水面耀斑是水体遥感影像上的重要污染信息，哨兵2号卫星多光谱成像仪Sentinel-2 MSI（Sentinel-2 Multispectral Imager）影像上耀斑现象十分普遍，严重影响了Sentinel-2 MSI数据在水体遥感领域的应用。本研究从实证角度出发，在5个典型研究区开展了耀斑分布提取、耀斑时空分布规律分析及耀斑形成原因的探究工作。本研究发展了基于UNet模型的水面耀斑提取算法，算法总体精度超过96%。基于提取结果开展了水面耀斑的时空分布规律研究，结果表明：Sentinel-2 MSI影像上水面耀斑具有显著的区域和时间分布规律，部分严重区域耀斑发生频率高达80%、每景影像上耀斑平均发生面积超过30%；水面耀斑的发生主要受太阳角度、观测角度、纬度、轨道位置的影响，而内陆小型水体受风速、气温等气象因子影响较小；通过改变成像时间、观测角度、成像方式可以有效降低耀斑发生的频率和强度。本文通过对Sentinel-2 MSI影像上水面耀斑现象的量化评估和实证分析，进一步验证了其形成机制，为耀斑物理模型的构建和后续卫星减弱水面耀斑的研究提供了数据支撑。

Water surface sun glint is a significant source of contamination in water remote sensing imagery. Sun glint phenomena are widespread in Sentinel-2 MSI images, severely limiting the application of Sentinel-2 MSI data in water remote sensing. From an empirical perspective, this study conducted sun glint distribution extraction, analysis of spatial–temporal patterns, and investigation into the causes of sun glint in five typical study areas. This study developed a water surface sun glint extraction algorithm based on the UNet model, with an overall accuracy exceeding 96%. Research on the spatiotemporal distribution patterns of water surface sun glint was conducted on the basis of the extraction results. Water surface sun glint in Sentinel-2 MSI imagery exhibits distinct regional and temporal distribution patterns. In some severely affected areas, the frequency of sun glint occurrence reaches up to 80%, with the average glint-affected area exceeding 30% per image. The occurrence of water surface sun glint is primarily influenced by solar angle, viewing angle, latitude, and orbital position, while inland small water bodies show minimal direct correlation with meteorological factors such as wind speed and air temperature. Adjusting imaging time, viewing angles, and imaging methods can effectively reduce the frequency and intensity of sun glint. On the basis of the quantitative evaluation and empirical analysis of water surface sun glint in Sentinel-2 MSI imagery, this study validates the formation mechanism of sun glint, providing data support for physical models and the mitigation of water surface sun glint in subsequent satellite missions.