作者：Ling, C., Wu, H., Wu, H., Zhang, Y., Wang, M. & He, S.

Lake deoxygenation, driven by climatic warming and anthropogenic influences, threatens aquatic ecosystems. As climate change intensifies, compound dry-hot events (CDHEs) are projected to exert growing pressure on lake oxygen dynamics, yet their role in driving deoxygenation remains unclear. Using multisource data sets and machine learning, we analyzed surface dissolved oxygen (DO) dynamics and the percent saturation (DO%sat) in 11,571 Chinese lakes from 2000 to 2020, quantified CDHE impacts, and projected future trajectories under Shared Socioeconomic Pathway (SSP) scenarios. We found widespread and continuous deoxygenation in China, with 52.2% of lakes showing significant declines (average of -0.12 mg/L/decade and -1.28%/decade for DO and DO%sat, respectively), most pronounced on the Tibetan Plateau and Mongolian Lakes. Intensifying CDHEs, particularly in arid or semiarid regions, increasingly amplified lake surface deoxygenation through their duration and severity. Projections indicate nationwide declines of DO (0.73-1.01 mg/L) and DO%sat (4.08-10.73%) by 2099 under all SSP scenarios, with Tibetan Plateau lakes showing the most severe deoxygenation. From a long-term perspective, air temperature and precipitation dominate the climatic drivers of deoxygenation for low-elevation plain lakes, while wind speed and air pressure are key for high-altitude and semiarid region lakes. Our findings highlight the urgency of incorporating climate extremes into lake management water-quality planning to safeguard freshwater resources.

在气候变暖和人为影响的驱动下，湖泊脱氧正威胁着水生生态系统。随着气候变化加剧，复合型干热事件（CDHEs）预计会对湖泊氧气动态产生越来越大的压力，但其在推动脱氧过程中的作用仍不明确。借助多源数据集和机器学习，分析了 2000 年至 2020 年间中国 11571 个湖泊的表层溶解氧（DO）动态及饱和度百分比（DO% sat），量化了复合型干热事件的影响，并在共享社会经济路径（SSP）情景下预测了未来趋势。发现中国存在广泛且持续的脱氧现象，52.2% 的湖泊呈现显著下降趋势（溶解氧和溶解氧饱和度百分比的平均下降速率分别为 - 0.12 毫克 / 升 / 十年和 - 1.28%/ 十年），其中青藏高原和蒙古湖泊的下降最为明显。日益加剧的复合型干热事件，尤其是在干旱或半干旱地区，通过其持续时间和严重程度，不断加剧湖泊表层的脱氧。预测表明，到 2099 年，在所有共享社会经济路径情景下，全国范围内的溶解氧（下降 0.73-1.01 毫克 / 升）和溶解氧饱和度百分比（下降 4.08-10.73%）都将下降，青藏高原的湖泊脱氧最为严重。从长期来看，气温和降水是低海拔平原湖泊脱氧的主要气候驱动因素，而风速和气压则是高海拔及半干旱地区湖泊脱氧的关键驱动因素。我们的研究结果强调，在湖泊管理和水质规划中纳入极端气候因素以保护淡水资源的紧迫性。

（来源：Environmental Science & Technology 2026 DOI: 10.1021/acs.est.5c18168）