The essential problem for reservoir operation is how to deal with variability of inflow. The impacts of both climate change and human interferences on streamflow further complicate the issue of reservoir inflow variability. This paper presents a case study of a reservoir that has both natural inflow (NI) and controlled inflow (CI), and analyzes how CI, which can be a deterministic item, mitigates the effect of NI variability on reservoir operation. Through a case study of the Biliu River Reservoir in northeastern China, the following questions are addressed: (1) how will the combined NI and CI improve water supply reliability, and (2) can—and if so, how much—of the reservoir’s storage can be reduced without lowering water supply reliability with a certain level of CI? It is found that CI complements NI in terms of water supply reliability through a nonlinear relationship, as shown by an inverse S curve; the two turning points in the curve specify a range of CI with respect to the stochastic nature...

The construction of water transfer projects brings new challenges to water resources management, especially in water supply security with the use of multiple water sources. However, the operations of water diversion and water supply have been considered in separation in practice. In particular, there are few decision support systems (DSS) designed to tackle the challenges in emergency planning of water transfer operation. This paper describes a generic DSS which is designed for the operation of multiple water sources supply and complex water supply targets. Emergency management is incorporated in the DSS to provide more effective water supply under extreme conditions. Specifically, the emergency scheduling plans regenerate the water supply strategy of Biliuhe Reservoir and Yingnahe Reservoir, and then reduce the impact of severe drought year on Dalian. The scheduling results of the case study reveal that this DSS makes good use of mutual compensation functions among multiple water sources when it is applied to the water supply emergency management of Dalian in severe drought year. The results indicate this developed DSS can be easily generalized and further applied to similar cities in China and other countries in the world.

This study aims to present a joint operation framework for complex multiple reservoir systems to balance water supply between subsystems and between different stakeholders, and support decisions about water releases from the entire system and individual reservoirs effectively. The framework includes three steps: (1) aggregated virtual reservoirs and various subsystems are established to determine the water releases from the entire system; (2) the common water-supply strategy is identified to determine the water releases from individual reservoirs; and (3) the joint operation problem is solved with a multi-objective optimization algorithm and the results are analyzed using a Many-Objective Visual Analytics Tool (MOVAT). A case study of the DaHuoFang-GuanYinGe-ShenWo multi-reservoir system in northeastern China is used to demonstrate the framework. Results show that the establishment of aggregated virtual reservoirs and identification of a common water-supply strategy could make use of the temporal and spatial differences of runoff, exert the effects of underlying hydrological compensation between river basins, and reduce the complexity of the joint operation model for multiple reservoir systems effectively. The MOVAT provides an effective means of solving many-objective problems, which are generally of particular concern to the decision-maker in practice.