Long-term dynamics of nitrogen export from European catchments
- 1Helmholtz Centre for Environmental Research - UFZ, Department of Computational Hydrosystems, Leipzig, Germany (fanny.sarrazin@ufz.de)
- 2Helmholtz Centre for Environmental Research - UFZ, Department of Hydrogeology, Leipzig, Germany
- 3Bayreuth Centre of Ecology and Environmental Research, University of Bayreuth, Bayreuth, Germany
- 4Institute of Environmental Science and Geography, University of Potsdam, Potsdam, Germany
Since the beginning of the twentieth century, anthropogenic activities have severely altered the global nitrogen (N) cycle through the fixation of atmospheric N for the production of N fertilizers, the cultivation of N fixing crops, fossil fuel combustion, and the discharge of human and industrial wastewater into the environment. Both N diffuse sources (fertilizer application, biological N fixation and atmospheric N deposition) and point sources (wastewater) have led to the contamination and eutrophication of numerous water bodies worldwide and are still threatening human and aquatic ecosystem health today. This calls for both large-scale and long-term analyses of N dynamics to gain a better understanding of the changes in N export from streams in response to changes in N input following environmental policies and technological developments.
In this study, we investigate the long-term dynamics of N export from European river basins over the last 70 years, which is made possible by our recent development of novel gridded datasets of long-term N diffuse sources and point sources across Europe (Batool et al., 2022). To this end, we apply the mHM hydrological model coupled with the SAS-N model (Nguyen et al., 2022). The latter accounts for possible N accumulation in the soil (biogeochemical legacy), as well as in the subsurface (hydrological legacy) utilizing water travel time via StorAge Selection (SAS) functions. We quantify N export in major European river basins (e.g. Danube, Elbe, Rhine, Rhone, Seine) accounting for the uncertainties in input data and model parameters (Sarrazin et al., 2022). We identify distinct relationships between N inputs and simulated N export, resulting from different legacy behaviours across river basins. Overall, we find a decreasing contribution of point sources to total N export over the study period, due to improvements in wastewater treatment. Through learning from the past N export dynamics, our study ultimately contributes to informing the development of future management strategies to reduce N levels below target values.
Batool, M., Sarrazin, F. J., Attinger, S., Basu, N. B., Van Meter, K., & Kumar, R. (2022). Long-term annual soil nitrogen surplus across Europe (1850–2019). Sci. Data, 9, 612. https://doi.org/10.1038/s41597-022-01693-9
Nguyen, T. V., Sarrazin, F. J., Ebeling, P., Musolff, A., Fleckenstein, J. H., & Kumar, R. (2022). Toward understanding of long-term nitrogen transport and retention dynamics across German catchments. Geophys. Res. Lett., 49, e2022GL100278. https://doi.org/10.1029/2022GL100278
Sarrazin, F. J., Kumar, R., Basu, N. B., Musolff, A., Weber, M., Van Meter, K. J., & Attinger, S. (2022). Characterizing catchment-scale nitrogen legacies and constraining their uncertainties. Water Resour. Res., 58, e2021WR031587. https://doi.org/10.1029/2021WR031587
How to cite: Sarrazin, F., Nguyen, T., Musolff, A., Ebeling, P., Batool, M., Sarker, P., Anpilova, Y., Fleckenstein, J., Attinger, S., and Kumar, R.: Long-term dynamics of nitrogen export from European catchments, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-4144, https://doi.org/10.5194/egusphere-egu23-4144, 2023.
