Unveiling the multifractal signatures of rainfall temporal organization: New insights into the complexity assessment of precipitation patterns over northeast Algeria

In recent years, the analysis of rainfall temporal structure becomes a fundamental area of research for hydrologists seeking to understand hydro-climatic variability, especially in regions affected by the consequences of climate change. In this context, the present study provides a comprehensive analysis of the multifractal signatures behavior of temporal fluctuation in daily rainfall series measured in northeast Algeria through the Multi-Fractal Detrended Fluctuation Analysis (MF-DFA) method. The analysis of rainfall time series (1981–2019) across a wide range of time scales from 80 to 800 days shows the presence of a multiple scaling property that characterizes a significant multifractal behavior. The estimation of multifractal parameters leads to an average value of α ₀  = 0.642 ± 0.041 for the central Hölder exponent, showing a persistence process reflecting long-term correlation dynamics. Furthermore, the distribution of multifractal spectrum width ( Δα ) values over a wide range (0.457 ≤  Δα  ≤ 1.324) exhibits a significant heterogeneity in the multifractality degree between the studied stations. This research explores, in particular, the possible links between multifractal parameters and geo-climatic factors that explain their spatial variability. Correlation analysis with latitude, altitude, and annual rainfall shows that sub-humid coastal areas exhibits greater structural complexity in rainfall variability than semi-arid regions. These relationships suggest a new approach based on multifractal signatures as robust physical indicators for the regionalization of precipitation in northern Algeria. The results of this study demonstrate that multifractal analysis provides a solid framework for unveiling the complexity of rainfall dynamics, which provides useful information for better water resource management in the Mediterranean basin.