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Titel |
SWAT model calibration of a grid-based setup |
VerfasserIn |
H. Rathjens, N. Oppelt |
Medientyp |
Artikel
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Sprache |
Englisch
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ISSN |
1680-7340
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Digitales Dokument |
URL |
Erschienen |
In: Proceedings of the 15th Workshop on Large-scale Hydrological Modelling ; Nr. 32 (2012-12-11), S.55-61 |
Datensatznummer |
250017325
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Publikation (Nr.) |
copernicus.org/adgeo-32-55-2012.pdf |
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Zusammenfassung |
The eco-hydrological model SWAT (Soil and Water Assessment Tool) is a useful
tool to simulate the effects of catchment processes and water management
practices on the water cycle. For each catchment some model parameters (e.g.
ground water delay time, ground water level) remain constant and therefore
are used as constant values; other parameters such as soil types or land use
are spatially variable and thus have to be spatially discretized. SWAT setup
interfaces process input data to fit the data format requirements and to
discretize the spatial characteristics of the catchment area. The primarily
used configuration is the sub-watershed discretization scheme. This spatial
setup method, however, results in a loss of spatial information which can be
problematic for SWAT applications that require a spatially detailed
description of the catchment area. At present no SWAT interface is available
which provides the management of input and output data based on grid cells.
To fill this gap, the authors developed a grid-based model interface.
To perform hydrological studies, the SWAT user first calibrates the model to
fit to the environmental and hydrological conditions of the catchment.
Compared to the sub-watershed approach, the grid-based setup significantly
increases model computation time and hence aggravates calibration according
to established calibration guidelines. This paper describes how a
conventional set of sub-watershed SWAT parameters can be used to calibrate
the corresponding grid-based model. The procedure was evaluated in a
sub-catchment of the River Elbe (Northern Germany). The simulation of daily
discharge resulted in Nash-Sutcliffe efficiencies ranging from 0.76 to 0.78
and from 0.61 to 0.65 for the calibration and validation period respectively;
thus model performance is satisfactory. The sub-watershed and grid
configuration simulate comparable discharges at the catchment outlet
(R2 = 0.99). Nevertheless, the major advantage of the grid-based set-up is
an enhanced spatial description of landscape units inducing a more realistic
spatial distribution of model output parameters. |
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