Investigating the interaction between statistical indices for performance assessment of Hyrum Reservoir on Little Bear River in an optimization model

Population growth and socioeconomic changes in developing countries over the past few decades have created sever stress on the available water resources across the world, particularly in semiarid regions, such as Utah. Hence, the optimal management of water resources is imperative. This study aimed to explore opportunities to provide the optimal reservoir operation rules for the Hyrum Reservoir, located on the Little Bear River in Utah, considering the reliability and vulnerability as the objective functions. Solving the multi-objective (herein two-objective) problem contributed us to investigate the interaction between reliability and vulnerability in this project. Modified Firefly Algorithm (MFA) was implemented as the optimization tool and three different problems, namely (1) single objective problem with reliability as the objective function, (2) single objective problem with vulnerability as the objective function, and (3) multi-objective problem with reliability and vulnerability as the objective functions, were solved. The results demonstrate the trade-off between the two objectives in the multi-objective problem. It also manifest that considering a multi-objective problem provide solutions whose the reliability and vulnerability values are within the upper and lower ranges calculated in the single objective problems.