Estuaries worldwide are experiencing stress due to increased droughts, which often prompt intervention by environmental managers and government agencies. Effective management of water resources in estuarine systems can be enhanced by new technologies and methodologies to support decision-making processes. Here, we evaluate the use of high-frequency, high-resolution satellite remote sensing within two management-relevant case studies in the San Francisco Estuary and the Sacramento–San Joaquin River Delta. We used a remote sensing-derived time series of turbidity maps to (1) identify favorable turbidity conditions for the endangered fish species, delta smelt (Hypomesus transpacificus), during the height of the great California drought in the dry season of 2015, and (2) evaluate changes in turbidity following the installation of an emergency saltwater intrusion barrier. The mapping results indicate several persistent areas of turbidity refugia throughout the summer in the north and west Delta; however, there was infrequent connectivity. A comparison of images captured during ebb tides before and after barrier installation showed a mean increase of 6.6 Nephelometric Turbidity Units (NTU) in the San Joaquin River and 4 NTU in Fisherman’s Cut. Our assessment of the barrier supports previous findings, which used field samples to conclude barrier installation may have resulted in increased turbidity near the barrier and enhances these findings by providing spatial context.

中文翻译：

---

使用卫星遥感评估鱼类栖息地和紧急干旱屏障对河口浊度的影响

由于干旱加剧，世界各地的河口正面临压力，这通常会促使环境管理者和政府机构进行干预。支持决策过程的新技术和方法可以加强河口系统水资源的有效管理。在这里，我们评估了在旧金山河口和萨克拉门托 - 圣华金河三角洲的两个与管理相关的案例研究中使用高频、高分辨率卫星遥感。我们使用遥感衍生的浊度图时间序列来 (1) 确定对濒危鱼类 delta smelt ( Hypomesus transpacificus ) 有利的浊度条件)，在 2015 年旱季加州大旱的高峰期，以及 (2) 评估安装紧急盐水入侵屏障后的浊度变化。绘图结果表明整个夏季在三角洲北部和西部有几个持续的浊度避难所；然而，很少有连接。在安装屏障之前和之后的退潮期间拍摄的图像的比较显示，圣华金河平均增加了 6.6 个浊度计浊度单位 (NTU)，而渔人区则增加了 4 个 NTU。我们对屏障的评估支持了先前的发现，该研究使用现场样本来得出结论，屏障安装可能导致屏障附近的浊度增加，并通过提供空间背景来增强这些发现。