Performance Assessment of Decentralized Automatic Control System for Applying in Operation of a Main Irrigation Canal under Inflow Fluctuations

Improving agricultural water productivity is one of the important objectives in irrigation canal networks. Accordingly, localizing and implementation of the modern operational technologies is essential. In order to deal with operation of main irrigation canal under inflow fluctuations, in the present study, the application of decentralized automatic control system, as the first step towards the canal automation is investigated. The Inflow fluctuations happen due to water scarcity in those irrigation networks located in the southern part of the watersheds. To this end, a decentralized PI Controller is designed to be applied for operation of mathematical model of the of Roodasht main irrigation canal. The deigned controller was tested by two normal and harsh unpredictable inflow fluctuation scenarios. The results of the simulation are evaluated by the operational performance evolution indices. The results indicate that the canal operational condition under the normal inflow fluctuations is reasonably controlled by the designed PI system. But in the case of harsh inflow fluctuations, the PI controller is not capable to handle the condition and the middle and downstream canal reaches are suffering from inappropriate water taking. Therefore it can be concluded that, application of the modern centralized controller would be recommended as a reliable options for operation of the main canal.