The Minnesota LakeBrowser is an online interactive lake water quality monitoring tool with Landsat-derived classifications of lake clarity of more than 10,500 lakes measured nine times from 1975 – 2015. From 2017 onward we have utilized an automated imagery processing system to process all available Sentinel 2 imagery to measure clarity, chlorophyll, and CDOM regularly throughout the open water season (May – October). We plan to regularly update the LakeBrowser as resources and new data become available. The earlier data can be downloaded from the LakeBrowser and more recent data can be accessed in the University of Minnesota GEMS Informatics Exchange platform.

Screenshot of the LakeBrowser tool
Pixel level classification of chlorophyll of Lake Minnetonka and surrounding lakes, September 2021.

Typically, the LakeBrowser is used to find water clarity or quality information for particular Minnesota lakes. To do so, you can either zoom in and out of areas to locate the lake of interest or search lakes by lake name. Once you have found the lake, you can display maps by year of lake clarity, chlorophyll, and CDOM (and by month for recent years) along with percentile rankings within state, county, ecoregion, and watershed, and land cover maps and statistics for a 1,000-foot buffer area around the lake. Links to additional lake information from the Minnesota Pollution Control Agency (PCA) and Department of Natural Resources (DNR) are also available.

In the past year, the LakeBrowser capability/functionality has been transferred to ArcGIS Server and Leaflet, a newer and easier-to-use platform that improves search and display capabilities. New data for lake clarity, chlorophyll, and CDOM were added, along with additional enhancements, including maps and statistical analyses on distributions by ecoregion, watershed, and county, plus temporal trends. Selected data can be downloaded by users for additional analysis. 

Maps and graphs showing what can be measured with the LakeBrowser tool

Landsat data archived at the EROS Center since Landsat 1 was launched in 1972 enable us to retrospectively classify images and examine historical trends. This type of information helps resource managers target problem areas, enables systematic monitoring of inland lakes, and demonstrates the power of satellite remote sensing. With statewide lake water clarity and quality data available for more than a single time period, statistical summaries and analyses that compare conditions over time by ecoregion, watershed, and county can be generated.