Risk-based Analysis of the Hydrological Uncertainties for Flood Management Strategies

Abstract: Designing a hydraulic structure with high capacity can impose additional costs on the project. Therefore, the importance of accurate design and proper selection of design parameters, optimal determination of flood return period and proper capacity of the flow channel are some of the topics that should been considered. Risk-based flow hydrograph estimation allows designers to take into account the uncertainties of the decision process and increase the level of reliability of hydraulic structures. In this research, hydrological uncertainties have been formulated based on probabilities to estimate the hydrograph of the dam reservoir output. To achieve this goal, time series data of maximum annual instantaneous flow for a period of 45 years were collected and analyzed. To achieve this goal, the genetic algorithm optimization method was used to calculate the best response and optimum return period. The results showed that the 40-year return period is a suitable option due to the hydrological uncertainty. Flow routing showed that the peak of the output hydrograph in the reservoir with a volume of more than 45 million cubic meters (MCM) will create a difference of about 13 m3/s.