Multi-reservoir joint operating rule in inter-basin water transfer-supply project

The joint operation of inter-basin water transfer-supply (IBWTS) project can be more complex when there is joint water demand in multi-reservoir system and multi-importing reservoirs simultaneously transferring water from exporting reservoir. In this study, a joint operating rule is proposed for the purpose of solving such complex operation problem. This rule is composed of a set of sub-rules, including hedging rule curves of virtual aggregation reservoir (i.e. equivalent reservoir) and other individual reservoirs, water-transfer rule curves of each individual reservoir, as well as some of important assisted rules. These assisted rules refer to allocation models for water transfer-supply. In the proposed rule, an equivalent reservoir is established to determine under what condition the water supply should be reduced and specify the total supplied water for joint water demand (i.e. aggregation method). Allocation models are developed to distribute the total transferred water into each importing reservoir and determine the water releases for joint water demand by each member reservoir of the aggregation system (i.e. decomposition method). And these models are integrated with a set of influence factors such as hydrologic characteristics, reservoir storage or vacant storage, regulating ability, water-supply pressure, and so on. The aggregation of multi-reservoirs and the disaggregation of water quantities are taken into a whole consideration to reduce the complexity in reallocation of water target storage or water release. Finally, the proposed rule is applied to the North-line IBWTS Project in Liaoning Province, China. The results indicate that the proposed rule can take full advantage of hydrologic compensation in basins and capacity compensation in reservoirs. Thus it can improve the utilization efficiency of water resources in system.