Long-Term (1951–2020) Climatic Variability and Extremes across Agro-Climatic Zones and Districts of Chhattisgarh, India

Abstract

This study compares important meteorological characteristics across two time periods, 1951–1986 and 1986–2020, using IMD 0.25° × 0.25° gridded datasets of Tmax, Tmin, and rainfall to examine long-term climate variability across 27 districts (as of 2020) and three agro-climatic zones of Chhattisgarh, India. The analysis incorporates district-level meteorological variables such as diurnal temperature range (DTR), annual rainfall, number of rainy days, maximum and minimum temperatures, and extreme climate indices including the Cold Spell Duration Index (CSDI), Warm Spell Duration Index (WSDI), Consecutive Dry Days (CDD), and Consecutive Wet Days (CWD). These indices where percentile methods which were calculated using RClimDex, an R package developed by ETCCDI. The findings show that although parts of the Bastar Plateau Zone experienced an increase in rainfall, the Chhattisgarh Plain and Northern Hill Zones exhibited a significant decline in annual rainfall. Maximum temperatures and DTR increased in several regions, while dry periods became longer and more frequent. Most districts also showed a substantial rise in warm spells and a decrease in cold spells, indicating a shift toward a warmer and more variable climate. these changes in temperature extremes and rainfall patterns signal heightened climate risks, particularly for agriculture and water resources. the results emphasize the need for localized adaptation strategies, climate-resilient agricultural practices, and informed planning by policymakers and stakeholders to mitigate future vulnerabilities in the region.