土壤冻结过程中潜水蒸发规律的模拟研究

Simulation on phreatic evaporation during soil freezing

应用土壤冻结过程中水热耦合迁移模型模拟了内蒙河套灌区１９９０～１９９１土壤冻结期潜水蒸发过程，模拟值与实测值吻合较好．在此基础上，对不同负积温、不同潜水埋深条件下的潜水蒸发过程进行了模拟，并分析了埋深、负积温对冻结期潜水．蒸发总量的影响，提出了冻结期潜水蒸发折算系数的概念．潜水蒸发折算系数与负积温无关，有助于对土壤冻结期潜水蒸发规律的分析和应用．

As an application of the model of simultaneous moisture and heat transfer during soil freezing,the process of phreatic evaporation during the freezing period from November 1990 to March 1991 in Hetao Irrigation Area,Inner Mongolia Municipality is simulated.The simulated values of soil water storage and phreatic evaporation agreed well with the observed data.Moreover,phreatic evaporation under different accumulated negative temperature and water table depth is simulated to analyze their effects on phreatic evaporation.Based on the analysis,the concept of converted coefficient of phreatic evaporation during the freezing period is proposed.The converted coefficient of phreatic evaporation is not related to accumulated negative temperature,and thus will make contribution to the analysis and application of the patterns about phreatic evaporation during soil freezing.