A massive algae bloom can be detected in the Oder River using satellite data. Experts from Brockmann Consult (a company for environmental data analysis and software located in Hamburg) have processed satellite data from the European Copernicus satellite Sentinel 2 in close cooperation with the Leibniz Institute of Freshwater Ecology and Inland Fisheries (IGB) and the AG Modelling Methods in Remote Sensing at the University of Leipzig and calculated chlorophyll concentrations, which serve as indicators of algal blooms.
© Brockmann Consult | The graphic may be used for journalistic as well as non-commercial purposes if the copyright is mentioned.
The Sentinel 2 satellite carries an optical sensor that can be used to determine water color and infer which color-giving substances are in the water. Color-providing pigments such as the chlorophyll in algae change the incident sunlight, and the sensor onboard of the satellite can detect this change in the light. This means that also unusual high concentrations of algae can be detected.
In this initial analysis, three selected time periods were examined. The graph shows three profiles of chlorophyll concentrations in the Odra River in late July, early August and mid-August. The yellowish colors indicate the particularly high chlorophyll concentrations. At the end of July, the concentration of the entire river course is at about a medium level with a slight increase in the southern section of the river around the town of Opode. In early August, a jump in chlorophyll concentration is seen at the level of Wroclaw, and 10 to 12 days later the algal bloom has moved further downstream like a wave and spread to a larger area of the Odra River.
The satellite data have great potential to help further clarify the Odra disaster. The new results will help to better understand the ongoing toxic prymnesium algal bloom and to narrow down its origin in space and time. For this purpose, aquatic ecological monitoring data and water samples are combined with satellite data, which are also available from the time of the onset of the environmental disaster. These analyses are to be continued in the coming weeks.
