Automatic Control of Flows and Levels in an Irrigation Canal

Modernization of irrigation canals is becoming a strategic issue in many areas of the world with the purpose of improving the efficiency and the operational flexibility in water delivery. Apparently, small deviations in keeping flows at the desired scheduled values can lead to significant waste of water, which is particularly important in arid countries and dry periods. Automatic control systems are being considered as the alternative to increase the low performance of traditional manual operations. This paper describes the implementation of two control systems in the so-called Canal de Lodosa, one of the canals that convey irrigation water from the Ebro River in Spain. The systems are designed using classical proportional-integral and adaptive predictive control, respectively, which are two of the methodologies mostly used in process control in different industrial areas nowadays. This paper introduces the canal-control problem and the models to describe the dynamic behavior, including experimental identification. The designs of both control schemes are described, and field implementation results are presented and comparatively discussed in terms of performance, control efforts, and working load.