Shifts in Drought and Wetness Patterns: An SPI-based Taluka Level Analysis for Selected Districts of Saurashtra
P. A. Pandya *
Research, Testing and Training Centre (RTTC), Junagadh Agricultural University, Junagadh, India.
Paras Hirapara
Research, Testing and Training Centre (RTTC), Junagadh Agricultural University, Junagadh, India.
D. D. Vadalia
Research, Testing and Training Centre (RTTC), Junagadh Agricultural University, Junagadh, India.
Devrajsinh Thakor
ICAR-Indian Institute of Soil and Water Conversation, Vasad Centre, India.
G. V. Prajapati
Research, Testing and Training Centre (RTTC), Junagadh Agricultural University, Junagadh, India.
S. H. Parmar
Research, Testing and Training Centre (RTTC), Junagadh Agricultural University, Junagadh, India.
D. J. Patel
Research, Testing and Training Centre (RTTC), Junagadh Agricultural University, Junagadh, India.
*Author to whom correspondence should be addressed.
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.
Keywords: Standardized Precipitation Index (SPI), drought analysis, wetness patterns, ERA5-Land, taluka-level, climate variability