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Titel |
Runoff regime estimation at high-elevation sites: a parsimonious water balance approach |
VerfasserIn |
E. Bartolini, P. Allamano, F. Laio, P. Claps |
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 ; 15, no. 5 ; Nr. 15, no. 5 (2011-05-30), S.1661-1673 |
Datensatznummer |
250012795
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Publikation (Nr.) |
copernicus.org/hess-15-1661-2011.pdf |
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Zusammenfassung |
We develop a water balance model, parsimonious both in terms of
parameterization and of required input data, to characterize the
average runoff regime of high-elevation and scarcely monitored
basins. The model uses a temperature threshold to partition
precipitation into rainfall and snowfall, and to estimate
evapotranspiration volumes. The role of snow in the transformation
of precipitation into runoff is investigated at the monthly time
scale through a specific snowmelt module that estimates melted
quantities by a non-linear function of temperature. A
probabilistic representation of temperature is also introduced, in
order to mimic its sub-monthly variability. To account for the
commonly reported rainfall underestimation at high elevations, a
two-step precipitation adjustment procedure is
implemented to guarantee the closure of the water balance.
The model is applied to a group of catchments in the North-Western
Italian Alps, and its performances are assessed by comparing
measured and simulated runoff regimes both in terms of total bias
and anomalies, by means of a new metric, specifically conceived to
compare the shape of the two curves. The obtained results
indicates that the model is able to predict the observed runoff
seasonality satisfactorily, notwithstanding its parsimony (the
model has only two parameters to be estimated). In particular,
when the parameter calibration is performed separately for each
basin, the model proves to be able to reproduce the runoff
seasonality. At the regional scale (i.e., with uniform parameters
for the whole region), the performance is less positive, but the
model is still able to discern among different mechanisms of
runoff formation that depend on the role of the snow storage.
Because of its parsimony and the robustness in the approach, the
model is suitable for application in ungauged basins and for large
scale investigations of the role of climatic variables on water
availability and runoff timing in mountainous regions. |
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