A. Montazar - Department of Irrigation and Drainage Engineering, Campus of Aburaihan, University of Tehran, Islamic Republic of Iran.
S. Isapoor - Yekom Consolation Engineers, Tehran, Islamic Republic of Iran.

In the face of limited water resources, better utilization and operation of irrigation networks is essential. Use of control systems is considered as one of the most assured ways to achieve the aim. In the course of the present study, two centralized controllers are applied to the west canal of Aghili irrigation district in I. R. Iran. The proposed control algorithms consist of a distant Downstream PI Feedback control (DPIF), and a distant Downstream PI Feedback along with Feedforward control (DPIFF). In the controllers, each water-level regulator is adjusted as based on water levels in all the pools of the canal. The test case canal and flow scenarios are simulated using SOBEK. The controllers are evaluated using the simulation results. The results indicated that both of the proposed controllers possess the considerable needed potential to closely match the discharge (at the cross regulators) with those ordered by water users while properly maintaining the water level throughout the length of the canals of the irrigation system. It is apparent that the DPIFF controller is more effective than DPIF controller in providing a desirable performance. Use of these algorithms makes demand oriented water distribution as well as a better performance of the system possible. The DPIFF controller as the main control system accompanied by a local controller as a backup system can be recommended to present an efficient robust control system for the canal.

Aghili irrigation system, Centralized control, Control systems, Downstream control, PI controller