SPRINKMOD - pressure and discharge simulation model for pressurized irrigation systems. 2. Sensitivity to lateral hydraulic parameters and leakage

A computer model, SPRINKMOD, was tested with field data collected from a si mple sprinkler irrigation system in operation. The original data for latera ls and the amount and way leakage is considered were modified to evaluate t he model sensitivity. The model predicted the pump station flow rate within 2% and the pump station pressure head within 5% with the original data col lected. For this irrigation system, no practical effect was observed in the system operating point by changing the lateral pipe characteristics, later al leakage amount and distribution, lateral pipe roughness and lateral loca l loss coefficient for flow past a riser outlet. The amount of leakage had more effect on the model simulation of pressure heads than the way leakage was considered, localized or distributed along the laterals. The use of a v ariable local loss coefficient, K-r, along the 350-m hand-move laterals had a negligible effect on both system operating point and distribution of pre ssure heads along the laterals.