Spatial-temporal pattern and attribution factors of Yellow River’s streamflow seasonality and inter-annual variability

The Yellow River Basin in northern China, a large arid basin which is heavily influenced by anthropogenic activities. Streamflow variability at intra- and inter-annual scale directly links to the water supply for human and ecosystem, while received less attention and rarely considered together. Using gauge observations, this study developed a framework to quantify seasonal and inter-annual streamflow variability in the Yellow River Basin since 1960, then analyzed the influence from climatic and anthropogenic factors to spatial-temporal variation of streamflow variability. This study reveal a continuous decline by 29 % in seasonal streamflow variability since the 1960s. In contrast, inter-annual variability has intensified sharply since the late 2000s after previous decrease, with streamflow’s weighted coefficient of variation reached 0.24 in the last decade, exceeding the average since 1960. This rebound cannot be explained by climate alone. Instead, water extraction has substantially amplified variability, with effects intensifying downstream and reaching a 185 % increase in inter-annual variability in the lower reaches since 1998. While reservoir operations have moderated seasonality, they have failed to stabilize inter-annual variability. This study highlights the increasing role of anthropogenic influences in shaping hydrological variability, and underscores the need to integrate variability considerations into hydrological forecasting and water resource management. • A comprehensive framework to assess intra- and inter-annual streamflow variability. • Yellow River’s inter-annual streamflow variability has intensified after late 2000s. • Streamflow variability is mainly driven by recent anthropogenic activities.