Document Type : Research Paper
Authors
1
Faculty of Water and Environmental Engineering, Shahid Chamran University of Ahvaz
2
Associate professor in Irrigation & Drainage Eng. Dept. of Irrigation & Reclamation Eng. University of Tehran
3
Shahid Chamran University of Ahvaz
Abstract
In order to compare of WinSRFR and SIRMOD software in simulating furrow irrigation performance, a field experiment was carried out in the Jayedar Plain. Five different furrow irrigation methods including conventional furrow irrigation (CFI), surge irrigation with on/off cycle ratios of 1 and 0.5 (SFI1-1 and SFI1-2, respectively), fixed alternate irrigation (FFI) and variable alternate irrigation (AFI) were investigated. A total of 15 irrigation evaluations were performed at the initial, middle, and end of the growing season by measuring inflow rate, cutoff time, outflow rate, infiltration and advance time. The length and spacing of experimental furrows were 120 and 0.75 m and the inflow and cutoff times at the initial (3rd irrigation), middle (6th irrigation), and end (9th irrigation) were 0.28 L/s and 240 min, 0.42 L/s and 360 min, 0.35 L/s and 300 min, respectively. The WinSRFR 3.1 and SIRMOD software were calibrated, assessed, and compared using field measurements based on the zero-inertia model. WinSRFR and SIRMOD softwares demonstrated a strong correlation between the measured and simulated values of runoff, infiltration and advance time (coefficient of determination of (0.9984, 0.9976), (0.9908, 0.9932 ) and (0.9449, 0.9331), respectively. The relative error values of WinSRFR and SIRMOD Software in estimating runoff, infiltration and advance time were (2.96, 3.15), (3.03, 3.30), (2.09, 2.46) respectively. Both software overestimates the runoff (λ=1.0296 in WinSRFR and λ= 1.0315 in SIRMOD) and the advance time (λ=1.0209 in WinSRFR and λ= 1.0246 in SIRMOD). The WinSRFR software underestimates infiltration (λ=0.9697) but SIRMOD software overestimates infiltration (λ=1.0333). The results of this study show that AFI is a more suitable method for maize irrigation in the study area. The WinSRFR software has an advantage over the SIRMOD software in simulating furrow irrigation performance due to its higher ability and the use of a wide range of input parameters.
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