Investigation of the effect of operational errors on the performance uncertainty of irrigation networks in arranged delivery

Arranged delivery is recommended for higher irrigation management flexibility and water productivity in irrigation networks. For arranged delivery, the spatial and temporal variations of numerous requests increase the complexity of the operation and the probability of operational errors. The objective of this research is to consider the operational errors and analyze their impact on output uncertainty. To this end, in a canal, two options of increase and decrease in demand, and four scenarios of structural operational errors are studied. The structural operational error scenarios include one check structure, one check and one intake, two check structures, two checks, and one intake. In each scenario, random numbers for structural adjustment were generated using the Monte Carlo simulation method. The canal system, operational scenarios, and delivery options were simulated using the Irrigation Conveyance System Simulation (ICSS) model. The analyzed outputs are delivery discharge, adequacy, efficiency, stability, and depth control error. The uncertainty of outputs is calculated for the operational error range of 38 to 95 %. The uncertainty band of the flow delivery for the increasing scenario was between 38 to 95%, and 33 to 85% for the decreasing scenario. Therefore, increasing scenarios produce higher uncertainty, and require a more accurate operation. By increasing the number of structures that encounter operational error, the uncertainty of almost all outputs has increased. The highest increment of 12% was seen in the stability index for the increasing scenario and an 8% uncertainty band increase in the depth index for the decreasing scenario. For increasing scenarios, delivery discharge with an uncertainty band of 38 to 95% is the most sensitive parameter. For decreasing scenarios, the depth control parameter with an uncertainty band of 36 to 82% is more sensitive compared to delivery flow. Therefore, for increasing scenarios the delivery discharge, and for decreasing scenarios, the water depth are more important parameters to be controlled.