Computational evaluations of HYDRUS simulations of drip irrigation in 2D and 3D domains (i-Surface drippers)

•This is a two-part research, this part for subsurface drip, and the first part for surface drip.•We evaluated the effect of different domain geometries, element shapes, coordinate systems, emitter discharges, and soil textures on the accuracy and stability of the simulation.•The 3D simulations are more successful and reliable than the 2D simulations in terms of mass balance error.•For the 2D domains, the error is higher for finer textures, and for axisymmetric domains.•Flux-conductivity ratio should be