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| Titel |
Geomorphic Signatures on Brutsaert Base Flow Recession Analysis |
| VerfasserIn |
Andrea Rinaldo, Raphael Mutzner, Enrico Bertuzzo, Paolo Tarolli, Steven Weijs, Serena Ceola, Nevena Tomasic, Ignacio Rodríguez-Iturbe, Marc Parlange |
| Konferenz |
EGU General Assembly 2013
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 15 (2013) |
| Datensatznummer |
250077106
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| Zusammenfassung |
| This paper addresses the signatures of catchment geomorphology on base flow recession
curves. Its relevance relates to the implied predictability of base flow features, which are
central to catchment-scale transport phenomena and to ecohydrological function. Moving
from the classical recession curve analysis method, originally applied to the Finger Lakes
Region, a large set of recession curves has been analyzed from Swiss streamflow data
relatively unaffected by snowmelt. For these catchments, digital terrain models have been
accurately analyzed. Recent results aimed at the geomorphic origins of recession curves have
been then applied to the Swiss dataset. The method links river network morphology,
epitomized by time-varying geometry of saturated channel sites, with the classic
parametrization of recession events, in particular by assimilating two scaling exponents, β
and bG (i.e. |dQ/dt|-Qβwhere Q is at-a-station gauged flow rate; N(l) -G(l)bG where l is
the downstream distance from the channel heads receding in time, N(l) is the number of
draining channel reaches located at distance l from their heads, and G(l) is the total drainage
network length at a distance greater or equal to l, the active drainage network). Here,
we confirm that the method provides good results, yet only in catchments where
drainage density can be regarded as spatially constant. A correction to the method is
proposed, which accounts for arbitrary local drainage densities affecting the local
drainage inflow per unit channel length. Such corrections properly vanish should
drainage density become spatially constant. A comparative analysis on the Swiss
streamflow and Digital Elevation Model data shows that the proposed correction
proves indeed statistically significant. Overall, definite geomorphic signatures are
recognized for recession curves, with notable theoretical and practical implications. |
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