Selected publications

Understanding organizational principles of hyporheic exchange flow and biogeochemical cycling in landscapes is key for generalizing process knowledge.

At its deepest point, Lake Burgsee has one of the highest methane concentrations ever measured in a natural freshwater lake.

A hybrid model which combines a classical 1D lake model with data-driven machine learning was used to predict changes in deepwater oxygen concentrations under varying climatic conditions and nutrient concentrations. The model predicted deepwater oxygen concentrations of Lake Geneva more precisely than a classical approach. Increasing air temperatures have similar effects as phosphorus inputs.

In course of measuring campaigns, the spatial and temporal dynamics of water isotopes in northeastern German lakes were evaluated. The data will serve as basis for further studies, for example with respect to connectivity of lakes and biochemical processes in macrophytes.

The authors monitored stable isotopes in-situ at high resolution in soil and plant water at an urban green space to understand the ecohydrological functioning of the Critical Zone, i.e., the thin, dynamic, life-sustaining skin of the Earth that extends from the canopy top to the active groundwater. At the end of the growing season deeper than upper soil water was used for plant water uptake.

Radon in surface water is mostly used to localise and quantify groundwater discharge. The study presents the opposite approach and use radon to estimate travel times of infiltrated surface water in the aquifer. The spatial heterogeneity of radon production rates complicates this approach, but the problems can be overcome by additionally considering temperature and hydraulic heads.

Using field-experimental data, crop N uptake responses to fertilizer management were parsimoniously conceptualized and integrated into a catchment diffuse-N model. The improved catchment modeling further facilitated integration with agricultural budget-based assessments.

The authors used isotope tracers and water quality measurements, hydrometric and climatic data to investigate seasonal changes in water sources in the River Erpe. Downstream, flows were dominated by effluent from a large wastewater treatment plant, especially in summer. They gained new insights into how lowland, peri-urban catchments with complex land use function hydrologically.