Performance Assessment of two Applied Algorithm Controls in the West Main Canal of Dez Irrigation Network

Automating the irrigation networks is one of the new approaches for making a proper water
management decision to improve the efficiency of these systems. In the present study, two robust
control systems of the Local Upstream PI Feedback Control with Filters and Centralized Distant
Downstream PI Feedback Control with Filters and Decouplers were designed and applied for the west
main canal of Dez irrigation network. The control algorithms programmed in MATLAB m-files and
connected to the SOBEK Canal Flow module through the SOBEK Real Time Control module. To
evaluate the efficiency of the control algorithms, the performance criteria of the Maximum Absolute
Error, Integral Absolute Error and Steady State Error were considered during the simulations of one
month with regard to the real off takes schedule with the highest variations within the cropping season.
The results indicated that the applied control algorithms 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. It was also concluded that the centralized control
system has more efficiency compared to local control system which provides flexible, demand
oriented and accurate operation procedure. Considering that local upstream controller may be
considered as an option, either as the main control system or as the backup system for the canal system
automation.