Climate change-induced higher water temperature is increasing the risk of algal blooms (ABs) in eutrophic water bodies. However, it is not well known how and to what extent warming affects ABs risk. In this work, with simple data input (satellite product, lake surface observation, and climate) and method structure (ensemble learning, statistical downscaling, and hierarchical clustering), a systematic lake surface water temperature (LSWT) and ABs risk evaluation system are constructed and applied in a typical eutrophic freshwater lake. The main results are as follows: 1. The warming rate of LSWT and air temperature from 2000 to 2023 reached 0.21 °C/10a and 0.30 °C/10a respectively, resulting in an extended ABs risk in the historical period. 2. The Nash–Sutcliffe efficiency between climate and LSWT reached 0.89, and LSWT showed a significant (p < 0.05) positive correlation with algal density. 3. The escalation of ABs risks mainly spread to spring and autumn in the forthcoming future, the adverse effect of high emission scenarios will evidently emerge in the mid-21st century. Policymakers and catchment managers should be cautious of lake warming and develop countermeasures in advance.

中文翻译：

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气候变暖下高山富营养化湖泊地表水温度诱发藻华风险的动态分析——来自滇池的见解


气候变化引起的水温升高正在增加富营养化水体中藻华 （AB） 的风险。然而，目前尚不清楚变暖如何以及在多大程度上影响 ABs 风险。在这项工作中，通过简单的数据输入 （卫星产品、湖面观测和气候） 和方法结构 （集成学习、统计降尺度和分层聚类），构建了系统的湖泊表层水温度 （LSWT） 和 ABs 风险评估系统，并将其应用于典型的富营养化淡水湖。主要结果如下：1. 2000—2023 年 LSWT 的升温速率和气温分别达到 0.21 °C/10a 和 0.30 °C/10a，导致历史时期 ABs 风险延长。2. 气候与 LSWT 之间的 Nash-Sutcliffe 效率达到 0.89，LSWT 与藻类密度呈显著 （p < 0.05） 正相关。3. ABs风险升级主要蔓延到即将到来的春季和秋季，高排放情景的不利影响将在21世纪中叶明显显现。政策制定者和流域管理者应谨慎对待湖泊变暖，并提前制定对策。