Jet Propulsion Laboratory, California Institute of Technology , Pasadena, California 91109, United States.
United States Geological Survey, Sacramento, California 95819, United States.
Environ Sci Technol. 2016 Jan 19;50(2):573-83. doi: 10.1021/acs.est.5b03518. Epub 2015 Dec 28.
The San Francisco Bay-Delta Estuary watershed is a major source of freshwater for California and a profoundly human-impacted environment. The water quality monitoring that is critical to the management of this important water resource and ecosystem relies primarily on a system of fixed water-quality monitoring stations, but the limited spatial coverage often hinders understanding. Here, we show how the latest technology in visible/near-infrared imaging spectroscopy can facilitate water quality monitoring in this highly dynamic and heterogeneous system by enabling simultaneous depictions of several water quality indicators at very high spatial resolution. The airborne portable remote imaging spectrometer (PRISM) was used to derive high-spatial-resolution (2.6 × 2.6 m) distributions of turbidity, and dissolved organic carbon (DOC) and chlorophyll-a concentrations in a wetland-influenced region of this estuary. A filter-passing methylmercury vs DOC relationship was also developed using in situ samples and enabled the high-spatial-resolution depiction of surface methylmercury concentrations in this area. The results illustrate how high-resolution imaging spectroscopy can inform management and policy development in important inland and estuarine water bodies by facilitating the detection of point- and nonpoint-source pollution, and by providing data to help assess the complex impacts of wetland restoration and climate change on water quality and ecosystem productivity.
旧金山湾-三角洲河口流域是加利福尼亚州淡水的主要来源，也是一个深受人类影响的环境。水质监测对于管理这一重要水资源和生态系统至关重要，主要依赖于固定水质监测站系统，但有限的空间覆盖范围常常阻碍了人们的理解。在这里，我们展示了可见/近红外成像光谱学的最新技术如何通过能够以非常高的空间分辨率同时描绘几个水质指标，从而促进这个高度动态和异质系统中的水质监测。机载便携式远程成像光谱仪 (PRISM) 用于在该河口受湿地影响的地区得出高空间分辨率 (2.6×2.6 m) 的浊度、溶解有机碳 (DOC) 和叶绿素-a 浓度分布。还使用原位样本开发了滤过性甲基汞与 DOC 的关系，从而能够以高空间分辨率描绘该区域的表面甲基汞浓度。结果表明，高分辨率成像光谱学如何通过检测点源和非点源污染，以及提供数据帮助评估湿地恢复和气候变化对水质和生态系统生产力的复杂影响，为重要的内陆和河口水体的管理和政策制定提供信息。
