冻融期地下水位变化情况下土壤水分运动的初步研究

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

建立了地下水浅埋条件下土壤冻融期水热耦合迁移模型，并采用混合型Ｒｉｃｈａｒｄｓ方程对冻融过程中的土壤饱和—非饱和水分流动问题进行了初步研究。模拟结果与试验资料的对比表明所采用的模型是可靠的。根据模拟结果，冻结过程中潜水位最大降深与初始潜水埋深间的关系可用反Ｌｏｇｉｓｔｉｃ公式表示。对于内蒙古河套灌区，考虑融化期春小麦需水要求的土壤封冻前的适宜地下水位约为１．５ｍ～２．０ｍ。

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.