Exploring the potential value of satellite remote sensing to monitor chlorophyll-a for U.S. lakes and reservoirs.
Assessment of chlorophyll-a, an algal pigment, typically measured by field and laboratory in situ analyses, is used to estimate algal abundance and trophic status in lakes and reservoirs. In situ-based monitoring programs can be expensive, may not be spatially and temporally comprehensive and results may not be available in the timeframe needed to make some management decisions. Satellite remotely sensed chlorophyll-a offers the potential for more geographically and temporally dense data collection to support estimates when used to augment in situ measures. The annual potential avoided costs associated with increasing the availability of remotely sensed chlorophyll-a values were estimated at $3.2 to $24 million depending upon the satellite program used. We also compared sociodemographic characteristics of the regions (both public and private lands) covered by both remote sensing and in situ data to check for any systematic differences across areas that have monitoring data. This analysis underscores the importance of continued support for both field-based in situ monitoring and satellite sensor programs that provide complementary information to water quality managers, given increased challenges associated with eutrophication, nuisance, and harmful algal bloom events.