Details zur Publikation

Kategorie Textpublikation
Referenztyp Zeitschriften
DOI 10.1016/j.jhydrol.2022.128615
Titel (primär) Exploring the relations between sequential droughts and stream nitrogen dynamics in central Germany through catchment-scale mechanistic modelling
Autor Zhou, X.; Jomaa, S.; Yang, X.; Merz, R.; Wang, Y.; Rode, M.
Quelle Journal of Hydrology
Erscheinungsjahr 2022
Department ASAM; CATHYD
Band/Volume 614, Part B
Seite von art. 128615
Sprache englisch
Topic T5 Future Landscapes
Daten-/Softwarelinks https://doi.org/10.5281/zenodo.3891628
Keywords Drought; Nitrate mixing; Catchment hydrology; Water quality model
Abstract Like many other regions in central Europe, Germany experienced sequential summer droughts from 2015 to 2018. As one of the environmental consequences, river nitrate concentrations have exhibited significant changes in many catchments. However, catchment nitrate responses to the changing weather conditions have not yet been mechanistically explored. Thus, a fully distributed, process-based catchment Nitrate model (mHM-Nitrate) was used to reveal the causal relations in the Bode catchment, of which river nitrate concentrations have experienced contrasting trends from upstream to downstream reaches. The model was evaluated using data from six gauging stations, reflecting different levels of runoff components and their associated nitrate-mixing from upstream to downstream. Results indicated that the mHM-Nitrate model reproduced dynamics of daily discharge and nitrate concentration well, with Nash-Sutcliffe Efficiency 0.73 for discharge and Kling-Gupta Efficiency ≥0.50 for nitrate concentration at most stations. Particularly, the spatially contrasting trends of nitrate concentration were successfully captured by the model. The decrease of nitrate concentration in the lowland area in drought years (2015–2018) was presumably due to (1) limited terrestrial export loading (ca. 40 % lower than that of normal years 2004–2014), and (2) increased in-stream retention efficiency (20 % higher in summer within the whole river network). From a mechanistic modelling perspective, this study provided insights into spatially heterogeneous flow and nitrate dynamics and effects of sequential droughts, which shed light on water-quality responses to future climate change, as droughts are projected to be more frequent.
dauerhafte UFZ-Verlinkung https://www.ufz.de/index.php?en=20939&ufzPublicationIdentifier=26762
Zhou, X., Jomaa, S., Yang, X., Merz, R., Wang, Y., Rode, M. (2022):
Exploring the relations between sequential droughts and stream nitrogen dynamics in central Germany through catchment-scale mechanistic modelling
J. Hydrol. 614, Part B , art. 128615 10.1016/j.jhydrol.2022.128615