USDA Forest Service

Pacific Southwest Research Station

Pacific Southwest
Research Station

800 Buchanan Street
Albany, CA 94710-0011
(510) 883-8830
United States Department of Agriculture Forest Service. USDA logo which links to the department's national site. Forest Service logo which links to the agency's national site.

Monitoring past, present, and future water quality using remote sensing

Principal Investigators:
Geoff Schladow, University of California-Davis
Simon Hook, NASA Jet Propulsion Laboratory

Proposal [pdf]

Final Report [pdf]

Summary of Findings [pdf]

Please contact Dr. Geoff Schladow with questions regarding the report.

Project Summary

The intent of this project was to demonstrate the use of remote sensing for measuring water quality parameters at Lake Tahoe. One of the major benefits of this approach would be that a whole-lake view of water quality changes would be possible, even extending into the nearshore where discrete sources of pollutants could be identified. Linked to this was the possibility that through using archived satellite data, long-term trends in other parts of the lake (beyond the two sites currently monitored by University of California-Davis) would be feasible. The system capitalized on the local infrastructure developed by NASA and UC Davis, the long-term dataset that was collected by UC Davis, and the numerous freely available satellite datasets.

Through this study a semi-automated system was developed to utilize remotely-sensed data and field measurement data to quantify water clarity and near-surface chlorophyll a concentration measurements over the entire lake. The system was based on the use of MODIS satellite data (1 km, 500 m, and 250 m) that are available several times per day for the period 2002 – 2010. These data were used to create maps of water clarity and chlorophyll a which extend sufficiently close to the shoreline to assess the impacts and fate of key point and non-point pollutant sources.