Power generation dispatching and risk analysis of the Qingjiang cascade hydropower stations under climate change

Climate change alters river runoff regimes, affecting the safe operation of hydropower stations. This study proposed an optimization scheduling and risk analysis framework for cascade hydropower under climate change using the Qingjiang cascade hydropower stations as a case study. The framework has three stages. Firstly, a hydrological model coupling GCMs with SWAT under CMIP5 scenarios is established to predict future runoff. Secondly, cascade hydropower optimization scheduling under climate change is performed using the POA (Progressive Optimization Algorithm). Thirdly, a risk assessment index system is established, including risks of insufficient power generation, insufficient output, and water abandonment. The POMR (Probability Optimization Method for the Risk) is applied to calculates power scheduling risks. Results show that the simulated annual average runoff at Changyang Station increases by 6.0, 8.7, and 13.2% under the RCP2.6, RCP4.5, and RCP8.5 scenarios, respectively. Annual power generation for the Qingjiang cascade is projected to rise by 6.2-16.5%, with increases of 5.2-12.9% during flood seasons and 7.5-19.9% in non-flood seasons. Comprehensive risk rates decline to 0.1767, 0.1706, and 0.1630 across the scenarios. This research provides scientific and technical support for managing water resources and operating the Qingjiang cascade under climate change.