Articles | Volume 21, issue 15
https://doi.org/10.5194/bg-21-3537-2024
© Author(s) 2024. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
https://doi.org/10.5194/bg-21-3537-2024
© Author(s) 2024. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Research article
| 
08 Aug 2024
Research article |
| 08 Aug 2024
| 08 Aug 2024
From Iron Curtain to green belt: shift from heterotrophic to autotrophic nitrogen retention in the Elbe River over 35 years of passive restoration
Alexander Wachholz
CORRESPONDING AUTHOR
Department of Aquatic Ecosystem Analysis and Management, Helmholtz Centre for Environmental Research (UFZ), Magdeburg, Germany
James W. Jawitz
Soil and Water Sciences Department, University of Florida, Gainesville, FL, USA
Dietrich Borchardt
Department of Aquatic Ecosystem Analysis and Management, Helmholtz Centre for Environmental Research (UFZ), Magdeburg, Germany
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Earth Syst. Sci. Data Discuss., https://doi.org/10.5194/essd-2024-563, https://doi.org/10.5194/essd-2024-563, 2025
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Small lakes and ponds are provide many functions for the environment. Because of their size they are often not considered in scientific studies. We collected all the information on those lakes and ponds for Germany and combined it to a database. We described the ponds in detail, for example how deep they might by, how much water they can store or if they are connected to rivers. We found more than 260.000 lakes and ponds in Germany.
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Climate change is increasing low flows, yet how streams respond remains poorly understood. Using sensors in a German stream during the extreme 2018 drought, we found hotter water, more algae, and lower oxygen and nitrate levels. Daily oxygen swings intensified, and algae on the riverbed boosted gross primary productivity. Nitrate removal got more efficient. These changes highlight risks to water quality and ecosystems as droughts worsen, aiding efforts to protect rivers in a warming world.
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Small lakes and ponds are provide many functions for the environment. Because of their size they are often not considered in scientific studies. We collected all the information on those lakes and ponds for Germany and combined it to a database. We described the ponds in detail, for example how deep they might by, how much water they can store or if they are connected to rivers. We found more than 260.000 lakes and ponds in Germany.
Jingshui Huang, Dietrich Borchardt, and Michael Rode
Hydrol. Earth Syst. Sci., 26, 5817–5833, https://doi.org/10.5194/hess-26-5817-2022, https://doi.org/10.5194/hess-26-5817-2022, 2022
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In this study, we set up a water quality model using a 5-year paired high-frequency water quality dataset from a large agricultural stream. The simulations were compared with the 15 min interval measurements and showed very good fits. Based on these, we quantified the N uptake pathway rates and efficiencies at daily, seasonal, and yearly scales. This study offers an overarching understanding of N processing in large agricultural streams across different temporal scales.
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Preprint retracted
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We develop the catchment water quality assessment platform HiWaQ v1.0, which is compatible with multiple hydrological model structures. The nitrogen module (HiWaQ-N) and its coupling tests with two contrasting grid-based hydrological models demonstrate the robustness of the platform in estimating catchment N dynamics. With the unique design of the coupling flexibility, HiWaQ can leverage advancements in hydrological modelling and advance integrated catchment water quantity-quality assessments.
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The Budyko curve emerges globally from the behavior of multiple catchments. Single-parameter Budyko equations extrapolate the curve concept to individual catchments, interpreting curves and parameters as representing climatic and biophysical impacts on water availability, respectively. We tested these two key components theoretically and empirically, finding that catchments are not required to follow Budyko curves and usually do not, implying the parametric framework lacks predictive ability.
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Hydrol. Earth Syst. Sci., 25, 6173–6183, https://doi.org/10.5194/hess-25-6173-2021, https://doi.org/10.5194/hess-25-6173-2021, 2021
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Climate classification systems divide the Earth into zones of similar climates. We compared the within-zone hydroclimate similarity and zone shape complexity of a suite of climate classification systems, including new ones formed in this study. The most frequently used system had high similarity but high complexity. We propose the Water-Energy Clustering framework, which also had high similarity but lower complexity. This new system is therefore proposed for future hydroclimate assessments.
Nathan G. F. Reaver, David A. Kaplan, Harald Klammler, and James W. Jawitz
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The parametric Budyko equations contain a single parameter (n or w), interpreted as depending on biophysical features, however, these relationships have remained elusive. We analytically invert the parametric Budyko equations, expressing n and w only in terms of the mean values of potential (E0) and actual evapotranspiration (E) and precipitation (P). These expressions allow n and w to be explicitly related to biophysical features through the dependence of P, E0, and E on those same features.
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Short summary
Human activities are rivers' main source of nitrogen, causing eutrophication and other hazards. However, rivers can serve as a natural defense mechanism against this by retaining nitrogen. We show that the Elbe River retains more nitrogen during times of high pollution. With improvements in water quality, less nitrogen is retained. We explain this with changed algal and bacterial activities, which correspond to pollution and have many implications for the river and adjacent ecosystems.
Human activities are rivers' main source of nitrogen, causing eutrophication and other hazards....
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