Selected publications

The scientist allowed sediments of a nutrient-rich lowland river to dry out over 9 weeks to study temporal changes of microbial activity, carbon dioxide and methane emissions, and of the fluxes of water-soluble organic carbon. They also simulated short rainfalls on the dried-up riverbed. The study shows, that after drying up and raining, rivers can release more carbon dioxide and methane.

The authors quantified heterogeneity of rivers and methods and how many small decisions in studies bias outcomes. They identified most representative, replicable, and accurate river metabolism approaches, and suggest best practices to improve value of and confidence in big data aggregation and long term monitoring including: adjust for drift, measure from the thalweg, use local over remote data.

Urban green space is of great importance for sustainable water management and heat reduction in cities. Using field measurements and a highly advanced ecohydrological model, researchers have investigated how water pathways differ depending on vegetation type. The result: trees potentially provide the strongest cooling effect, while grass promotes more groundwater recharge.

In recirculating flumes, the authors investigated the degradation of micropollutants from treated wastewater along specific subsurface flow paths in triangular bedforms. Shallow subsurface flow fields and small-scale heterogeneity of the microbial community are major controlling factors for the transformation of micropollutants in river sediments.

The authors investigated the co-evolution of plant xylem water and soil water stable isotopic compositions in a northern mixed forest, Canada. They showed that differences in timing and intensity of water use between deciduous and coniferous trees may account for inter-specific variations in xylem water isotopic composition providing insight into how they may respond to hydroclimatic change.

With a physically based model that couples flow and heat transport in hyporheic zones, the study provides insights into hyporheic responses to daily groundwater withdrawal and river temperature fluctuations. These interactions have impacts on temporal variability of hyporheic exchange, mean residence times and denitrification potential. Improved pumping schemes can restore ecosystem functions.

The authors used a coupled lake-atmosphere model to investigate the effect of the largest lake of China, the Qinghai, on the weather and climate conditions of the Tibetan Plateau. They found that the lake alters wind conditions and increases precipitation over the arid areas of the earth’s “third pole” Tibet but the effect is irregularly distributed spatially and temporally over the seasons.  

Wastewater still contains high amounts of trace organic compounds and organic matter after the wastewater treatment plant. These compounds are usually discharged to rivers with the treated water. The study shows that in the hyporheic zone of the river, i.e. the river sediment, degradation of trace organic compounds takes place simultaneously with a change in the composition of organic matter.