Tiwari et al. (2026) Multi-dimensional changes in drought patterns across India

Identification

• Journal: Climatic Change
• Year: 2026
• Date: 2026-01-01
• Authors: Arpit Tiwari, Soumi Chakravorthy, R. Anil Kumar, Ananya Karmakar, Satyaban B. Ratna
• DOI: 10.1007/s10584-025-04102-3

Research Groups

• Christ University, Lavasa, Pune, India
• India Meteorological Department, Shivajinagar, Pune, India

Short Summary

This study comprehensively assesses drought trends and hydroclimatic variability across six major geographical zones in India from 1971 to 2020, revealing increasing dryness in Northeast India, the Himalayas, and the Indo-Gangetic Plain, while Western and Peninsular regions show wetting trends, driven by complex interactions of rainfall and temperature extremes.

Objective

• To present a comprehensive assessment of drought trends and hydroclimatic variability across six major geographical zones in India, quantifying changes in drought conditions and the emergence of non-analogue climates using advanced climate change metrics and the Standardized Precipitation Evapotranspiration Index (SPEI).
• To identify the dominant drivers of drought within different climatic systems across the country.

Study Configuration

• Spatial Scale: Six major geographical zones across India (Western, Central, Himalayan, Indo-Gangetic Plain (IGP), Peninsular, and Northeast India). Gridded data covering latitudes 6.76°–37.08°N and longitudes 68.15°–97.42°E (3721 grid points).
• Temporal Scale: 50-year period from 1971 to 2020 for climate parameters and SPEI. Baseline period for climatic extremes: 1951–1980. Target decades: 1981–1990, 1991–2000, 2001–2010, 2011–2020.

Methodology and Data

• Models used:
  • Standardized Local Anomalies (SLA)
  • Novel Climate Scores (NCS)
  • Changes in probability of local climate extremes (using 95th and 5th percentile thresholds)
  • Standardized Precipitation Evapotvaporation Index (SPEI)
  • Hargreaves method for Reference Evapotranspiration (ET₀) calculation
  • Standardized Euclidean Distance (SED) for NCS
  • Cronbach's reliability test for SPEI time scales
• Data sources:
  • India Meteorological Department (IMD) daily gridded rainfall data (0.25° × 0.25° resolution, 1901–present)
  • IMD daily maximum and minimum temperature data (0.5° × 0.5° resolution, 1951–present)

Main Results

• A significant increase (> 25%) in the occurrence of extreme climate events was observed across India, particularly in the Himalayas, Western, Peninsular, and Northeast regions, compared to the 1951–1980 baseline.
• Standardized Local Anomalies (SLA) showed intensified warming (SLA > 5) over the Indo-Gangetic Plain (IGP), Western India, and the Southern Peninsular region.
• Novel Climate Scores (NCS) indicated the emergence of unprecedented climate conditions, with the highest scores (> 0.2) observed in Southeast India and the Himalayan region, increasing over the past 40 years.
• The 12-month SPEI was identified as the most consistent and reliable timescale for drought assessment across India.
• SPEI trends (1971–2020) revealed increasing dryness in Northeast India, the Himalayas, and the Indo-Gangetic Plain, linked to declining monsoonal rainfall and rising temperatures.
• Conversely, Western and Peninsular regions exhibited wetting trends, driven by increased rainfall and convective precipitation events.
• Rainfall was identified as the dominant drought driver during the monsoon season (correlation with SPEI: r = 0.59).
• High maximum temperatures intensified drought conditions in pre- and post-monsoon seasons by enhancing evaporative demand (pre-monsoon Tmax-SPEI correlation: r = -0.36; post-monsoon Tmax-SPEI correlation: r = -0.32).
• Minimum temperature showed regional effects, contributing to drying in the IGP and Himalayas, but a slight moistening signal in Peninsular India.
• Regional SPEI trends (1971-2020) indicated wetting in Western (+0.343) and Peninsular (+0.442) regions, and drying in Central (-0.07), Himalayan (-0.415), IGP (-0.47), and Northeast (-0.415) regions.

Contributions

• Provides a comprehensive, multi-dimensional assessment of drought patterns and hydroclimatic variability across six major Indian geographical zones, addressing limitations of previous monsoon-centric or localized studies.
• Integrates advanced climate change metrics (SLA, NCS, probability of extremes) with SPEI to quantify not only drought conditions but also the emergence of novel and non-analogue climates.
• Identifies the dominant climatic parameters (rainfall, Tmax, Tmin) driving drought across different seasons and regions, highlighting their complex interactions.
• Offers a comprehensive framework for monitoring hydroclimatic shifts and their regional impacts, providing a scientific basis for region-specific adaptation strategies and aligning with national drought management plans.

Funding

Not applicable.

Citation

@article{Tiwari2026Multidimensional,
  author = {Tiwari, Arpit and Chakravorthy, Soumi and Nanjundan, Preethi and Kumar, R. Anil and Karmakar, Ananya and Ratna, Satyaban B.},
  title = {Multi-dimensional changes in drought patterns across India},
  journal = {Climatic Change},
  year = {2026},
  doi = {10.1007/s10584-025-04102-3},
  url = {https://doi.org/10.1007/s10584-025-04102-3}
}