In analyzing the seepage processes in unsaturated porous media

numerical instability may occur due to the difference between the adopted physical and numerical models under nearly saturated conditions. To resolve the issue and improve the numerical results

three methods are proposed and then implemented into the finite element code U-DYSAC2. Numerical simulations are compared with the experimental data available in the literature

showing that the problems related to numerical stability

convergence and accuracy can be induced by the high nonlinearity of soil water characteristics and hydraulic conductivity functions under nearly saturated conditions; and significant numerical discrepancies can appear in predicting the water content and matric suction of the porous media. Among the three proposed methods

modified Van Genuchten model (MVGM) method yields the best results in calculating the moisture content; while the Line method achieves best prediction for matric suction. Consequently

in analyzing the seepage processes in unsaturated porous media

it is crucial to introduce a proper analysis procedure such that reliable numerical results can be achieved