LAUSR

Abstract An explicit finite-difference routine was developed to simulate the three-dimensional water movement from a trickle irrigation source by direct numerical integration of the Richards equation. Validation of the code was performed, on the one hand, by comparison with existing analytical solutions, and, on the other hand, with the HYDRUS 2D/3D software package to check different conditions further than assumed analytical simplifications. In the simulations performed, the routine showed an accurate and stable behavior. Additionally, it is flexible to define different boundary conditions. Furthermore, some specific studies performed with this routine are presented to illustrate the applications of this tool. It is shown that the code is able to reproduce water infiltration features such as redistribution, unsteady surface puddle area, and time-dependent overpressure around a buried emitter, which are phenomena of interest that are difficult to simulate with other software.