(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 investigated the thermal properties of Tibetan lakes during the ice-covered season. They revealed that an extremely large amount of solar radiation penetrated the highly transparent ice cover. As a result, lakes fully mix under ice and get heated up to >6°C. The accumulated heat makes a crucial contribution to ice cover melt.
Transformation of organic micropollutants along hyporheic flow in bedforms of river-simulating flumes
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.
Misbalance of thyroid hormones after two weeks of exposure to artificial light at night in Eurasian perch Perca fluviatilis
In a lab study it was tested if light pollution affects thyroid hormones in Eurasian perch. The results show first signs of endocrine disruption in thyroid metabolism after a relatively short exposure of two weeks under high-intensity streetlight conditions. Misbalanced thyroidal status can have serious implications for metabolic rates as well as developmental and reproductive processes.
Using isotopes to understand landscape‐scale connectivity in a groundwater‐dominated, lowland catchment under drought conditions
The authors integrated hydrometric and isotope data to understand how droughts affect ecohydrological partitioning, hydrological connectivity and streamflow generation at the catchment scale. Groundwater recharge was lower under forest than grassland and enhanced in restored wetlands. Complex patterns of connectivity affect in-stream solute transport and interactions between land- and riverscapes.
Quantifying the effects of land use and model scale on water partitioning and water ages using tracer-aided ecohydrological models
The authors used the IGB model EcH2O-iso with isotope tracers to quantify how different vegetation communities in lowland German catchments partition rainfall into evapotranspiration and groundwater recharge. This showed that forests account for greater water losses to the atmosphere and reduced recharge. Future losses under climate change can be optimised by species selection and management.