Exploring the association between anomalies and multifractality variations in river flow time series.

Monitoring and predicting river floods have always been of concern for hydrologists. Anomalies in flow patterns alert us of upcoming events. The effect of such anomalies on the multifractality and nonlinear dynamics of the river flow is investigated in this research. The river flow of the River Trent in England from 2018 to 2019 was dissected using the multifractal, power spectrum, and phase space reconstruction techniques. Results show a reduction in multifractality strength before the anomalies in the time series. Moreover, receding trajectories from the attractor in the phase space and augmentation of the power spectrum confirmed a decline in flow multifractality due to anomalies. A compliance comparison of multifractality reduction before anomalies in river flow leads to predicting river floods approximately 12 days in advance. Furthermore, if the multifractal strength does not return to its equilibrium, this is a warning that floods are expected in the near future (less than 10 days). [ABSTRACT FROM AUTHOR]