(Dept. 1) Ecohydrology
Interactions between green (in terrestrial systems) and blue water (lakes, rivers, and subsurface aquifers) create complex waterscapes. These constitute habitats for biota and are reactive transport media for abiotic components, coupled at multiple spatio-temporal scales. What unites us at the Department of Ecohydrology is the aim to improve understanding of mechanisms and processes of these connected land- and waterscapes in natural, rural and urban environments. Consequently, most of our current research projects focus on at least one of the following three core topics: landscape-waterscape interactions, urban ecohydrology, or abiotic-biotic coupling.
In our research, we integrate different modelling approaches with data collected in field studies, in large-scale field manipulation studies as well as in laboratory experiments. By using tracers like stable isotopes, natural conservative geogenic ions, nutrients or organic matter, we identify and quantify coupled hydrological and biogeochemical processes. Of special interest are anthropogenic influenced and disturbed ecosystems, in particular heavily modified urban systems. To appropriately address our research aim, we combine our expertise across research disciplines, such as environmental engineering, hydrology, ecology, and geography.
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.
Catchment functioning under prolonged drought stress: Tracer‐aided ecohydrological modeling in an intensively managed agricultural catchment
The authors investigated the effects of recent years’ droughts on ecohydrological processes in an agricultural catchment using an isotope-aided model (EcH2O-iso). Stream discharge could be sustained by deep, old groundwater, while transpiration fluxes were heavily reduced by drought stress. Crucially, tracer-based water age estimates can be used as potential indicators of drought impacts.
67 scientists reviewed 1700 peer-reviewed articles on soil-erosion modelling. The study addresses the relevance of regions, models, and model validation and includes the open-source database.
Simultaneous attenuation of trace organics and change in organic matter composition in the hyporheic zone of urban streams
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.
Stable isotopes of water reveal differences in plant – soil water relationships across northern environments
The authors compared stable isotopes of water in the plant stem (xylem) and in the soil over a complete growing season at five northern experimental sites to understand where plants get their water from and what the temporal dynamics are of such root water uptake. This paper was a main finding of an ERC Grant.