application of hec-ras and mike-11 models for flow simulation in irrigation canals

hydraulic simulation of water flow in irrigation canals may reveal management shortcomings and help managers find solutions to them. hydraulic simulation models can be appropriate tools for understanding hydraulic behavior of irrigation systems. in the present study, the steady state hec-ras model was tested and compared with the mike 11 unsteady state model. a secondary irrigation canal in the doroodzan irrigation system in southwest iran was selected to test the models. the control structures in the system were radial gates and sluiced orifices. new discharge algorithms were obtained for the free flow radial gates using previously published measured laboratory and field data and applied to the hec-ras model. the two models were calibrated and validated using two sets of observed discharges, gate openings and water levels. statistical indicators were used to compare the models. results showed that the new algorithms can be useful and the hec-ras model, with fewer estimation errors, appropriate for the study of steady state flow in irrigation canals. results showed that pinion height in radial gates is an important factor for developing discharge algorithms.