Freshwater resources, vital for both environmental health and human survival, are increasingly under pressure. While attention often focuses on water availability, the quality of these resources is equally critical. Now, a growing body of work is demonstrating the potential of satellite-based monitoring to supplement traditional methods of assessing and protecting inland water quality.
For years, monitoring freshwater quality has relied heavily on collecting physical samples from rivers, lakes, and streams – a process that can be both time-consuming, and expensive. Satellite technology offers a complementary approach, providing the ability to regularly assess large areas, even across international borders, reducing the need for extensive on-the-ground infrastructure. The Copernicus program, a European initiative dedicated to Earth observation, is at the forefront of this effort, regularly collecting data on key indicators like chlorophyll levels, turbidity, and water visibility.
A recent research project, known as BIGFE (Border Initiative for German-Dutch Freshwater Ecosystems), has focused on bridging the gap between the availability of this satellite data and its practical application by state environmental authorities. Researchers at Humboldt University of Berlin (HU) led a work package dubbed “The Last Mile,” investigating how well-versed these authorities are in remote sensing technologies and identifying barriers to their wider adoption. Through surveys and workshops, the project team discovered a growing awareness of the possibilities offered by satellite data, but also identified areas where further support and guidance are needed.
The findings of BIGFE have been compiled into a practical guideline designed to help state environmental authorities integrate satellite remote sensing into their routine water monitoring programs. This guide addresses common questions about data interpretation, reliability, and the specific steps involved in utilizing satellite-derived information. It acknowledges that while terrestrial applications of remote sensing, such as monitoring forest health, are well-established, the use of satellite data for water quality monitoring is still relatively underdeveloped.
The project highlights the international nature of freshwater management. Many rivers and lakes cross geopolitical boundaries, necessitating a broad, collaborative approach to monitoring and protection. Satellite data, by its very nature, transcends these borders, providing a consistent and comprehensive view of water quality across entire watersheds. This represents particularly important for complying with policies like the EU’s Water Framework Directive, which requires regular assessment of the ecological status of freshwater bodies.
The Copernicus program provides data that can help decision-makers, water utility companies, and the public make informed decisions about water management. Specifically, satellites can measure parameters like chlorophyll-a concentration (an indicator of algal blooms), total suspended solids (a measure of water clarity), and Secchi disk depth (another measure of water visibility). NASA’s STREAM (Satellite-based Tool for Rapid Evaluation of Aquatic Environments) is another initiative utilizing satellite imagery to generate high-resolution water quality maps.
The BIGFE project, funded by the German Federal Ministry for Digital and Transport through the German Space Agency, involved collaboration between Humboldt University of Berlin, the Institute for Lake Research of the State Institute for the Environment in Baden-Württemberg, and the Saxon State Office for the Environment, Agriculture and Geology. The project ran from to .
The researchers emphasize that satellite remote sensing is not intended to replace traditional monitoring methods entirely, but rather to complement and enhance them. By providing a broader spatial and temporal perspective, satellite data can help prioritize areas for more intensive in-situ sampling, optimize monitoring efforts, and ultimately contribute to more effective water resource management.
Interested experts can obtain a printed copy of the application guide by emailing BIGFE-Hamburg@hu.hamburg.de. The guide is also available for download as a PDF: https://www.ufz.de/export/data/496/304462_BIGFE-Anwenderleitfaden-2025.pdf. Further information about the BIGFE project can be found on the Helmholtz Center for Environmental Research website: https://www.ufz.de/bigfe/.
As the demand for freshwater continues to grow, and the impacts of climate change become more pronounced, innovative monitoring approaches like satellite remote sensing will play an increasingly important role in ensuring the sustainable management of this precious resource.
