Assessing Spatio‐Temporal Meteorological Drought Dynamics Across Indian Agro‐Climatic Zones: A Long‐Term Perspective

ABSTRACT Drought is among the most pervasive and devastating natural disasters, particularly in countries like India, where agriculture forms the backbone of the economy and supports most of the workforce. A prolonged deficiency in precipitation, often exacerbated by rising temperatures, adversely impacts water availability, agricultural productivity and socio‐economic stability. The situation is further worsened by the heterogeneous agro‐climatic conditions in India, where regional variations in rainfall, cropping patterns and hydrological regimes mean that drought affects different zones in distinct ways. India's agro‐climatic zones are increasingly experiencing intensified drought conditions due to rapid climatic changes and threatening agricultural productivity. This study investigates the spatio‐temporal dynamics of drought across India's agro‐climatic zones from 1951 to 2022, employing the Standardised Precipitation Evapotranspiration Index (SPEI) at both annual (SPEI‐12) and monsoon season specific (SPEI‐4) scales. The rainfall and temperature trends, as well as trend analysis of SPI‐12 and SPEI‐12, have been carried out using the modified Mann–Kendall (MMK) trend test. Long‐term analysis (1951–2022) shows a declining rainfall trend in 9 out of 14 agro‐climatic zones, with the most pronounced losses in the Upper and Middle Gangetic Plains, while warming trends are evident across almost all zones, intensifying evapotranspirative demand. The analysis reveals significant shifts in drought patterns, with increased frequency, intensity and spatial expansion of drought‐prone areas, particularly post‐1990. The MMK test detected statistically significant upward trends in drought indices across the Trans‐Gangetic Plains, Gangetic Plains, and Southern Plateau and Hills. SPEI‐based indices showed stronger increasing trends than SPI, highlighting the contribution of temperature‐driven evaporation demand [Correction added on 27 October 2025, after first online publication: The preceding two sentences have been corrected in this version.] The spatial analysis highlights emerging vulnerabilities in resilient regions, driven by declining monsoon reliability, rising temperatures and the additional impact of unsustainable anthropogenic practices, including the over‐extraction of groundwater and deforestation, which will worsen the situation. The study underscores the inadequacy of reactive drought management policies, which lack integration of climate change considerations and evolving drought dynamics. The findings emphasise the urgent need for proactive, region‐specific drought management strategies, including advanced monitoring systems, sustainable water resource management and climate‐resilient agricultural practices. By integrating rainfall, temperature, SPI and SPEI trend analysis with robust MMK testing, this study provides evidence‐based insights to guide climate‐resilient and drought‐adaptive policy frameworks across India's agro‐climatic zones.