عنوان مقاله [English]
SIRMOD as one of the widely used softwares for simulation of furrow irrigation uses Saint- Venant equations to describe different phases of furrow irrigation and Kostiakov-Lewis infiltration model to predict the infiltrated water volume during irrigation. The method of determining the coefficients of the infiltration equation, simplified assumptions for infiltration equation and considering infiltration as a one-dimensional phenomenon cause some effective factors in the infiltration process to be neglected. Therefore, using a software such as HYDRUS that uses Richards equation as basic water movement equation and considers many effective factors in infiltration, can increase the accuracy of predicted infiltrated water volume and consequently simulation accuracy. In this research, after conducting field experiments and recording related data, all phases of furrow irrigation were predicted using the SIRMOD and the results were introduced to the HYDRUS-3D as initial and boundary conditions to determine the infiltrated water volume using the Richards equation. Finally, the simulated values from two models were compared with the experimental data. Results showed that the complete hydrodynamic model in SIRMOD had high ability in the prediction of all phases of the irrigation, especially in advance phase and the HYDRUS-3D model simulated the infiltrated water volume and outflow hydrograph more accurately than SIRMOD model. Comparison of results from the models and measured values showed that incorporation of the two softwares would increase the accuracy of simulated infiltration and run-off values. In addition, the important advantage of this method is simulating soil water distribution during all irrigation phases.