Optimization of Multiple Reservoirs Operation with Consideration to Sediment Evacuation

The paper develops a new methodology and RESOOSE model for optimizing operation of multiple reservoirs considering sediment evacuation for multiple objectives consisting of maximization of irrigation, hydropower, storage conservation and minimization of flood damages. The optimization and sediment evacuation modules of the model are based on Genetic Algorithm and Tsinghua equation respectively. According to the criteria developed for selection of reservoirs, three reservoirs on Indus River of Pakistan have been selected. The model has been calibrated and validated for Tarbela and Chashma Reservoirs. The calibrated model has been applied to Diamer Basha (proposed) and Tarbela Reservoirs. Eight scenarios comprising of combined and individual objectives were developed. The optimized results of different scenarios have been compared with existing rule curves. The optimization results reveal that objective function for hydropower, irrigation, and storage conservation benefits would be enhanced by 11, 13 and 84 % respectively while flood damages would reduce by 80 %. Similarly the optimized rule curves will increase the benefits up to 579, 960, 533 and 648 million US$ per year (on 2012 prices) for all the four components respectively. The maximum value of US$ 977 million per year has been found for the scenario 5 which gives equal priority weight to all the four sectors. The developed model can be applied to other two reservoirs (in series) for optimization of rule curves.