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| Titel |
A conceptual investigation of process controls upon flood frequency: role of thresholds |
| VerfasserIn |
I. Struthers, M. Sivapalan  |
| 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 ; 11, no. 4 ; Nr. 11, no. 4 (2007-07-06), S.1405-1416 |
| Datensatznummer |
250009395
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| Publikation (Nr.) |
 copernicus.org/hess-11-1405-2007.pdf |
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| Zusammenfassung |
| Traditional statistical approaches to flood frequency inherently assume
homogeneity and stationarity in the flood generation process. This study
illustrates the impact of heterogeneity associated with threshold
non-linearities in the storage-discharge relationship associated with the
rainfall-runoff process upon flood frequency behaviour. For a simplified,
non-threshold (i.e. homogeneous) scenario, flood frequency can be
characterised in terms of rainfall frequency, the characteristic response
time of the catchment, and storm intermittency, modified by the relative
strength of evaporation. The flood frequency curve is then a consistent
transformation of the rainfall frequency curve, and could be readily
described by traditional statistical methods. The introduction of storage
thresholds, namely a field capacity storage and a catchment storage
capacity, however, results in different flood frequency "regions" associated
with distinctly different rainfall-runoff response behaviour and different
process controls. The return period associated with the transition between
these regions is directly related to the frequency of threshold exceedence.
Where threshold exceedence is relatively rare, statistical extrapolation of
flood frequency on the basis of short historical flood records risks
ignoring this heterogeneity, and therefore significantly underestimating the
magnitude of extreme flood peaks. |
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