Abstract
The hydropower system’s water-energy-ecosystem nexus (WEEN) has gained particular focus in the last years. The water-use trade-offs between hydropower and ecosystem maintenance are complex and variable for cascade hydropower systems, leading to challenges in water resources management and sustainable development of hydropower. To understand the trade-off in the WEEN of cascade hydropower systems and their changes, a WEEN model using the multi-objective optimization approach is developed in this study, including maximizing cascade power generation, minimizing reservoir water footprint, and minimizing amended annual proportional flow deviation. These optimization objectives characterize the nexus’s water, energy, and ecosystem sectors. And the Pareto non-inferiority solutions are obtained by the third edition of the Non-dominated Sorting Genetic Algorithm. Also, we novelly propose an evaluation index called the Multi-objective Trade-off Index (MTI), a quantitative method with clear physical meaning to explore the trade-offs as revealed between different objectives by the solutions. A case study of the Yalong River, China, has shown that: 1) the larger the incoming water is, the more beneficial to the power generation and ecological benefits of the hydropower system; and 2) the trade-off degrees of the water sector with respect to energy-ecosystem and energy sector with respect to water-ecosystem decreases when the hydrological condition changes from wet to dry, while the degree of ecosystem sector with respect to water-energy increases. In general, the proposed MTI that quantifies trade-offs in the WEEN of cascade hydropower systems is efficient and feasible. Meanwhile, the MTI is also generic and can be applied to other multi-objective optimization problems.
Highlights
The water-energy -ecosystem nexus (WEEN) is a focus of much research (Kuriqi et al, 2020; Vinca et al, 2021; Yadav et al, 2021)
We developed a WEEN model using the multi-objective optimization approach, including three objectives: maximizing cascade power generation, minimizing reservoir water footprint, and minimizing amended annual proportional flow deviation of the watershed outlet, and the Pareto non-inferiority solutions are obtained by the third edition of the Non-dominated Sorting Genetic Algorithm
The cascade power generation (CPG) and annual proportional flow deviation (AAPFD) vary greatly under different hydrological conditions, and both shows: wet year > normal year > dry year, which indicates that the larger the incoming water is, the more beneficial to the power generation and ecological benefits of the cascade hydropower system in the Yalong River
Summary
The water-energy -ecosystem nexus (WEEN) is a focus of much research (Kuriqi et al, 2020; Vinca et al, 2021; Yadav et al, 2021). Hydropower plants (HPs) use the kinetic and potential energy of water to generate clean energy (hydropower), Trade-Offs in the Water-Energy-Ecosystem Nexus and at the same time, reservoirs with regulating capacity provide water for downstream irrigation areas and towns; on the other hand, dams block rivers and affect the survival and reproduction of fish, which may cause enormous adverse impacts on the downstream river ecosystem (Suwal et al, 2020; Kuriqi et al, 2021) This means that there are significant water-use trade-offs between water, energy, and ecosystem sectors for hydropower systems (Zhang et al, 2018b), i.e., the benefit achieved by one objective is often realized at the expense of other objectives (Ma et al, 2020). Quantifying the trade-offs in the WEEN for cascade hydropower systems is a challenge and is key to a more comprehensive understanding of hydropower sustainability for decision-makers and stakeholders
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
