Details zur Publikation

Kategorie Textpublikation
Referenztyp Zeitschriften
DOI 10.1029/2020WR028490
Lizenz creative commons licence
Titel (primär) Modeling nitrate export from a mesoscale catchment using StorAge selection functions
Autor Nguyen, V.T. ORCID logo ; Kumar, R. ORCID logo ; Lutz, S.R.; Musolff, A.; Yang, J.; Fleckenstein, J.H.
Quelle Water Resources Research
Erscheinungsjahr 2021
Department CHS; HDG
Band/Volume 57
Heft 2
Seite von e2020WR028490
Sprache englisch
Topic T5 Future Landscapes
Keywords storAge selection functions; nitrate export; transit time; subsurface mixing ; mesoscale catchment; distributed model
Abstract StorAge Selection (SAS) functions describe how catchments selectively remove water of different ages in storage via discharge, thus controlling the transit time distribution (TTD) and solute composition of discharge. SAS‐based models have been emerging as promising tools for quantifying catchment‐scale solute export, providing a coherent framework for describing both velocity and celerity driven transport. Due to their application in headwaters only, the spatial heterogeneity of catchment physiographic characteristics, land‐use management practices, and large‐scale validation have not been adequately addressed with SAS‐based models. Here we integrated SAS functions into the grid‐based mHM‐Nitrate model (mesoscale Hydrological Model) at both grid scale (distributed model) and catchment scale (lumped model). The proposed model provides a spatially distributed representation of nitrogen dynamics within the soil zone and a unified approach for representing both velocity and celerity driven subsurface transport below the soil zone. The model was tested in a heterogeneous mesoscale catchment. Simulated results show a strong spatial heterogeneity in nitrogen dynamics within the soil zone, highlighting the necessity of a spatially explicit approach for describing near‐surface nitrogen processing. The lumped model could well capture instream nitrate concentration dynamics and the concentration‐discharge relationship at the catchment outlet. In addition, the model could provide insights into the relations between subsurface storage, mixing scheme, solute export, and the TTDs of discharge. The distributed model shows results that are comparable to the lumped model. Overall, the results reveal the potential for large‐scale applications of SAS‐based transport models, contributing to the understanding of water quality‐related issues in agricultural landscapes.
dauerhafte UFZ-Verlinkung
Nguyen, V.T., Kumar, R., Lutz, S.R., Musolff, A., Yang, J., Fleckenstein, J.H. (2021):
Modeling nitrate export from a mesoscale catchment using StorAge selection functions
Water Resour. Res. 57 (2), e2020WR028490 10.1029/2020WR028490