Concurrent Hydro-climate Drought Extremes in Eastern India Under Climate Change Scenarios

The interplay of hydro-climate extremes poses critical challenges to water resource management, particularly in agriculture-dominated regions where climate variability significantly affects crop production, irrigation demands, and overall agricultural sustainability. The Eastern India river basins, including the Brahmani and Baitarani, are significantly dependent on monsoonal rainfall for irrigation, drinking water, and hydroelectric power generation, making them vital for analyzing concurrent hydro-climate drought extremes. This study investigates the concurring dynamics of hydro-climate droughts driven by changes in precipitation patterns, temperature extremes, and declining river flows. The Standardized Precipitation Index (SPI), Standardized Temperature Index (STI), and Standardized Runoff Index (SRI) are employed to analyze precipitation, temperature, and runoff extremes, focusing on dry-wet dynamics within the consecutive seasons. This analysis is conducted using historical data (1979–2018) and future climate projections (2021–2060) from the Coupled Model Intercomparison Project Phase 6 (CMIP6). Additionally, we have analyzed trends in precipitation and temperature variability alongside their influence on runoff. Our findings reveal that the frequency and intensity of concurrent hydro-climate drought events are projected to increase within the seasons, with significant impacts on the monsoon season, including reduced rainfall, extended dry spells, and depleted runoff. These changes exacerbate water scarcity and heighten agricultural vulnerabilities in the region. The interconnected nature of these extremes highlights the need for integrated water resource management strategies that prioritize climate resilience. This research emphasizes the importance of adaptive measures to mitigate the socio-economic impacts of hydro-climate droughts in Eastern India, ensuring the sustainability of ecosystems and livelihoods in the face of an uncertain future climate.