Abstract
In the present study, a distant downstream proportional integral (PI) feedback control with decouplers and a local upstream PI feedback control were applied to the West main canal of the Dez irrigation system in Iran. The model of the proposed canal was formulated in the SOBEK simulation package. The control system was programmed in MATLAB. To evaluate the control system potential, simulations were done for two months of the real offtake schedule. The performance criteria of the maximum absolute error (MAE), the integral of absolute magnitude of error (IAE), and the steady state error (StE) were determined for each pool of the canal. The results indicated that the applied controllers have considerable potential to closely match the discharge at the downstream check structures with those ordered by water users while maintaining the water level throughout the length of the canal. The performance indicator values showed that the distant downstream feedback (FB) control as a centralized control with decouplers is a satisfactory controller for the Dez main canal. Hence, operational water management in the canal may be improved if a centralized controller is used rather than individual local controllers. It is strongly recommended to implement the distant downstream FB control with decouplers as a control system in the proposed canal. Copyright ยฉ 2009 John Wiley & Sons, Ltd.