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| Titel |
Parameter extrapolation to ungauged basins with a hydrological distributed model in a regional framework |
| VerfasserIn |
J. J. Vélez, M. Puricelli, F. López Unzu, F. Francés |
| 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 ; 13, no. 2 ; Nr. 13, no. 2 (2009-02-23), S.229-246 |
| Datensatznummer |
250011764
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| Publikation (Nr.) |
 copernicus.org/hess-13-229-2009.pdf |
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| Zusammenfassung |
| A Regional Water Resources study was performed at basins within and draining
to the Basque Country Region (N of Spain), with a total area of
approximately 8500 km2. The objective was to obtain daily and monthly
long-term discharges in 567 points, most of them ungauged, with basin areas
ranging from 0.25 to 1850 km2. In order to extrapolate the calibrations
at gauged points to the ungauged ones, a distributed and conceptually based
model called TETIS was used. In TETIS the runoff production is modelled
using five linked tanks at the each cell with different outflow
relationships at each tank, which represents the main hydrological processes
as snowmelt, evapotranspiration, overland flow, interflow and base flow. The
routing along the channels' network couples its geomorphologic
characteristics with the kinematic wave approach. The parameter estimation
methodology tries to distinguish between the effective parameter used in the
model at the cell scale, and the watershed characteristic estimated from the
available information, being the best estimation without losing its physical
meaning. The relationship between them can be considered as a correction
function or, in its simple form, a correction factor. The correction factor
can take into account the model input errors, the temporal and spatial scale
effects and the watershed characteristics. Therefore, it is reasonable to
assume the correction factor is the same for each parameter to all cells
within the watershed. This approach reduces drastically the number of
parameter to be calibrated, because only the common correction factors are
calibrated instead of parameter maps (number of parameters times the number
of cells). In this way, the calibration can be performed using automatic
methodologies. In this work, the Shuffled Complex Evolution – University of
Arizona, SCE-UA algorithm was used. The available recent year's data was
used to calibrate the model in 20 of the most representative flow gauge
stations in 18 basins with a Nash-Sutcliffe index higher than 0.6 (10 higher
than 0.8). The calibrated correction factors at each basin were similar but
not equal. The validation process (in time and space) was performed using
the remaining data in all flow gauge stations (62), with 42 basins with a
Nash-Sutcliffe index higher than 0.5 (25 higher than 0.7). Deficient
calibration and validations were always related with flow gauge stations
very close to the karstic springs. These results confirmed that it was
feasible and efficient to use the SCE-UA algorithm for the automatic
calibration of distributed conceptual models and the calibrated model could
be used at ungauged basins. Finally, meteorological information from the
past 50 years at a daily scale was used to generate a daily discharges
series at 567 selected points. |
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