Assessing the effects of climate change on the streamflow of the major river basins of central India

Five river basins of Central India The impacts of climate change on streamflow at a regional scale are assessed using Coupled Model Intercomparison Project Phase 6 (CMIP6) data. This study focuses on the hydrological assessment of multiple river basins, offering a more realistic understanding of the region's water dynamics. Historical data (1995–2024) from Global Circulation Models (GCMs) are compared with observations to determine the most suitable GCM for the region. The hydrological model is calibrated and then used to project streamflow across four Shared Socio-Economic Pathways (SSPs) to understand how climate change impacts the region's water resources from 2020 to 2045. Climate change impact assessments are commonly conducted at broader spatial scales. This may fail to capture the spatial variability in hydrological responses. This study emphasises the necessity of basin-scale climate impact assessments to adequately capture spatial heterogeneity in hydrological responses to climate change. The projected streamflow responses among basins within the state boundary show significant variability despite exposure to similar climatic conditions. The Narmada River shows a 26.75 % increase under SSP1–2.6. The Betwa and Sindh show a 35 % increase under SSP3–7.0, while the Chambal flow decreases by 16.9 % (SSP2–4.5) and 2.6 % (SSP5–8.5). The outcome of this study will support decision-making for sustainable water resource management and climate adaptation planning at the basin scale. • GCM performance evaluation shows MPI-ESM1–2-LR is the best model for central India. • Contributes to state-level climate action planning for water security in India. • Climatology analysis of the region shows high variability across basins. • Future streamflow increases in the Narmada but decreases in the Chambal. • Basin-wise water management is essential based on the findings