IES use satellite data for lake quality assessment

Researchers from the Institute for Environmental Solutions (IES) develop satellite data-based tool that will provide a general overview of water quality in Latvian lakes.

The importance of inland water bodies including lakes has never been greater. They help to regulate the carbon cycle, thus impacting the climate. Moreover, lakes are economically important – they provide drinking water, fishing and recreation opportunities. Therefore, the monitoring of lakes and water quality has become a global concern. Responding to it, European Union (EU) implements the Water Framework Directive. Under the framework, EU wants to reach good water quality in all lakes in Europe that are larger than 0.5 sq. km. Due to limited resources, only a small part of Latvian lakes can be monitored every year. To contribute and fill the gaps of lake monitoring in Latvia, more time and other resources have to be invested, or new, improved automated methods should be developed.

IES’s leading researcher Dr. Dainis Jakovels explains: “There are more than 2200 lakes in Latvia. Standard methods for lake water quality monitoring are water sampling campaigns – researchers go to lake, take water samples, and analyse them in laboratory. This approach gives a detailed insight about lake condition, but it is expensive and time-consuming process. Therefore, lakes in Latvia that are larger than 0.5  sq. km are assessed less than once a year.”

Remote sensing technologies and data is a rich source of information that can help to optimize the lake quality assessment. By using Copernicus Earth observation satellite data, IES’s researchers develop automated tool for remote lake monitoring. Most important information obtained from satellite data is chlorophyll concentration that is an indicator of lake blooming.

“Sentinel-2 satellite fly over Latvia once every five days. If there are no clouds that interferes, we can assess the current situation in lakes. By using satellite data water quality status in lakes can be updated every month. We have created an automated tool for spectral satellite data processing and water quality assessment. We also plan a further development of this approach,” Dr. Dainis Jakovels highlighting the benefits of the tool development.

The tool is developed as a supplementary support for existing lake monitoring methods. It will help to understand the overall status of water quality – which lakes are in a bad shape and require deeper situation analysis. “Particularly, noteworthy value of this tool is the possibility to notice the changes of lake water quality at an early stage. That makes it easier to find the cause and solutions,” explains Dr. Dainis Jakovels.

The first prototype of this tool is developed as part of the project “Sentinel-2 service for regular water quality monitoring in lakes” (SentiLake). This project is financed by the Ministry of Education and Science of the Republic of Latvia as part of European Space Agency programme “The Plan for European Cooperating States” (PECS).

Read more about this project here.