Multi-objective optimization of water scheduling in irrigation canal network using NSGA-II

The objective of distribution and delivery of water canal scheduling in irrigation canal networks is timely and adequate delivery of water with minimum operational stages of the head gate of supply canal in the presence of canal capacity and irrigation rotation period constraints. In this paper, two objective functions, namely, the number of gate changes and the mean discharge for two networks, were minimized by the Genetic and NSGA-II algorithms. The results showed that minimizing these two objective functions at the same time leads to fewer gate changes compared to the only mean canal discharge objective function in both algorithms. It means the mean discharge objective function cannot minimize the number of operational stages alone. Also the optimization by NSGA-II algorithm did not make a significant difference in the results in comparison with the genetic algorithm for both objective functions. However, in NSGA-II algorithm, it is not necessary to determine the weight of each of the objective functions.