Multi-objective reservoir operation under emergency condition: Abbaspour reservoir case study with non-functional spillways

Abstract

The main objective of this study is to present a simulation-optimization approach methodology for short-term operation of multi-objective reservoirs during emergency conditions where risk of flooding and overflow from damaged spillways is significant. The paper considers flood risk management through enhancing dam safety as well as long-term objectives of the reservoir for hydropower generation and irrigation water supply simultaneously. In particular, real-time operation of Abbaspour reservoir during an emergency condition is considered where all flood discharging facilities are out of order for repairing the damaged parts. The proposed methodology combines a short-term and a long-term operation strategies to minimize risk of overflow for any possible incoming floods while preserving the long-term objectives of the reservoir. An efficient daily flow forecasting scheme provides the inflow data for the short-term (daily) operation strategy in a deterministic environment which follows the long-term operation policy. A multi-objective stochastic dynamic programming model addresses the long-term operation policy by solving the weekly operation model. The outcomes of the model application to the case study have illustrated its capabilities in developing a compromise between the risk of dam overflow and its long-term objectives.