青海湖水量平衡动态特征与驱动机制研究OA

[Objective]The continuous rise in the water level of Qinghai Lake poses a threat to surrounding ecological security and infrastructure.Clarifying the dynamic changes in its water balance and the core driving factors is crucial for ecological protection and risk prevention and control.[Methods]The distributed hydrological model SWAT,isotopic tracers,and structural equation modeling(SEM)were used to investigate the medium-to long-term hydrological evolution and driving mechanisms of Qinghai Lake under climate change.[Results]The result indicated that the water level changes of Qinghai Lake exhibited distinct phased characteristics.Before 2004,it declined at an average rate of 0.078 m per year,and then recovered at a rate of 0.187 m per year,with the recovery rate being 2.4 times that of the previous decline rate.Water balance exhibited two typical states.The positive balance state was primarily characterized by runoff dominance(37.8％)synergized with precipitation(31.6％),while the negative balance state was characterized by evaporation dominance(41.5％)and suppressed runoff(25.9％).A critical threshold for system imbalance was identified as evaporation exceeding 40× 108 m3/a and runoff below 14× 108 m3/a.Groundwater was a key regulatory component,with an average annual recharge of 8.11 × 108 m3.Notably,the recharge in 2024 reached(19.01±3.52)× 108 m3,with a peak summer recharge rate of(6.99±1.24)× 106 m3/d.Furthermore,the recharge in the northern region was significantly higher than in other regions.[Conclusion]The spatiotemporal coupled driving mechanisms of precipitation-runoff-groundwater recharge are revealed,providing a scientific basis for the water resource management of Qinghai Lake.