Bartolo et al. (2026) Spatial persistence in the Brahmaputra river: rescaled range and multiscaling analyses

Identification

• Journal: Stochastic Environmental Research and Risk Assessment
• Year: 2026
• Date: 2026-04-01
• Authors: Samuele De Bartolo, Carlo De Michele, Leonardo Primavera
• DOI: 10.1007/s00477-026-03204-3

Research Groups

• Department of Engineering for Innovation, EUropean Maritime Environmental Research (EUMER), University of Salento, Lecce, Italy
• Department of Civil and Environmental Engineering, Politecnico di Milano, Milano, Italy
• Department of Physics, University of Calabria, Rende, Cosenza, Italy

Short Summary

This study proposes a novel methodological framework integrating Rescaled Range (R/S) analysis with Multifractal Detrended Fluctuation Analysis (MF-DFA) to analyze the spatial scaling behavior and persistence of the braiding index ((N_{wc})) in the Brahmaputra River. The findings consistently reveal significant long-range spatial persistence and a stable multifractal signature, indicating that intrinsic self-organizing processes govern the river's morphology.

Objective

• To robustly estimate the Hurst exponent and characterize the long-range spatial dependence and multifractal scaling properties of the braiding index ((N_{wc})), defined as the number of active wet channels, in the Brahmaputra River.

Study Configuration

• Spatial Scale: Brahmaputra River, with longitudinal planimetric extents ranging from approximately 218 kilometers to 355 kilometers. Spatial resolutions of satellite imagery used were 15 meters × 15 meters, 24 meters × 24 meters, 30 meters × 30 meters, and 80 meters × 80 meters.
• Temporal Scale: 12 spatial datasets derived from multisource satellite imagery spanning over three decades, from 1976 to 2007.

Methodology and Data

• Models used: Rescaled Range (R/S) Analysis, Multifractal Detrended Fluctuation Analysis (MF-DFA).
• Data sources: Multisource satellite imagery of the Brahmaputra River, including Landsat MSS, Landsat TM, IRS LISS, and ASTER. The data consists of discrete spatial series representing the number of active wet channels ((N_{wc})) along the river's longitudinal axis.

Main Results

• Spatial Persistence: Both R/S analysis and MF-DFA consistently showed Hurst exponents (H) greater than 0.5 (R/S: H between 0.897 and 0.999; MF-DFA H(0): between 0.764 and 0.943), indicating significant long-range spatial correlations and persistent behavior in the spatial organization of (N_{wc}).
• Multifractal Nature: MF-DFA confirmed the multifractal nature of the (N_{wc}) signal. The widths of the multifractal spectra ((\Delta \alpha)) were found to be relatively uniform across all 12 datasets, with an average value of 0.738.
• Self-Organizing Processes: The stability of the multifractal spectrum widths suggests the presence of intrinsic self-organizing processes governing the braided river morphology, maintaining a consistent hierarchy of spatial structures over time despite variations in channel configuration and discharge.
• Discharge Invariance: The Hurst exponents showed substantial invariance with discharge, aligning with previous studies that indicate braided river morphology exhibits stabilized spatial persistence of active channels with increasing discharge or stream power.

Contributions

• Introduces a robust methodological framework combining R/S analysis and MF-DFA for a comprehensive characterization of spatial persistence and multifractality in braided river systems.
• Provides direct and quantitative evidence of long-range spatial correlations and a stable multifractal signature in the Brahmaputra River's active channel network over three decades.
• Offers new insights into the underlying self-organizing processes that govern the morphology and complexity of large braided fluvial systems.
• Enhances the understanding of the spatial organization of multi-thread channel networks, with direct implications for hydraulic modeling and sediment transport analysis.

Funding

• RETURN project (Multi-risk science for resilient communities under a changing climate) with Extended Partnership.
• European Union Next-GenerationEU, National Recovery and Resilience Plan—NRRP, Mission 4, Component 2, Investment 1.3—D.D. 1243 2/8/2022, PE0000005.

Citation

@article{Bartolo2026Spatial,
  author = {Bartolo, Samuele De and Michele, Carlo De and Primavera, Leonardo},
  title = {Spatial persistence in the Brahmaputra river: rescaled range and multiscaling analyses},
  journal = {Stochastic Environmental Research and Risk Assessment},
  year = {2026},
  doi = {10.1007/s00477-026-03204-3},
  url = {https://doi.org/10.1007/s00477-026-03204-3}
}