This study investigates the climate change impacts on
the performance
of the Thac Mo reservoir in Vietnam throughout the release duration
from December to June of the following year. The adaptative optimization
operating rules during two periods, 2029–2064 and 2064–2099,
were analyzed. Precipitation and temperature of three shared socioeconomic
pathway (SSP) scenarios (SSP1–P2.6, SSP2–4.5, and SSP5–8.5)
of the Coupled Model Intercomparison Project Phase 6 (CMIP6) derived
from the global climate model (GCM) Meteorological Research Institute
Earth System Model version 2.0 (MRI-ESM2–0) were used for inflow
prediction. Due to the decreased inflow, the current operating rule
would almost lead to a decrease in hydropower production of two periods
of SSP1–P2.6, SSP2–4.5, and SSP5–8.5 scenarios
of −3.9, 0.7, −7.6, −6.7, −6.3, and 7.0%
and an increase in water scarcity, with the respective amount of water
deficit by 20.4, 6.8, 33.2, 31.3, 30.2, and 28.3% compared to the
base period (1987–2022). The improved power production of 7.1,
7.1, 7.3, 6.2, 6.9, and 6.8% and reduced water shortage of −40.2,
−42.7, −37.2, −43.4, −40.8, and −39.0%
can be achieved by applying the nondominated sorting genetic algorithm
II (NSGA-II) optimization technique under different periods and scenarios.
This approach has the potential to mitigate climate change effects
on future reservoir operations.