Numerical simulation of water–heat coupled movements in seasonal frozen soil

In view of the insufficiencies of existing research into soil water and heat movements in seasonally frozen soil regions, water–heat coupled movements in seasonally frozen soil were studied by using a numerical simulation method. On the basis of viscous flow theory for liquid water in porous media and the heat balance principle, one-dimensional seasonal frozen soil water–heat coupled movements were modeled. A finite difference method was then performed to give the fully implicit finite difference form of the model. Finally the water status and the heat status of the seasonally frozen soil in the study area on November 3 2008 were simulated and tested. The results indicated that the simulated values of moisture and temperature for seasonally frozen soil had the same trends as the measured values, and the average relative errors of the soil temperature and moisture simulation were 9.67% and 9.54% respectively, which are both less than 10%. Thus, the one-dimensional seasonally frozen soil water–heat coupled movements model constructed in this paper and the numerical computation method are rational and reliable.