Spatial persistence in the Brahmaputra river: rescaled range and multiscaling analyses

Braided channel networks (BCNs) are highly dynamic fluvial systems characterized by multiple interweaving channels, whose configurations emerge from complex interactions between sediment transport and flow dynamics. This study proposes a novel methodological framework to analyze the scaling behavior of the braiding index Nwc, defined as the number of active wet channels within a given river reach. The approach integrates Rescaled Range (R/S) analysis with a fixed-size multifractal formalism, grounded in the Multifractal Detrended Fluctuation Analysis (MF-DFA) technique, to simultaneously capture long-range spatial dependence and multifractal scaling properties. The methodology is applied to 12 spatial datasets of the Brahmaputra River, derived from multisource satellite imagery spanning more than three decades and multiple spatial resolutions. Our results reveal a clear tendenc y toward persistence in the spatial organization of Nwc, as indicated by Hurst exponents consistently exceeding 0.5. This indicates the presence of significant long-range spatial correlations in the structure of BCNs. Furthermore, the stability of the multifractal spectrum widths, Δα, across all datasets highlights the presence of intrinsic self-organizing processes governing the braided river morphology, providing new insights into the scaling of complex fluvial systems.