封闭性湖泊水量收支变化是研究湖泊对气候变化响应的理想研究对象，但现有研究多关注青藏高原湖泊的长期水量变化。由于数据稀缺，青藏高原湖泊水量年内动态变化及平衡要素的贡献尚不明确，制约了青藏高原湖泊水量收支和对气候变化响应的研究。本文基于巴木错水文气象观测数据、再分析资料以及水量平衡方程和入湖径流量计算方法，分析了巴木错 2021-2023年季风期水量平衡方程各要素——湖面降水 P、入湖径流 Rs、湖面蒸发 E、水位 H和水位差值 ΔH的动态变化特征；不同月份、年份的水量平衡因子相对贡献率；以及水文要素和气象要素——气温、向下辐射和相对湿度的年际变化。研究结果表明：（1）巴木错水量收支具有显著年际差异，其中 2021年充沛的 P与 Rs驱动 H上升，2022年 P与Rs骤减导致H下降，2023年P与Rs的增强抵消E的增强使得H再次上升；（2）ΔH受Rs与E主导调控，月尺度上Rs贡献率呈“V”型波动、E贡献率反向变化，年际尺度上Rs主导正向波动（2021年和2023年）、E主导负向波动（2022年）；（3）气象要素通过调节P-E动态平衡影响ΔH，2021年中等气温、高湿度和中等辐射条件下，E/P比值相对中等，ΔH正向波动（+231 mm）；2022年，气温升高、湿度降低、辐射增强导致 E/P值上升，叠加 P和 Rs减少，引发 ΔH 负向波动（-75 mm）；2023年，气象条件改善，E/P比值下降，水热条件的恢复驱动ΔH正向变化（+350. 6 mm）。本研究揭示了典型季风区湖泊水循环的特征，对支撑“亚洲水塔”生态安全屏障建设和推动高原可持续发展有重要意义。

The variation in water budget of closed lakes serves as an ideal research subject for studying lake responses to climate change. However，most existing studies focus on the long-term water volume changes of lakes on Qinghai-Xizang Plateau. Due to data scarcity，the intra-annual dynamics of water budgets and the contributions of balance components in these lakes remain unclear，hindering research on water budget dynamics and cli‐ mate change responses. Base on hydrological-meteorological observation data，reanalysis datasets，water balance equations，and inflow runoff calculation methods，this study analyzes the dynamic characteristics of water balance components［lake surface precipitation（P），inflow runoff（Rs），lake surface evaporation（E）］，lake level（H）and lake level difference（ΔH））in Bamu Co during the 2021-2023 monsoon periods；the relative contributions rates of water balance factors in different months and years；along with the interannual variations in meteorological elements including air temperature，downward radiation，and relative humidity. The results show that：（1）The water budget of Bamu Co exhibits significant interannual variation. In 2021，abundant P and Rs drove in H. In 2022，sharp declines in P and Rs led to a drop in H. In 2023，increases in P and Rs offset the intensified E，resulting in another rise in H.（2）ΔH is mainly regulated by Rs and E. On the monthly scale，the contribution of R s displays a “V”-shaped，while E shows an opposite trend. On the interannual scale，Rs plays a dominant role in positive variations（2021 and 2023），whereas E dominates negative variations（2022）.（3）Meteorological elements influenced ΔH through P-E balance adjustments：moderate temperature，high humidity，and medium radiation in 2021 maintained medium E/P ratio with positive ΔH（+231 mm）；elevated temperature，reduced humidity，and enhanced radiation in 2022 increased E/P ratio alongside decreased P and Rs，resulting in negative ΔH（-75 mm）；improved meteorological conditions in 2023 reduced E/P ratio and restored hydrothermal conditions，driving positive ΔH（+350. 6 mm）. This study provides crucial insights into unique hydrological mechanisms of monsoon-influenced lakes，supports ecological security barrier construction for the "Asian Water Tower"，and promotes sustainable development on the Qinghai-Xizang Plateau.