Reservoir Hedging Approach in Optimal Operation of Water Resources Systems of Doiraj Dam Reservoir Using MOICA Algorithm

In this research, the simulation and optimization models are integrated to apply the reservoir hedging policy. Simulation of the studied basin was executed using the WEAP model to operate the Doiraj Dam reservoir located on the Doiraj River. In addition, the multi-objective MOICA model was utilized to optimize the system, in which the first objective function (maximizing the percentage of supplying demands), and the second one (minimizing the violation of allowable capacities of the reservoir during the operation period) were considered. In this regard, the operation modeling from the reservoir was carried out based on the current condition for a 720-month period (October 1960 to September 2019). Finally, by defining the optimization scenario and applying the reservoir hedging policy, the operation optimization of the reservoir was done and the results were compared with the reference scenario results. In this study, by considering 24 decision variables including 12 hedging level variables and 12 hedging coefficient variables, the optimal answers were achieved after 1000 iterations. The results showed that the violation of the allowable capacities did not occurred in any periods of the optimization scenario, while in the reference scenario the reservoir level reached the dead level in sequent months with more water shortage which might lead to the lack of water supply in such months and serious damages to the system. Due to the application of hedging policy in the optimization scenario, the percentage of supplying the demands in the critical months is increased between 20 to 35% as compared to the reference scenario, which indicates a significant reduction in the failure rate in such months.