Tiwari et al. (2026) Transition in Köppen Climate Zones and Its Impacts on Hydroclimatic Extremes Across India

⚠️ Warning: This summary was generated from the abstract only, as the full text was not available.

Identification

• Journal: International Journal of Climatology
• Year: 2026
• Date: 2026-04-08
• Authors: Arpit Tiwari, Preethi Nanjundan, R. Anil Kumar, Satyaban B. Ratna
• DOI: 10.1002/joc.70381

Research Groups

Not available in the abstract.

Short Summary

This study investigates how spatial shifts in Köppen–Geiger climate zones across India between 1961–1990 and 1991–2020 influence long-term drought characteristics, revealing an expansion of arid zones and contraction of temperate zones, leading to more frequent and intense droughts driven by rising temperatures and increased evapotranspiration.

Objective

• To examine how spatial changes in Köppen–Geiger climate zones between two climatological periods (1961–1990 and 1991–2020) are influencing long-term drought characteristics across India.

Study Configuration

• Spatial Scale: India, assessing five major climate categories: tropical, arid, temperate, continental, and polar.
• Temporal Scale: Comparison between two 30-year climatological periods: 1961–1990 and 1991–2020.

Methodology and Data

• Models used: Standardised Precipitation Index (SPI) and Standardised Precipitation Evapotranspiration Index (SPEI).
• Data sources: High-resolution gridded rainfall and temperature data from the India Meteorological Department.

Main Results

• A noticeable expansion of the arid zone by 3.86% was observed.
• A contraction of the temperate zone by 6.94% was observed, indicating a transition toward warmer and drier climates.
• These spatial shifts have altered regional drought behaviour, with formerly moderate zones experiencing more frequent and intense droughts.
• The arid and tropical zones, where expansion is observed, show increasing drought severity.
• Increasing drought severity is largely driven by rising evapotranspiration due to temperature increases of 0.12 °C–0.25 °C/decade (maximum temperature) and 0.10 °C–0.20 °C/decade (minimum temperature).
• Regions where the temperate climate is receding are showing a loss of climatic buffering capacity against drought.
• SPEI captures more widespread and severe drought events than SPI, highlighting the increasing role of thermal stress in water balance anomalies.

Contributions

• Highlights that changes in the spatial extent of climate zones are a key driver of evolving drought patterns in India.
• Emphasises the necessity of recognising these shifts for improving temperature-sensitive drought monitoring.
• Provides a basis for formulating zone-specific adaptation strategies in the face of accelerating climate change.

Funding

Not available in the abstract.

Citation

@article{Tiwari2026Transition,
  author = {Tiwari, Arpit and Nanjundan, Preethi and Kumar, R. Anil and Ratna, Satyaban B.},
  title = {Transition in Köppen Climate Zones and Its Impacts on Hydroclimatic Extremes Across India},
  journal = {International Journal of Climatology},
  year = {2026},
  doi = {10.1002/joc.70381},
  url = {https://doi.org/10.1002/joc.70381}
}