Understanding hydrological regimes in the Krong No River under climate change scenarios and Boun Tua Srah hydropower operation

ABSTRACT Climate change and reservoir operations have significantly altered river flow regimes. Quantifying the individual contributions of these factors to different flow components is essential for understanding river dynamics and developing strategies to modify flow regimes. This study evaluates changes in the flow regime of the Krong No River under climate change scenarios and the operational activities of the Buon Tua Srah reservoir. To achieve this, the hydrological model HEC-HMS is integrated with IAHRIS 3.0 software. The results indicate that for the Krong No River, although climate change has a notable impact on future flow regimes, reservoir operations remain the dominant factor. These influences also vary across different flow components, with the most significant impact being the reduction in effective discharge events. This decline weakens the connection between the river and riparian ecosystems, leading to serious ecological consequences. By releasing a flood flow of 637 m3/s every 5 years, this strategy helps restore flow variability, reducing ecological stress while ensuring sustainable river management.