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| Titel |
Simulation of the snowmelt runoff contributing area in a small alpine basin |
| VerfasserIn |
C. M. DeBeer, J. W. Pomeroy |
| 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 ; 14, no. 7 ; Nr. 14, no. 7 (2010-07-09), S.1205-1219 |
| Datensatznummer |
250012364
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| Publikation (Nr.) |
 copernicus.org/hess-14-1205-2010.pdf |
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| Zusammenfassung |
| Simulation of areal snowmelt and snowcover depletion over time can be
carried out by applying point-scale melt rate computations to distributions
of snow water equivalent (SWE). In alpine basins, this can be done by
considering these processes separately on individual slope units. However,
differences in melt timing and rates arise at smaller spatial scales due to
the variability in SWE and snowpack cold content, which affects the timing
of melt initiation, depletion of the snowcover and spatial extent of the
snowmelt runoff contributing area (SRCA). This study examined the effects of
variability in SWE, internal energy and applied melt energy on melt rates
and timing, and snowcover depletion in a small cold regions alpine basin
over various scales ranging from point to basin. Melt rate computations were
performed using a physically based energy balance snowmelt routine (Snobal)
in the Cold Regions Hydrological Model (CRHM) and compared with measurements
at 3 meteorological stations over a ridge within the basin. At the point
scale, a negative association between daily melt rates and SWE was observed
in the early melt period, with deeper snow requiring greater energy inputs
to initiate melt. SWE distributions over the basin (stratified by slope)
were measured using snow surveys and repeat LiDAR depth estimates, and used
together with computed melt rates to simulate the areal snowcover depletion.
Comparison with observations from georeferenced oblique photographs showed
an improvement in simulated areal snowcover depletion curves when accounting
for the variability in melt rate with depth of SWE in the early melt period.
Finally, the SRCA was characterized as the product of the snowcovered area
and the fraction of the SWE distribution undergoing active melt and
producing an appreciable runoff quantity on each slope unit. Results for
each slope were then aggregated to give the basin scale SRCA. The SRCA is
controlled by the variability of melt amongst slope units and over
individual SWE distributions, the variability of SWE, and the resulting
snowcover depletion patterns over the basin. |
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