Souza et al. (2026) Multifractal assessment of hydroclimatic variability in Midwest Brazil using the hydroclimatic balance index (HBI): a comparison with the standardized precipitation index (SPI)

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

Identification

• Journal: Theoretical and Applied Climatology
• Year: 2026
• Date: 2026-09-24
• Authors: Amaury de Souza, José Francisco de Oliveira-Júnior
• DOI: 10.1007/s00704-026-06467-6

Research Groups

Not available from the abstract.

Short Summary

This study investigates the multifractal characteristics of hydroclimatic variability in the capital cities of Midwest Brazil, revealing pronounced multifractal dynamics with strong long-range dependence and an intensification of persistence and intermittency in recent decades.

Objective

• To investigate the multifractal characteristics of hydroclimatic variability (monthly precipitation, actual evapotranspiration, and a hydroclimatic balance index) in the capital cities of Midwest Brazil.

Study Configuration

• Spatial Scale: Capital cities of Midwest Brazil.
• Temporal Scale: Monthly data from 1958 to 2024. Sub-periods analyzed: 1958–1990 and 1991–2024.

Methodology and Data

• Models used: Multifractal Detrended Fluctuation Analysis (MFDFA) for quantifying scaling behavior, persistence, and variability heterogeneity. A 12-month standardized hydroclimatic balance index (HBI) was constructed, analogous to the Standardized Precipitation Evapotranspiration Index (SPEI).
• Data sources: TerraClimate dataset for monthly precipitation (ppt) and actual evapotranspiration (aet).

Main Results

• Pronounced multifractal dynamics were observed across all capital cities.
• Generalized Hurst exponents ranged from 0.87 to 0.98, indicating strong long-range dependence in hydroclimatic fluctuations.
• Singularity spectrum width (Δα) varied spatially, with Campo Grande and Goiânia exhibiting the highest multifractal strength.
• Precipitation displayed stronger intermittency than evapotranspiration, confirming rainfall variability as the primary driver of hydroclimatic complexity.
• Linear trend analysis of annual series revealed weak and statistically non-significant tendencies.
• Comparison of sub-periods (1958–1990 vs. 1991–2024) suggested increased persistence and intermittency in recent decades, indicating an intensification of hydroclimatic variability.

Contributions

• Quantifies the multifractal characteristics of hydroclimatic variability in a tropical continental region (Midwest Brazil), providing insights into its complex dynamics.
• Highlights the limitations of traditional linear trend analysis and emphasizes the relevance of complexity-based drought diagnostics for understanding hydroclimatic variability and change.
• Demonstrates an intensification of hydroclimatic variability in recent decades through increased persistence and intermittency, offering a new perspective on regional climate trends.

Funding

Not available from the abstract.

Citation

@article{Souza2026Multifractal,
  author = {Souza, Amaury de and Oliveira-Júnior, José Francisco de},
  title = {Multifractal assessment of hydroclimatic variability in Midwest Brazil using the hydroclimatic balance index (HBI): a comparison with the standardized precipitation index (SPI)},
  journal = {Theoretical and Applied Climatology},
  year = {2026},
  doi = {10.1007/s00704-026-06467-6},
  url = {https://doi.org/10.1007/s00704-026-06467-6}
}