Stable expression and control parameters in the numerical simulation of unsaturated flow

Abstract The Richards’ equation describes the flow phenomenon in unsaturated porous media and is essential to hydrology environmental science. This study evaluated numerical stability of two different forms equation. Sensitivity analyses were performed investigate control parameters results show that h -form has better applicability for calculating variable saturation flows than θ For equation, hydraulic conductivity soil low-suction range specific moisture capacity high-suction primarily influenced solution. In addition, sensitivity indicated saturated conductivity, initial condition, air-entry pressure have a higher simulation water content, rainfall intensity, decline rate conductivity. Moreover, their correctness needs be guaranteed first simulations. research findings can provide helpful reference improving reliability simulations flows.