- Programme area:Dimensions of Complexity of Aquatic Systems
Integrating Tracers and Soft Data Into Multi-Criteria Calibration: Implications From Distributed Modeling in a Riparian Wetland
This study aimed to unravel the heterogenous spatio-temporal patterns of hydrological processes in a riparian wetland over 2 years. The work provided insights into ecohydrological wetland functioning, but also revealed potential equifinality in process-based models even with abundant data for calibration, and solutions based on the integration of water isotopes and soft data into modelling.
Time Series of Electrical Conductivity Fluctuations Give Insights Into Long-Term Solute Transport Dynamics of an Urban Stream
A solute transport model was applied to diurnal electrical conductivity fluctuations in a river to obtain long-term time series of transport metrics. The study showed that differences in transport metrics occur in adjacent river reaches and that mowing of macrophytes can increase the transient storage area.
Combined Surface-Subsurface Stream Restoration Structures Can Optimize Hyporheic Attenuation of Stream Water Contaminants
A numerical model was used to evaluate engineered stream restoration structures and how to maximise their impact on hyporheic contaminant attenuation. Combined surface-subsurface structures were able to simultaneously increase hyporheic fluxes and transit times, providing conditions for contaminant attenuation that were many times more effective than surface or subsurface structures alone.
Environmental Science & Technology - 57(2023)38, 14101-14492
Predicting PFAS and Hydrophilic Trace Organic Contaminant Transport in Black Carbon-Amended Engineered Media Filters for Improved Stormwater Runoff Treatment
Hydrophilic organic contaminants and per- and polyfluoroalkyl substances (PFAS) are difficult to remove from stormwater runoff. A contaminant transport model was validated to better estimate the removal of contaminants in stormwater filtration systems.
Improved understanding of vegetation dynamics and wetland ecohydrology via monthly UAV-based classification
The authors conducted monthly UAV flights for 2 years in a riparian wetland in Germany. Such multi-flight-based classification outperformed single-flight-based ones, providing a picture of vegetation community evolution. Apart from contributing to an evidence base for wetland management, such multi-flight UAV vegetation mapping could provide fundamental insights into their landscape ecohydrology.
As the hyporheic zone of rivers can be very heterogeneous already at cm-scales, the authors developed an experimental setup to preset short and shallow hyporheic flow paths in the field and to sample pore water. In this experimental setup, the authors were able to study the attenuation of 18 different trace organic compounds wherein the majority were attenuated within the short oxic sections.
Using seasonal, large scale synoptic sampling of stable water isotopes and tritium along the Spree allowed to assess water cycling, storage and losses. The Spree is heavily regulated and drought-sensitive due to high evapotranspiration losses. Such insights are important to adjust water management strategies.
Quantifying changes and trends of NO3 concentrations and concentration-discharge relationships in a complex, heavily managed, drought-sensitive river system
Long-term stream nitrate nitrogen concentrations and concentration-discharge were investigated along the Spree revealing significant heterogeneity in both variables. The upstream parts and winter seasons showed the most serious pollution. Concentrations and relationships are also likely to respond strongly to future droughts, leading to challenges for future land and water management.
This study investigated the mobilisation and transport of particle-associated organic contaminants and their cytotoxicity in a river during storm events. Cytotoxicity determined in cell-based bioassays correlated linearly with total suspended solids concentration in a river, demonstrating that particle-associated contaminant mixtures can strongly affect river water quality during rain events.
The study investigated the impact of streamwater flow velocities and the resulting bedform migration on the CO2 production in streambeds. State-of-the-art 2-dimensional imaging techniques reveal the CO2 distribution in the streambed, an increasing CO2 production in the upper sediment and a decreasing hydrological exchange with deeper sediment layers, with increasing flow velocities.