A Trade-Off Analysis of Adaptive and Non-Adaptive Future Optimized Rule Curves Based on Simulation Algorithm

This study aims to investigate the performance of Zarrineh Rud reservoir by implementing strategies for adaptation to climate change. Using sequent peak algorithm (SPA), the rule curve were simulated. Then, the optimal rule curve was procured through GA-SPA, aiming to minimize the water shortage. The future data were downscaled using SDSM based on CanEsm2 model and under RCP2.6 and RCP8.5. Finally, in view of environmental demand, reservoir performance indices were calculated for both non-adaptive and adaptive policies during all future periods (2020–2076). Results showed simulation with the static hedging rules managed to significantly reduce the average vulnerability index (by 60%) compared to no hedging, while the dynamic hedging rules outperformed static hedging rules only by 9%. Therefore, considering the insignificant improvement in reservoir performance using dynamic rules and their complexity, static hedging rules are recommended as the better option for adaptation during climate change.

Development and Evaluation of the Hydropower Reservoir Rule Curve for a Sustainable Water Supply

The Seoul metropolitan area in the Han River basin is searching for sustainable water supply options after recently experiencing an extreme drought. Building a new reservoir is a common way to alleviate water shortage, but this comes at a great environmental cost. The South Korean government granted permission to add on a water supply function for the Hwacheon Reservoir, the largest hydropower reservoir in Korea, for the first time in the history. This study develops a new rule curve for the Hwacheon Reservoir to supply water and generate energy at the same time, considering the status of other reservoirs in the Han River basin. The simulation model uses two scenarios, with scenario 1 simulating historic operation and scenario 2 applying the deficit supply method. The new rule curve was formulated based on the results from scenario 2. Time-based and volumetric reliability increased by 33% and 4%, respectively, and resiliency more than doubled compared to the historic reservoir operation. This is the first case study in South Korea that demonstrates how to successfully integrate a water supply function into an existing hydropower reservoir. This study can be applied and extended to other river basins in an attempt to alleviate water shortages by adding new functions to existing reservoirs.

Verification of FPA and PSO algorithms for rule curve extraction and optimization of single- and multi-reservoir systems' operations considering their specific purposes

The optimal operation of reservoirs is known as a complex issue in water resources management, which requires consideration of numerous variables (such as downstream water demand and power generation). For this optimization, researchers have used evolutionary and meta-heuristic algorithms, which are generally inspired by nature. These algorithms have been developed to achieve optimal/near-optimal solutions by a smaller number of function evaluations with less calculation time. In this research, the flower pollination algorithm (FPA) was used to optimize: (1) Aidoghmoush single-reservoir system operation for agricultural water supply, (2) Bazoft single-reservoir system operation for hydropower generation, (3) multi-reservoir system operation of Karun 5, Karun 4, and Bazoft, and (4) Bazoft single-reservoir system for rule curve extraction. To demonstrate the effectiveness of the FPA, it was first applied to solve the mathematical test functions, and then used to determine optimal operations of the reservoir systems with the purposes of downstream water supply and hydropower generation. In addition, the FPA was compared with the particle swarm optimization (PSO) algorithm and the non-linear programming (NLP) method. The results for the Aidoghmoush single-reservoir system showed that the best FPA solution was similar to the NLP solution, while the best PSO solution was about 0.2% different from the NLP solution. The best values of the objective function of the PSO were approximately 3.5 times, 28%, and 43% worse than those of the FPA for the Bazoft single-reservoir system for hydropower generation, the multi-reservoir system, and the Bazoft single-reservoir system for rule curve extraction, respectively. The FPA outperformed the PSO in finding the optimal solutions. Overall, FPA is one of the new evolutionary algorithms, which is capable of determining better (closer to the ideal solution) objective functions, decreasing the calculation time, simplifying the problem, and providing better solutions for decision makers.

Optimization of Reservoir Operation using Linear Programming

The paper aims to derive the optimal releases monthly through linear programming for a single purpose reservoir. The releases from the reservoir are usually based upon the rule curves or operating policy adopted. The rule curve is the storage, indicating the water levels to be maintained in-order to satisfy the demand during the operation period. Linear programming (LP) is one of the global optimization techniques that have gained popularity as a means to attain reservoir operation. In the present study Linear Programming was used to develop an operation policy for Hemavathy Reservoir, Hassan District Karnataka, India. The decision variables were monthly reservoir releases for irrigation and initial storages in reservoir at beginning of the month. The constraint bound for the reservoir releases was reservoir storage capacity. The results derived by using Linear Programming shows that the downstream irrigation demands were satisfied and also considerable amount of water was conserved from reduced spills.

STUDY ON RULE CURVE DEVELOPMENT FOR HYDRO ELECTRIC POWER (HEP) DAM OPERATION. CASE STUDY: MURUM HEP DAM

An operation rule curve of a dam provides specific on the target elevation of thereservoir. This can vary throughout the year. This is an indication to the reservoir operator ofactivities to conduct for various situations involving reservoir and the hydrologic conditions.This rule curve shall apply to Murum dam solely for power generation purpose. Thedecisions on when and how much to release will impact the ability to pass a flood as well ashydropower capacity. The main objective of this research is to select the most suitablemethod and to develop the operation rule curves for Murum dam primarily for hydropowergeneration. A trial-and-error method has been selected for this study. Reservoir operationmodeling and simulation have been commenced using historical rainfall data, after runoffwas generated by rainfall runoff modellings. Three (3) simulations are conducted fordeveloping the operation rule curves. They are rule curve according to Sarawak EnergyBerhad’s requirement, ideal rule curve and mean rule curve. All three sets of rule curves aresuccessfully developed using turbine discharges of the dam as the parameters and to achievethe target firm energy generation of 635MW.

Rule curve for seasonal increasing of water concessions in reservoirs with low regularized discharges

ABSTRACT Regions with high hydrological variability are usually supplied by reservoirs that regularize discharges inter-annually, with low discharge of regularization, seasonally subject to large overflow and evaporation losses in their periods of high water levels. The Brazilian semiarid is one of such regions. This work looks at the possibility of using water that would be evaporated and/or spilled, in regions with such characteristics, to supply demands that would not be otherwise provided by the maximum legally allowed withdrawal discharge. The proposed method was applied to the operation of a large reservoir, located in the semiarid region of Brazil. Through simulation of the water budget and optimization, a rule curve was developed for reservoir operation for achieving the maximum exploitable reservoir withdrawal in rainy periods. The results show that it is possible to use the excess water in periods of large inflows with no damage to water supply during dry periods.