Articles | Volume 27, issue 1
https://doi.org/10.5194/hess-27-303-2023
https://doi.org/10.5194/hess-27-303-2023
Research article
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13 Jan 2023
Research article | Highlight paper |  | 13 Jan 2023

Droughts can reduce the nitrogen retention capacity of catchments

Carolin Winter, Tam V. Nguyen, Andreas Musolff, Stefanie R. Lutz, Michael Rode, Rohini Kumar, and Jan H. Fleckenstein

Data sets

Index of /climate_environment/CDC/grids_germany/daily/ DWD - Deutscher Wetterdienst https://opendata.dwd.de/climate_environment/CDC/grids_germany/daily/

Model code and software

mHM-SAS model (V2.0.0) T. V. Nguyen https://doi.org/10.5281/zenodo.7228149

mHM-Nitrate X. Yang https://git.ufz.de/yangx/mHM-Nitrate

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Executive editor
Understanding how catchments respond to change is a central theme of the work of many hydrologists around the world, however, it is fair to say that the vast majority of these studies have focused on water quantity. This study is unique in that it represents a very detailed treatment of how water quality changes due to drought, which is a topic that is becoming ever so important with the rapid changes happening in warming climate for many regions of the world. The authors very cleverly combine both complex models and data-driven analyses to elucidate the effects of extreme drought on river water quality.
Short summary
The increasing frequency of severe and prolonged droughts threatens our freshwater resources. While we understand drought impacts on water quantity, its effects on water quality remain largely unknown. Here, we studied the impact of the unprecedented 2018–2019 drought in Central Europe on nitrate export in a heterogeneous mesoscale catchment in Germany. We show that severe drought can reduce a catchment's capacity to retain nitrogen, intensifying the internal pollution and export of nitrate.