Publication Details

Category Text Publication
Reference Category Journals
DOI 10.5194/hess-27-303-2023
Licence creative commons licence
Title (Primary) Droughts can reduce the nitrogen retention capacity of catchments
Author Winter, C.; Nguyen, V.T. ORCID logo ; Musolff, A.; Lutz, S.R.; Rode, M.; Kumar, R. ORCID logo ; Fleckenstein, J.H.
Source Titel Hydrology and Earth System Sciences
Year 2023
Department ASAM; CHS; HDG
Volume 27
Issue 1
Page From 303
Page To 318
Language englisch
Topic T5 Future Landscapes
Data and Software links
UFZ wide themes TERENO;
Abstract In 2018–2019, Central Europe experienced an unprecedented 2-year drought with severe impacts on society and ecosystems. In this study, we analyzed the impact of this drought on water quality by comparing long-term (1997–2017) nitrate export with 2018–2019 export in a heterogeneous mesoscale catchment. We combined data-driven analysis with process-based modeling to analyze nitrogen retention and the underlying mechanisms in the soils and during subsurface transport. We found a drought-induced shift in concentration–discharge relationships, reflecting exceptionally low riverine nitrate concentrations during dry periods and exceptionally high concentrations during subsequent wet periods. Nitrate loads were up to 73 % higher compared to the long-term load–discharge relationship. Model simulations confirmed that this increase was driven by decreased denitrification and plant uptake and subsequent flushing of accumulated nitrogen during rewetting. Fast transit times (<2 months) during wet periods in the upstream sub-catchments enabled a fast water quality response to drought. In contrast, longer transit times downstream (>20 years) inhibited a fast response but potentially contribute to a long-term drought legacy. Overall, our study reveals that severe droughts, which are predicted to become more frequent across Europe, can reduce the nitrogen retention capacity of catchments, thereby intensifying nitrate pollution and threatening water quality.
Persistent UFZ Identifier
Winter, C., Nguyen, V.T., Musolff, A., Lutz, S.R., Rode, M., Kumar, R., Fleckenstein, J.H. (2023):
Droughts can reduce the nitrogen retention capacity of catchments
Hydrol. Earth Syst. Sci. 27 (1), 303 - 318 10.5194/hess-27-303-2023