOI：
10.1680/jgeot.16.p.016
复制
发表时间：
2016-11-01
期刊：
影响因子：
5.8
通讯作者：
Sheng, D.
中科院分区：
文献类型：
--
作者：
Zhang, S.;Teng, J.;Sheng, D.
在本文中，树冠效应是指水分在不透水覆盖物下积累的现象。现场观测表明，在地下水位较深的相对干燥的土壤中可能会出现树冠效应，并可能导致紧邻不透水覆盖层下的土壤完全饱和。然而，基于现有的非饱和土壤热质传递理论的数值分析只能再现由不透水覆盖引起的少量水分积累，特别是在地下水位相对较深的情况下。为了解释野外观测到的冠层效应，本文提出了非饱和冻土中水分积累的一种新机制：非饱和冻土中的水蒸气传输被汽冰脱湿过程加速。提出了一种新的模拟湿热运动的方法，该方法考虑了水蒸气在蒸发、冷凝和脱湿过程中的相变。一个实验室设备..。
Canopy effect in this paper refers to the phenomenon whereby moisture accumulates underneath an impervious cover. Field observations reveal that the canopy effect can occur in relatively dry soils where the groundwater table is deep and can lead to full saturation of the soil immediately underneath the impervious cover. However, numerical analysis based on existing theories of heat and mass transfer in unsaturated soils can only reproduce a minor amount of moisture accumulation caused by an impervious cover, particularly when the groundwater table is relatively deep. In an attempt to explain the observed canopy effect in the field, this paper proposes a new mechanism of moisture accumulation in unsaturated freezing soils: vapour transfer in such a soil is accelerated by the process of vapour–ice desublimation. A new approach for modelling moisture and heat movements is proposed in which phase changes during the evaporation, condensation and desublimation of vapour flow are considered. A laboratory device ...