Publication Details |
| Category | Text Publication |
| Reference Category | Journals |
| DOI | 10.1029/2021GB007050 |
| Licence |
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| Title (Primary) | Long-term nitrate trajectories vary by season in Western European catchments |
| Author | Ebeling, P.; Dupas, R.; Abbott, B.; Kumar, R.; Ehrhardt, S.; Fleckenstein, J.H.; Musolff, A. |
| Journal | Global Biogeochemical Cycles |
| Year | 2021 |
| Department | CHS; HDG |
| Volume | 35 |
| Issue | 9 |
| Page From | e2021GB007050 |
| Language | englisch |
| Topic | T5 Future Landscapes |
| Supplements | https://agupubs.onlinelibrary.wiley.com/action/downloadSupplement?doi=10.1029%2F2021GB007050&file=2021GB007050-sup-0001-Supporting+Information+SI-S01.pdf |
| Keywords | Catchment hydrology; Nitrate seasonality; Water quality; Long-term trends; Eutrophication; Controls |
| Abstract | Human alteration of nutrient cycles has caused persistent and widespread degradation of water quality around the globe. In many regions, including Western Europe, elevated nitrate (NO3-) concentration in surface waters contributes to eutrophication and noncompliance with environmental legislation. Discharge, NO3- concentrations and the vulnerability of the aquatic ecosystems to eutrophication often exhibit a distinct seasonality. Understanding spatial patterns and long-term trends in this seasonality is crucial to improve water quality management. Here, we hypothesized that NO3- concentrations during high-flow periods would respond faster to changes in nutrient inputs than low-flow concentrations because of greater connectivity of shallow diffuse NO3- sources with the river network. To test this hypothesis, we compiled long-term NO3- and discharge time series from 290 Western European catchments. To characterize the long-term trajectories of seasonal NO3- concentration, we propose a novel hysteresis approach comparing low- and high-flow NO3- concentration in the context of multi-decadal N input changes. We found synchronous winter maxima of NO3- and discharge in 84% of the study catchments. However, contrary to our hypothesis, there were surprisingly diverse long-term trajectories of seasonal NO3- concentration. Both clockwise (faster high-flow NO3- response) and counterclockwise hysteresis (faster low-flow NO3- response) occurred in similar proportions, potentially due to a high complexity in the underlying processes. Spatial variability of seasonality in NO3- concentration across the catchments was more pronounced and better predictable than its long-term variability. This work demonstrates the value of seasonal and inter-annual hydrochemical analysis and provides new tools for water quality monitoring and management. |
| Persistent UFZ Identifier | https://www.ufz.de/index.php?en=20939&ufzPublicationIdentifier=25028 |
| Ebeling, P., Dupas, R., Abbott, B., Kumar, R., Ehrhardt, S., Fleckenstein, J.H., Musolff, A. (2021): Long-term nitrate trajectories vary by season in Western European catchments Glob. Biogeochem. Cycles 35 (9), e2021GB007050 |
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