SURCOS: A software tool to simulate irrigation and fertigation in isolated furrows and furrow networks

•We present SURCOS, a software tool to simulate fertigation in furrow networks.•It solves both unsteady surface flows with solute dispersion and infiltration.•The numerical error in water and solute mass is limited to the machine accuracy.•The model relies on a verified and validated, robust and accurate numerical method.•The program is fast, easy and free.

A software tool useful for the numerical computation of surface irrigation and fertigation in furrows and furrow networks was developed. The model solves the complete one-dimensional St-Venant equations together with the transport equation of a passive solute. The flow equations and the solute advection are solved with a high resolution TVD explicit Eulerian scheme. The solute dispersion is solved with a centered implicit Eulerian scheme to avoid further restriction in the allowable time step. The computational speed of the model is high in isolated furrows. In cases of large furrow networks over extended irrigation times the model is slower but affordable computational speed is achieved. The computational model has been designed to be robust, intuitive and able to supply useful visual results. Both the executable and the source code, as well as the examples presented can be downloaded, edited and distributed under a BSD type license.