- Programme area:3) Dimensions of Complexity of Aquatic Systems
Ecohydrological resilience and the landscape water storage continuum in droughts
A better understanding of water storage dynamics at medium scales, i.e. areas between 10 and 100 square kilometres, could help to better predict and ensure the availability of water resources, even in times of climate change. To this end, the researchers here synthesised findings from several long-term studies and introduced the concept of ecohydrological resilience.
Persulfate activation by biochar and iron: Effect of chloride on formation of reactive species and transformation of N,N-diethyl-m-toluamide (DEET)
This study investigated the formation of reactive species during the activation of the chemical oxidant persulfate with biochar and iron in different water types for the removal of organic contaminants. The presence of organic matter and chloride altered the reactive species formed, emphasizing that the water matrix is a critical factor for the application of this oxidation process .
Mixtures of organic micropollutants exacerbated in vitro neurotoxicity of prymnesins and contributed to aquatic toxicity during a toxic algal bloom
This study investigated how organic micropollutants and the algal toxins prymnesins interact as mixtures in water extracts from the Oder River using neurotoxic effects on human nerve cells in vitro. The authors showed that prymnesins dominate the neurotoxic effects, but many of the detected organic micropollutants exacerbate the lethal effect of prymnesins.
Linking terrestrial biogeochemical processes and water ages to catchment water quality: A new Damköhler analysis based on coupled modeling of isotope tracers and nitrate dynamics
Catchment-scale nitrate dynamics involve complex coupling of hydrological transport and biogeochemical transformations, imposing challenges for source control of diffuse pollution. Coupled modeling of isotope tracers and nitrate dynamics revealed that upland arable areas impose pollution risks under drought while the river-connected lowlands are processing hotspots and more resilient to drought.
Unveiling nitrate origins in semiarid aquifers: A comparative analysis of Bayesian isotope mixing models using nitrate and boron isotopes and a Positive Matrix Factorization model
The authors identified the dominant sources of nitrate pollution and biogeochemical transformations in the semiarid region of the Meoqui-Delicias aquifer, Mexico, where the uncontrolled use of chemical fertilizers and manure lead to excessive nutrient input resulting in deterioration of groundwater quality. This provides an evidence base for policy-making to protect drinking water quality.
A desiccating saline lake bed is a significant source of anthropogenic greenhouse gas emissions
Desiccating salt lakes are an underappreciated source of greenhouse gases that could become even more relevant as a result of climate change. This study, examining greenhouse gas emissions from the drying lake bed of Great Salt Lake, Utah, calculates that 4.1 million tons of carbon dioxide and other greenhouse gases were released in 2020.
Temperatures and hypolimnetic oxygen in German lakes: Observations, future trends and adaptation potential
A study of oxygen and temperature trends in 46 German lakes showed that temperatures have risen mainly at the surface, but not in the deep water. This led to increased stratification and lower oxygen concentrations. Scenarios showed that these effects of climate change on oxygen content could be compensated by reducing nutrients.
Flow Rate and Kinetics of Trace Organic Contaminants Removal in Black Carbon-Amended Engineered Media Filters for Improved Stormwater Runoff Treatment
Urban stormwater runoff is an untapped source of freshwater for many water-scarce regions, but improved stormwater treatment is needed for safe use and to protect human and aquatic health. This work provides insights into the kinetic limitations of contaminant removal within biochar and regenerated activated carbon filters and discusses implications for stormwater filter design and operation.
Long-term drought effects on landscape water storage and recovery under contrasting landuses
Process-based, tracer-aided ecohydrological modelling and ML were combined to estimate the effects of long-term drought on water fluxes/storage in the Spree catchment. The recent major droughts resulted in declines in groundwater recharge (>40 %), evapotranspiration (up to 16 %) and soil moisture (up to 6 %). Groundwater levels may not recover in 15 years if precipitation anomalies persist.
Hydroclimatic non-stationarity drives stream hydrochemistry dynamics through controls on catchment connectivity and water ages
Long-term water chemistry and isotope data were integrated to investigate hydrological function and water ages in the Scottish Girnock Burn catchment with an Atlantic Salmon population. Changing climatic conditions and stream flow responses continue to cause changes in water quality and ecosystem services with an increase in low flows, derived from older groundwater with more alkaline chemistry.