Application of Harmony Search Algorithm in Optimization of the Dez Dam Reservoir Operation for Long Period

Operation of reservoirs is influenced by lots of goals and generally many of these objectives are inconsistent with each other. The inflows of reservoir and storage volumes are uncertain, which lead to increase the complexity of the operation of the reservoirs. Utilization of optimization methods to determine the operational policy of the reservoirs is an important issue in the planning and management of water resources. Heuristic techniques have been developed as a tool in the optimization of complex systems. In this study, in order to evaluate the ability of the HSA in solving the problem of reservoir operation, and also to present the algorithm's efficiency in solving the problems with a large number of decision variables, optimization of the Dez dam reservoir operation is considered for a long time period (40 years). The goal is supplying the agricultural water demand of downstream. The global optimum value of the objective function was calculated 10.55 by application of the Lingo software and 19.78 by use of the HAS algorithm. The results of HSA were compared with HBMO and ACO algorithms and it was revealed that the HSA could present a better solution than HBMO and ACO algorithms. So, the use of this algorithm for optimal operation of reservoirs with more complex objective function and a greater number of reservoirs, could be recommended.