Optimization of Multipurpose Reservoir Systems Operation using Cellular Automata

This study deals with optimal operation of multipurpose reservoir systems, functioning for water supply to consumptive agricultural demands, hydropower generation and minimum environmental flow purposes, using cellular automata (CA). Discrete time instances (beginning of monthly time periods) are taken as cells and storage volumes at these instances are considered as the states of the cells. The CA updating rule is derived by optimization of local objective functions analytically in presence of nonlinear hydropower equations. Additionally, the sub-problem of optimal water allocation among different downstream users is solved using Lagrange multipliers technique. The proposed method was used to solve the nonlinear, non-convex operation optimization of Balarud reservoir and its hydropower plant as a real case study, and its performance was compared with the ones of gradient-based optimization methods and Genetic algorithm for periods of 5, 20 and 44 years. The results showed that the proposed cellular automata-based optimization model was able to find solutions with acceptable quality from the optimality perspective while rendering considerable reduction in the required computational load.