Risk analysis for the downstream control section in the real-time flood control operation of a reservoir

Abstract

Many uncertainty factors are associated with the joint operation of a reservoir and its downstream river, which create risks in flood control decisions. Therefore, this paper proposes an analytical method for the estimation of the uncertainties and their risks in real-time flood control decisions. Three uncertainty factors, including reservoir discharge errors, forecasting errors of lateral inflows and river food routing errors are proposed and modeled as stochastic processes, and their internal transforming formulas are derived based on the theory of routing before combination. The definition and calculation formulas for the risks of each moment and the integrated risk of the entire flood process at the downstream flood control section are proposed by an analytical approach based on the combination theory of stochastic processes. The Dahuofang reservoir in northern China is selected as the study case. The results indicate that the risk of the flood peak is higher than that of other moments under the same controlled flood discharge and that the risk that arises from the uncertainties of the reservoir discharge and lateral inflow is decreased by the river storage function. Compared with the Monte Carlo method, the proposed method is effective and efficient for performing risk analysis of the downstream control section in the real-time flood control operation of a reservoir. The risk analysis results could provide important information regarding flood risks for the operators to implement flood control arrangements.

Real‐Time Optimal Flood Control Decision Making and Risk Propagation Under Multiple Uncertainties

“…In previous studies, risk assessment has been conducted using fixed operation rules without optimization (Chen et al, 2015(Chen et al, , 2017Li et al, 2010;Yan et al, 2014). This study is distinct from all previous studies in that we explicitly incorporate flood forecast uncertainty into the optimization process.…”

“…However, gaps still exist between theory and application, and more efforts should be directed toward incorporating this type of forecast into water resources operations (Cloke & Pappenberger, 2009). Second, a number of risk analysis methods for flood control operation have been developed in recent years (Chen et al, 2015(Chen et al, , 2017Li et al, 2010;Tung et al, 2006;Yan et al, 2014). These methods can be used to calculate operation risks and evaluate the effect of flood forecast uncertainty on reservoir operation.…”

Benefit and Risk Balance Optimization for Stochastic Hydropower Scheduling

“…One of the most intractable difficulties is attributed to the uncertain and difficultly predictable inflow both in long-and short-term optimization (Chen et al 2015;Debnath et al 2015;Fan et al 2015). Zhao et al (2011) explored the effect of streamflow forecast uncertainty on real-time reservoir operation, and concluded that forecast uncertainty exerts significant effects.…”

Risk Analysis for Reservoir Real-Time Optimal Operation Using the Scenario Tree-Based Stochastic Optimization Method

“…We proposed a risk analysis method for reservoir real-time flood control operation by deriving the relationship between reservoir water levels and inflow forecast errors [24]. In addition, we also formulated an analytical method to calculate the risk of joint operation of a reservoir and its downstream river [25]. Generally, existing risk analysis methods can be divided into (1) direct integration method; (2) stochastic differential equation method; (3) Monte Carlo simulation; (4) structural reliability analysis method; and (5) fuzzy-sets based method.…”