Groundwater-Surface Water Interactions
Our research addresses ecohydrological processes at interfaces between aquifers and surface water bodies. We investigate hydrological transport processes, biogeochemical turnover and the close coupling of these processes at the interface. We conduct field investigations, lab and modelling studies. A focus is on the development and application of innovative measurement techniques.
We study three different types of groundwater-surface water interfaces:
- Some research is on so-called hyporheic zones (streambed, i.e. interface between stream and aquifer). We consider the hyporheic zone as a natural, hydro-dynamically driven bioreactor responsible for the impressive self-purification capacity of streams regarding nutrients (phosphorus, nitrogen, and carbon) and organic trace compounds (e.g., pharmaceuticals).
- Other research of our multidisciplinary group focuses on lacustrine groundwater discharge, i. e. the aquifer-lake interface. Surprisingly, groundwater has usually been neglected in water and nutrient budgets of lakes until recently. Even world-wide there is very little research on this topic. We could show the large relevance of groundwater exfiltration and groundwater-borne nutrient transport for lake eutrophication and other ecological challenges.
- Further research focuses on burrowing macrozoobenthos (chironomid larvae) in lake sediments (interface between lake and pore water). These small ecosystem engineers alter not only the local hydrology and biogeochemistry but have even severe impacts on entire ecosystems.