Modern Operation of Main Irrigation Canals Suffering from Water Scarcity Based on an Economic Perspective

The main objective of this study is to determine the optimal distribution of water between upstream and downstream users in a main irrigation canal with a limited supply of water in order to maximize the net revenue derived from existing farming activities. To this end, an economic positive mathematic programming (PMP) model is employed to determine the economic value of the water for each delivery point along the main canal in which there is agricultural activity. This information is added to a model that accounts for the operational aspects of a realistic, large irrigated district in the center of Iran, which is used by a model predictive controller to prioritize the reaches in the main canal according to their potential profit in economic terms. The results show the satisfactory operation of the canal reaches, such that the water levels in the reaches with high economic water value are kept closer to the operational target levels. Accordingly, the water deficit is proportionally divided along the main canals to maximize economic profits from the irrigated district.