Numerical and Analytical Simulation of Wetting Front Advancing in Drip Irrigation

Achieving the full potential of drip irrigation requires optimizing its effective operational parameters. For a given soil، knowing the temporal evolution of the wetted volume can contribute to a proper determination of emitter spacing and duration of irrigation as a function of the root zones soil volume. To investigate the optimal drip management practices، numerical and analytical simulations are easy and inexpensive approaches. In this study، the physical properties of the soil for simulation of wetting front position in drip irrigation were determined. Then، in order to calculate Van Genuchten model parameters، soil water characteristic curve was determined by means of a pressure membrane apparatus. Also، for solving the Philip and Ben-Asher equations، some computer programs were provided using Mathematica 7. 0. The HYDRUS 2D was used for numerical simulations. Statistical comparisons of the simulated and observed radial distances from emitters were employed to evaluate the accuracy of the analytical and numerical models. Results showed that HYDRUS 2D output with relevant root mean square error of 3. 32572 and correlation coefficient of 0. 9607 had a better agreement with the observed wetting front data in comparison with other methods and، in general، it’s the best method for simulating of wetting front in drip irrigation.