This study utilizes satellite data to investigate water quality conditions in the San Francisco Estuary and its upstream delta, the Sacramento–San Joaquin River Delta. To do this, this study derives turbidity from the European Space Agency satellite Sentinel-2 acquired from September 2015 to June 2019 and conducts a rigorous validation with in situ measurements of turbidity from optical sensors at continuous monitoring stations. This validation includes 965 matchup comparisons between satellite and in situ sensor data across 22 stations, yielding R² = 0.63 and 0.75 for Nephelometric Turbidity Unit and Formazin Nephelometric Unit (FNU) stations, respectively. This study then applies remote sensing to evaluate patterns in turbidity during the Suisun Marsh Salinity Control Gates Action (“Gates action”), a pilot study designed to increase habitat access and quality for the endangered Delta Smelt. The basic strategy was to direct more freshwater into Suisun Marsh, creating more low salinity habitat that would then have higher (and more suitable) turbidity than upstream river channels. For all seven acquisitions considered from June 29 to September 27, 2018, turbidity conditions in Bays and Sloughs subregions were consistently higher (and more suitable) (26–47 FNU) than what was observed in the upstream River region (13–25 FNU). This overall pattern was observed when comparing images acquired during similar tidal stages and heights.

中文翻译：

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利用卫星遥感监测旧金山河口和萨克拉门托-圣华金三角洲的浊度

本研究利用卫星数据调查旧金山河口及其上游三角洲萨克拉门托-圣华金河三角洲的水质状况。为此，本研究从 2015 年 9 月至 2019 年 6 月获得的欧洲航天局卫星 Sentinel-2 中获取浊度，并通过连续监测站的光学传感器对浊度的原位测量进行严格验证。该验证包括 22 个站的卫星和原位传感器数据之间的 965 次匹配比较，得出R ² = 0.63 和 0.75 对于浊度单位和福尔马津浊度单位 (FNU) 站，分别。然后，本研究应用遥感来评估 Suisun Marsh 盐度控制盖茨行动（“盖茨行动”）期间的浊度模式，这是一项旨在增加濒临灭绝的 Delta Smelt 栖息地进入和质量的试点研究。基本策略是将更多的淡水引入绥孙沼泽，创造更多的低盐度栖息地，然后比上游河道具有更高（和更合适）的浊度。对于 2018 年 6 月 29 日至 9 月 27 日期间考虑的所有七次收购，Bays 和 Sloughs 次区域的浊度条件始终高于（并且更合适）（26-47 FNU），高于上游河流地区（13-25 FNU）观察到的情况.