Study on Soil Water Movement With Changeable Groundwater Level During Soil Freezing and Thawing

A model of simulating the moisture and heat transfer under shallow groundwater level during soil freezing and thawing was established. The hybrid Richards equation was used to study saturatedunsaturated water movement of frozen soils. The comparison between simulated and observed results showed that the model was reliable. The relationship between initial groundwater level and the maximum drop of groundwater table can be expressed with the inverseLogistic curve. Moreover, suitable groundwater level before soil freezing for the studying case is about 1.5 m to 2.0 m, which can be used in irrigation schedule in Hetao Irrigation Area.