ABSTRACT This figure summarizes the study framework, in which meteorological, topographic, land use, soil and station data are used to set up the SWAT model, followed by calibration, validation, and CMIP6 scenario selection to project discharge, environmental flow, soil water content, and evapotranspiration. Climate change has changed global hydro-meteorological responses, especially in the Bangladesh–India portion of the Ganges–Brahmaputra–Meghna (GBM) basin in Asia, which has suffered from excessive precipitation, temperature, floods, etc. Previous research used large-scale models, which are unlikely to improve projections, introduce greater uncertainty, and lack basin meteorological analysis. This study examines how climate change affects the hydrological and meteorological patterns in the Barak River Basin by applying a hydrologic model (Soil & Water Assessment Tool) coupled with bias-corrected and downscaled climate models. It evaluates both moderate and extreme scenarios to quantify changes in discharge, flow return period, seasonal variability, evapotranspiration (ET), and soil water content (SWC). Under an extreme scenario by the end of the century, results indicate an alteration in precipitation patterns, suggesting a potential increase of 31.38% in precipitation. This influences the basin's hydrology, as the annual maximum discharge is anticipated to increase by up to 67%. Furthermore, the return period of extreme flow events and the environmental flow is predicted to reduce by approximately 35 years and 8%, respectively. Moreover, ET and SWC are projected to fluctuate throughout the watershed. These alterations indicate an increased variability, which will affect water availability, flood risks, and agriculture in the region.
Turjo et al. (Thu,) studied this question.