A Framework for Analysing Multi-Timescales Evolution Patterns in Precipitation–Streamflow Relationship

Abstract

The precipitation–streamflow relationship (PSR) is one of the most crucial aspects of hydrological process studies. Previous studies have analysed the changes of the PSR at specific timescales (e.g., annual or seasonal), overlooking the characteristics of the PSR across multiple timescales and the changes that occur over time. This study presented an integrated framework to address these issues from three perspective: the inconsistencies, the response sensitivity of streamflow to precipitation and the PSR across multiple oscillation periods. This study analysed monthly streamflow and precipitation data from three representative reaches located in the upper and middle sections of the Yellow River Basin from 1961 to 2021. The results indicate that the proposed integrated framework effectively reveals the evolving patterns of the PSR. The evolution patterns of PSR vary across different time scales. Notably, the inconsistencies in PSR variations in the middle and upper reaches of the Yellow River are significant and manifest differently across various timescales. These differences were particularly pronounced in the middle reaches when comparing the periods before and after 2000. The changes in PSR varied among different oscillation periods, and an examination of the resonant period variability revealed a shift from strong-to-weak resonance within the 32–64-month period, followed by a weak-to-strong transition within the 128-month period. This study has significantly enhanced our understanding of the evolution of the PSR and has provided valuable insights for effectively managing hydrological processes in a changing environment.