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Titel |
Modelling nitrogen dynamics and distributions in the River Tweed, Scotland: an application of the INCA model |
VerfasserIn |
H. P. Jarvie, A. J. Wade, D. Butterfield, P. G. Whitehead, C. I. Tindall, W. A. Virtue, W. Dryburgh, A. McGraw |
Medientyp |
Artikel
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Sprache |
Englisch
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ISSN |
1027-5606
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Digitales Dokument |
URL |
Erschienen |
In: Hydrology and Earth System Sciences ; 6, no. 3 ; Nr. 6, no. 3, S.433-454 |
Datensatznummer |
250003562
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Publikation (Nr.) |
copernicus.org/hess-6-433-2002.pdf |
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Zusammenfassung |
The
INCA (Integrated Nitrogen in Catchments) model was applied to the River Tweed in
the Scottish Borders, a large-scale (4400km2), spatially
heterogeneous catchment, draining a wide range of agricultural land-use types,
and which contributes approximately 20% of UK river flows to the North Sea. The
model was calibrated for the first four years' data record (1994 to 1997) and
tested over the following three years (1998 to 2000). The model calibration and
testing periods incorporated a high degree of variability in climatic conditions
and river flows within the Tweed catchment. The ability of the INCA model to
reproduce broad-scale spatial patterns and seasonal dynamics in river flows and
nitrate concentrations suggests that the processes controlling first order
variability in river water nitrate concentrations have been represented
successfully within the model. The tendency of the model to overestimate
summer/early autumn baseflow nitrate concentrations during dry years may be
linked to the operation of aquatic plant uptake effects. It is, therefore,
suggested that consideration be given to incorporating a spatially and
temporally variable in-stream plant uptake term for the application of INCA to
lowland eutrophic rivers. Scenarios to examine possible impacts of environmental
change on nitrate concentrations on the Tweed are examined. These include the
effects of (i) implementing different recommendations for fertiliser use and
land use change under the Nitrate Sensitive Areas (NSA) Scheme and the Scottish
Code of Good Agricultural Practice, (ii) worst case scenario changes linked to a
dramatic reduction in livestock numbers as a result of a crisis in UK livestock
farming and (iii) changes in atmospheric nitrogen deposition.
Keywords: Nitrate, nitrogen, modelling, Tweed, INCA |
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