Streamflow projections under climate change framework for the Mahanadi River catchment, India

Thirteen GCMs under Coupled Model Intercomparison Project-6 were analysed against IMD grid data using compromise programming (CP) to identify the optimal model. This innovative multi-criteria decision-making approach balances competing performance metrics to enhance model selection. The CP matrix indicated that the MPI-ESM1-2-HR model optimally simulates streamflow using the IMD-calibrated data. This study also examines basin hydrology and development impacts, emphasizing spatiotemporal climate variability. Spatial proximity-based regionalization identified Kurubhata, Bamnidih, and Basantpur as suitable gauged sites for streamflow projections at Kalma using Soil and Water Assessment Tool modelling. Under the SSP245 scenario, streamflow projections for 2019–2050 indicate increases of 44.67%, 27.88%, and 38.10% at Jondhra, Seorinarayan, and Basantpur, respectively. Water yield at Kalma is projected to rise by 96% from a baseline of 396.26 mm, and monsoonal precipitation at the basin outlet is expected to increase by 91.81 mm/year.