Shifts in Drought and Wetness Patterns: An SPI-based Taluka Level Analysis for Selected Districts of Saurashtra

Abstract

This study investigates long-term hydro-climatic variability in the Saurashtra region of western India by analysing taluka-level rainfall patterns using the Standardized Precipitation Index (SPI) for the period 1981–2023. Drawing on high-resolution ERA5-Land reanalysis data, drought and wetness characteristics were assessed for three major districts—Amreli, Junagadh, and Rajkot—across two contrasting climatic phases: 1981–2000, marked by recurrent droughts, and 2001–2023, characterized by strengthened monsoon rainfall. Results reveal pronounced shifts in drought–wetness regimes across all talukas. The pre-2000 period exhibited frequent moderate to severe droughts, with several talukas experiencing extreme drought conditions, particularly during 1984, 1986, and 1987. In contrast, the post-2000 period shows a substantial decline in drought frequency and complete disappearance of severe and extreme drought across all districts. Near-normal conditions now dominate 70–88% of the years, accompanied by increased occurrences of moderately, severely, and extremely wet years, especially during events such as 2007 and 2020. District-wise analysis highlights significant spatial differences, with Rajkot showing the strongest improvement, followed by Junagadh and Amreli. The findings demonstrate a clear regional transition from a drought-dominated regime toward a more stable and wetter monsoon climate. This taluka-level hydro-climatic assessment provides a robust scientific basis for strengthening regional climate adaptation strategies, enhancing drought monitoring systems, and supporting sustainable agricultural and water resource management in semi-arid regions such as Saurashtra.