Investigating the Future Flood and Drought Shifts in the Transboundary Srepok River Basin Using CMIP6 Projections

Quantifying the intensity and frequency of climatic extremes under the impacts of climate change is crucial for effective water resource management. In this study, we utilize the soil and water assessment tool hydrological model, robust indices, e.g., standardized precipitation index and standardized streamflow index as well as the interquartile range method for a comprehensive analysis of the river flow response to future climate scenarios towards 2090. Four general circulation models under two shared socioeconomic pathways have been used, including BCC-CSM2-MR, CanESM5, MIROC6, and MRI-ESM2-0. We aim to reveal the future impacts of extreme events and their potential consequences for local livelihoods and human well-being in the Srepok River basin—a major tributary of the Mekong River basin in Southeast Asia. Our findings include the following: 1) a significant discrepancy between extreme events found with more flood events projected toward 2090; 2) a shift in precipitation patterns with an increase in intensity is observed; and 3) a correlation between climatic extremes and regional characteristics has been identified. This work provides valuable insights into the anticipated changes in climatic extremes under the impacts of climate change and serves as the scientific basis for stakeholders and decision-makers to develop adaptative strategies and sustainable plans to enhance the region's resilience.