Validation of Surge Model Using Furrow Gradient and Flow Retardance

Introduction: Surface irrigation, our oldest method of applying water on to the cropped land, has withstood the test of time because of its many advantages. Over the years, minor changes have been made to improve the efficiency of surface irrigation system.

Aim: The present study was taken to validate the existing model with furrow gradient and flow retardance.

Principle: The experimental layout has been made to accommodate the variance such as the furrow gradients (0.3%, 0.6% and 0.1%), the modes of irrigation namely the continuous flow as control and the surge flow as the treatment. Surge irrigation is a relatively new technique whereby water to surface irrigated furrows is applied intermittently in a series of relatively short ON and OFF time periods of irrigation cycles.

Results: It is claimed that the ON-OFF cycling of the flow for specific time periods produces surges during the ON period and influences the soil intake during the OFF period when water soaks into the soil. The net result is a reduction in soil infiltration rates during subsequent surge ON periods and an increase in the rate of water front advance. The SURGEMODE model can only gives the net water front advance time that can be predicted for non-vegetated condition and a standard reference slope. However when the furrow is getting vegetated or when the slope gradients are changed, the water front advance predicted through the existing model cannot be predict accurately.

Conclusion: Hence, the study involved to validate the existing model with furrow gradient and flow retardance. The use of revalidated existing SURGEMODE model with the correction factor would be the exact suitable model for the local condition.