Application of Automatic Control Systems to Reduce both Seepage and Operational Losses in Main Earthen Irrigation Canals

Most common Losses in the agricultural water conveyance, distribution, and delivery systems are basically divided into two groups of losses due to seepage, and inappropriate operation of water level regulators and offtake structures. This study aims to examine the potential of automatic control systems in terms of simultaneously reducing seepage (through wetted perimeter) and operational losses. To achieve this goal, the seepage flow through the earth canal in the Moghan main irrigation canal as a case study was simulated via SEEP/W model. For this purpose, the obtained model was calibrated in accordance with the ponding method using the relevant measurement results. The sensitivity analysis on hydraulic conductivity was then performed to investigate Possibility of changing the behavior of soil hydraulic in the long canal could be realized. The HEC-RAS hydrodynamic model was used for the hydraulic flow simulation of the main canal. Then the ability of the designed centralized MPC system to realize the capabilities of this system in different possible situations and the primary goal of this research was tested with and without implementing the different operational strategy. The obtained results showed that the seepage loss could be reduced by at most 9.93%. However, the operational performance of the canal in terms of water delivery sufficiency to the offtake structures proved to be far-fetched and unacceptable. To improve the controller performance the inline storage operational strategy is coupled with the designed MPC system. According to the results obtained in the present study, implementing an automatic control system equipped with the inline storage strategy can simultaneously reduce both operational and seepage losses by 40% and 7.14% respectively. Other advantages of using an automatic control system combined with the inline storage strategy are guaranteed operation via maintaining suitable water delivery adequacy at the entire off-takes along the irrigation canal, and providing the required hydraulic conditions for controlling erosion.

Application of Automatic Control Systems to Reduce both Seepage and Operational Losses in Main Earthen Irrigation Canals Keywords:

Automation , Conveyance and Distribution Losses , Seepage Modeling , Operational of Main Canal