SIRMOD and WinSRFR model simulation comparisons for furrow irrigation in a sugarcane field at Kasinthula Cane Growers Scheme, Malawi

Abstract

Models play a key role towards understanding real-life processes in various fields including surface irrigation. A better understanding of the performance of a particular model in simulating the processes in question is of prime importance. Against this background, simulation capabilities of the surface irrigation simulation, evaluation and design (SIRMOD) and WinSRFR models were compared through field studies conducted at Kasinthula Cane Growers Scheme (KCGS) in Malawi. The objectives of the study were to assess performance of each model in simulating water application and distribution efficiencies, and conduct a comparison in the resulting efficiencies and user-friendliness of each model. The study was conducted in sugarcane field furrows using volume balance method. Each of the two models estimated irrigation application efficiency, distribution efficiency, and deep percolation values that were very close to 51%, 79% and 49%, respectively, implying that the two were representative of each other. Both models showed the need for improving the current operation variables at KCGS to achieve optimal performance. It was further established that the simulation procedure in SIRMOD was more tedious than the one employed in WinSRFR. Furthermore, WinSRFR had a platform for conducting sensitivity analyses while SIRMOD did not. However, SIRMOD simulations had lower RMSE values for advance and recession than WinSRFR implying that SIRMOD model more accurately simulated these parameters than WinSRFR. The study also established that WinSRFR was a more appropriate model for practical application by irrigation frontline staff and/or farmers because it is more user-friendly than SIRMOD. The study concluded that SIRMOD's simulation accuracy presented it as a better research model than WINSRFR hence it would be ideal for calibrating and validating other surface irrigation models.