Field Evaluation and Analysis of Furrow Irrigation by WinSRFR and SIRMOD Models

Shortage and water crisis have made it essential to improve management and consequently to increase the efficiency of irrigation systems. Since a large percentage of agricultural lands in Iran are irrigated by furrow irrigation, research on this method application is required. In this study, the simulation accuracy of WinSRFR and SIRMOD models were compared and analyzed with the data taken from the farm of Agricultural Faculty, Razi University, Kermanshah, Iran, where the field experiments were also performed. The farm soil had clay loam texture with bulk density of 1.18 g/cm3 under furrow irrigation. The length, depth, slope, and flowrate of the open-ended furrow under continuous flow were 25 m, 65 cm, 0.007 m/m and 4 l/s respectively. The results showed that the percentage of average prediction error of advance time in the WinSRFR model was 7 percent less than the SIRMOD model. The value of λ in simulation of WinSRFR and SIRMOD models was 0.82 and 0.68 respectively, which estimated the error rate of 18 and 32 percent, respectively. In estimating the average infiltrated depth, the WinSRFR and SIRMOD models estimated the average infiltrated water depth with λ = 0.97 and λ = 1.11, respectively, showing that the WinSRFR model has carried out the simulation of application efficiency with a three-percent error and with higher accuracy than the SIRMOD model. The results showed that WinSRFR model is more applicable and higher accuracy than the SIRMOD model.