The Water Framework Directive requires European states to monitor the ecological quality of their lakes. Detailed information on the composition and abundance of biological groups such as aquatic plants (macrophytes) and phytoplankton (including chlorophyll a ) must be expressed as an ecological quality ratio (EQR), ranging from 1 (close to reference status) to 0 (bad status). Effort is often focused on gathering this detailed information on selected lakes at the expense of more synoptic approaches that could capture a more holistic assessment of a catchment’s water quality. This could be rectified if remote sensing can provide predictions of ecological quality for unmonitored lakes. We found that data from Sentinel-2 satellites, based on regression model outputs of observed vs estimated results, successfully predicted the macrophyte EQR ( R 2 = 0.77) and the maximum lake depth that macrophytes colonised to ( R 2 = 0.80) but average chlorophyll a was less well predicted ( R 2 = 0.66). Predictions for a test catchment indicated that results were within one ecological assessment class width of measured values for macrophytes. This approach can potentially estimate status for unmonitored lakes in Ireland, be integrated with results on monitored lakes and used to direct resources where needed at national and catchment scales.

中文翻译：

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Sentinel-2遥感影像对湖泊生态质量的估计

水框架指令要求欧洲国家监测其湖泊的生态质量。有关水生植物（大型植物）和浮游植物（包括叶绿素 a ）等生物群的组成和丰度的详细信息必须表示为生态质量比 (EQR)，范围从 1（接近参考状态）到 0（不良状态） ）。努力通常集中在收集有关选定湖泊的详细信息上，而牺牲了更多的天气方法，这些方法可以对流域水质进行更全面的评估。如果遥感可以为未受监控的湖泊提供生态质量预测，则可以纠正这种情况。我们发现来自 Sentinel-2 卫星的数据，基于观测结果与估计结果的回归模型输出，成功预测了大型植物 EQR (R 2 = 0. 77) 和大型植物定居的最大湖泊深度 (R 2 = 0.80)，但平均叶绿素 a 的预测不太好 (R 2 = 0.66)。对测试集水区的预测表明，结果在大型植物测量值的一个生态评估类别宽度内。这种方法可以潜在地估计爱尔兰未监测湖泊的状况，与监测湖泊的结果相结合，并用于在国家和流域规模需要的地方引导资源。