Quantifying impacts of lakes on baseflow dynamics in headwaters of the Yellow River, Tibetan Plateau

Abstract

The alteration of lakes modifies the catchment landscapes, and thus the associated hydrological processes (e.g., baseflow). However, the role of lakes in the baseflow dynamics of the Tibetan Plateau is unclear under the effects of climate change. Here, the revised baseflow separation is considered for a quasi-paired catchment. A no-lake scenario is then constructed using machine learning (ML) to quantify the influence of lakes on baseflow signatures. Our results indicate that: (i) The winter baseflow duration curve is in good agreement with the summer baseflow duration curve (R2 = 0.982, %BiasV = 15.38%) within the lake catchment; (ii) Lakes show bidirectional (positive and negative) contributions to the baseflow index, and exhibit a strong reduction effect on the frequency of high baseflow days (−46.82%); (iii) Lakes amplify the influence of temperature on the frequency of both high baseflow days and low baseflow days, while attenuating the impact of soil moisture on rising limb density. These results reveal that lakes act as fundamental modulators, altering how physiographic and climatic variabilities propagate into baseflow behavior in headwater systems. This study enhances our understanding of how lakes regulate catchment baseflow dynamics, supporting the design of water management strategies under future changing conditions. Show more