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| Titel |
Stream recession curves and storage variability in small watersheds |
| VerfasserIn |
N. Y. Krakauer, M. Temimi |
| 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. 7 ; Nr. 15, no. 7 (2011-07-26), S.2377-2389 |
| Datensatznummer |
250012900
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| Publikation (Nr.) |
 copernicus.org/hess-15-2377-2011.pdf |
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| Zusammenfassung |
| The pattern of streamflow recession after rain events offers clues about the
relationship between watershed runoff (observable as river discharge) and
water storage (not directly observable) and can help in water resource
assessment and prediction. However, there have been few systematic
assessments of how streamflow recession varies across flow rates and how it
relates to independent assessments of terrestrial water storage. We
characterized the streamflow recession pattern in 61 relatively undisturbed
small watersheds (1–100 km2) across the coterminous United States with
multiyear records of hourly streamflow from automated gauges. We used the
North American Regional Reanalysis to help identify periods where
precipitation, snowmelt, and evaporation were small compared to streamflow.
The order of magnitude of the recession timescale increases from 1 day at
high flow rates (~1 mm h−1) to 10 days at low flow rates (~0.01 mm h−1),
leveling off at low flow rates. There is significant variability in
the recession timescale at a given flow rate between basins, which correlates
with climate and geomorphic variables such as the ratio of mean streamflow to
precipitation and soil water infiltration capacity. Stepwise multiple
regression was used to construct a six-variable predictive model that
explained some 80 % of the variance in recession timescale at high flow rates
and 30–50 % at low flow rates. Seasonal and interannual variability in
inferred storage shows similar time evolution to regional-scale water storage
variability estimated from GRACE satellite gravity data and from land surface
modeling forced by observed meteorology, but is up to a factor of 10 smaller.
Study of this discrepancy in the inferred storage amplitude may provide clues
to the range of validity of the recession curve approach to relating runoff
and storage. |
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