Publication Details

Category Text Publication
Reference Category Journals
DOI 10.1016/j.jhydrol.2005.12.017
Title (Primary) Modelling nitrate transport and turnover in a lowland catchment system
Author Wriedt, G.; Rode, M.
Source Titel Journal of Hydrology
Year 2006
Department ASAM; HYMOD
Volume 328
Issue 1-2
Page From 157
Page To 176
Language englisch
Keywords Diffuse pollution; Reactive transport; Groundwater; Denitrification; Modelling; Catchment; Nitrate
Abstract

Nitrate transport in groundwater dominated lowland catchment systems is influenced by complex and spatially distributed physical and chemical interactions. A modelling approach was developed combining a distributed soil nitrogen model with a three-dimensional groundwater model and a reactive transport model linking nitrate turnover and availability of reaction partners such as pyrite and organic matter. The modelling approach was applied to a hypothetical case study based on data from the pleistocene lowland catchment “Schaugraben” (20 km2) in the North of Saxony-Anhalt, with focus on the investigation of interactions of spatially distributed transport and chemical processes. The modelling approach could successfully simulate transport and turnover of nitrate in a groundwater dominated catchment. The advancement of the nitrate front and the corresponding depletion of pyrite as well as the distribution of seepage fluxes and nitrate concentrations in seepage water in the channel system showed distinct spatial variation. Surface water nitrate concentrations corresponding to the average soil leachate concentrations were not completely reached after a simulation period of 200 years for a conservative transport simulation. Under reactive conditions, about 80% of the nitrate was lost due to denitrification. Given a uniformly distributed input of nitrate, drain loads developed in a sigmoidal curve defined only by travel time distribution. The average travel time was 93 years. A distributed input of nitrate resulted in reduction of travel time to 80 years due to the different arrangement of source areas and flow.

The modelling approach is a step towards bridging the gap between simple large scale models and detailed small scale studies, maintaining process orientation while allowing to consider landscape heterogeneity.

Persistent UFZ Identifier https://www.ufz.de/index.php?en=20939&ufzPublicationIdentifier=3138
Wriedt, G., Rode, M. (2006):
Modelling nitrate transport and turnover in a lowland catchment system
J. Hydrol. 328 (1-2), 157 - 176 10.1016/j.jhydrol.2005.12.017