Exploring a Novel Reservoir Impoundment Operation Framework for Facilitating Hydropower Sustainability

Abstract

Reservoir impoundment operation has far-reaching effects on the synergies of hydropower output, floodwater utilization, and carbon fluxes, but flood risk is significantly increasing, which is especially true when shifting to earlier impoundment timings and lifting reservoir water levels. This study proposed a novel reservoir impoundment operation framework driven by flood prevention, hydropower production, floodwater utilization, and carbon emission management. The Three Gorges Reservoir in the Yangtze River was selected as a case study. The results demonstrated that flood prevention safety could be guaranteed with the initial impoundment timings on and after the first of September. The best scheme of reservoir impoundment operation could efficiently boost synergistic benefits by enhancing 2.98 billion kW·h (8.8%) hydropower output and 6.4% water impoundment rate and decreasing greenhouse gas (GHG) fluxes and carbon budget by 28.15 GgCO2e/yr (4.6%) and 0.44 (23.1%), respectively, compared with the standard operation policy. This study can not only provide scientific and technical support for reservoir impoundment operations, benefiting water–carbon synergies, but can also suggest policymakers with various favorable advancing impoundment timing and lifting reservoir water level schemes to experience related risks and benefits in the interest of hydropower sustainability.