Optimization of ecological reservoir operation rules for a northern river in China: Balancing ecological and socio-economic water use

Abstract

With the conspicuous contradiction between water use inside and outside rivers, ecological reservoir operation has become a feasible approach to coordinate the relationship between socio-economic water use and ecological water use in rivers. However, ecological water demand in rivers remains difficult to be satisfied in areas facing serious water shortages, resulting in an imbalance between ecological and socio-economic water use. To satisfy the instream ecological water demands in water shortage areas, efforts were made on seeking an optimal reservoir operation scheme to balance the water supply for ecology and socio-economy. This study applied the index of guarantee rate of ecological water (GREW) to ecological river management, improved the previous reservoir operation rules, and constructed an optimization model of ecological reservoir operation rules based on dual-control management indexes. The Dagu River in Qingdao City, China, was selected as a study area to apply this model. The results showed that both the recommended scheme and the scheme without considering ecology could meet the socio-economic water demands, but the satisfaction degree of ecological water demand of the recommended scheme was significantly higher than that of the scheme without considering ecology. The scheme without considering ecology cannot ensure the ecological water demand in the Dagu River, especially for the non-flood season. Comparisons between the recommended scheme and the operation results without considering ecology demonstrated that the optimization model of ecological reservoir operation rules could effectively balance the ecological and socio-economic water use. In conclusion, the optimization model of reservoir operation rules with GREW can solve the problem of competitive water use inside and outside rivers, providing an important scientific basis for water resources management.