Geophysics to Mitigate Brownification of Lake Water – First Results

Brownification of surface waters, or browning, describes the increase of water colour in water systems. This phenomenon occurs due to an increase in dissolved organic carbon and iron concentrations. Browning is a major environmental concern, as it has negative effects on both water quality, and therewith the drinking water production, and the health of aquatic ecosystems. The aim of two research projects is to find mitigation measures to decrease the browning but also to monitor these changes. That is planned in the surrounding of Lake Bolmen, located in the South of Sweden. One part of the project is geophysical investigations. With the help of the direct current induced polarization (DCIP) and ground penetrating radar (GPR) methods, we want to characterise the underground, investigate the connection between surface water and groundwater and find a link between the electrical IP properties and the browning. During the first reconnaissance measurements we observed a connection between the chargeability and the browning of the sampled water. In the next step, a DCIP monitoring system will be set up to observe and follow the changes over several seasonal periods.