Climate change-induced hotspot identification: a multi-variable approach for the Godavari River Basin

Climate-induced extreme events significantly impact river basin hydrology. Region-specific strategies are required to address the spatial and temporal variations in precipitation and temperature patterns. This study develops a framework to identify vulnerable hotspots within the Godavari River Basin (GRB) by analyzing climate-induced changes in hydrological (streamflow and groundwater) and agricultural (normalized difference vegetation index (NDVI) and crop yield) variables. Seventeen indices that characterize the temperature and precipitation extremes were used to assess climate change, and a combined index (CI) was developed using principal component analysis (PCA) to capture their collective impact. Vulnerable hotspots were identified by examining the relationship between CI and hydrological and agricultural variables using Pearson correlation and trend analysis, at various time scales for historical and future periods under four Shared Socioeconomic Pathways. The following findings were obtained from the study: (a) vulnerability assessment in the historical period reveals that streamflow is highly sensitive to climate extremes in sub-basins such as Manjra, Wardha, Pranahita, Middle Godavari, and Wainganga, covering 58%, 43%, 42%, 39%, and 26% of the basin areas, respectively, at the annual scale; (b) vulnerability of groundwater level is notable in Lower-, Upper-, Middle- Godavari, and Wardha, covering 50%, 32%, 25%, and 18% of the basin areas, respectively, indicating significant climate-induced fluctuations across these regions; (c) parts of Wardha and Middle Godavari were identified as hotspots for crop yield; (d) future projections suggest an escalation in vulnerable hotspots by over 50%, particularly under the SSP585 scenario.