冻融土壤水热迁移数值模型的建立及仿真分析

Numerical Emulation on Simultaneous Soil Moisture and Heat Transfer under Freezing and Thawing Conditions

根据土壤中能量和质量守衡、地表能量平衡及空气动力学理论建立了冻融条件下土壤水、热耦合迁移模型、反映负温下土壤温度与液态水含量关系的联系方程和地-气间水热交换模型，采用隐式有限差分线性化迭代方法求解模型。在此基础上，对冻结条件下太原盆地中部汾河冲洪积平原区土壤冻结规律及不同灌水定额下的水热动态进行了仿真分析，表明冬灌具有储水保墒作用。

Based on the theory of mass and energy conservation in soils, the principle of energy budget on soil surface, and the theory of aerodynamics, a model of coupled soil moisture and heat transfer in soil - atmosphere continuum during soil freezing and thawing is established. The model includes the model of soil water and heat transfer, the relationship between soil temperature and unfrozen water, and the model of water and heat exchange in interface between soil and atmosphere. The model resolved by the Newton-Naphson iterative technique is used to simulate the process of soil freezing and thawing, and water and heat regime under different winter irrigation quotas in alluvial and pluvial plain in the middle of Taiyuan basin. The results shows that winter irrigation is effective for water storage in soils.