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| Titel |
Introducing empirical and probabilistic regional envelope curves into a mixed bounded distribution function |
| VerfasserIn |
B. Guse, Th. Hofherr, B. Merz |
| 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. 12 ; Nr. 14, no. 12 (2010-12-09), S.2465-2478 |
| Datensatznummer |
250012525
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| Publikation (Nr.) |
 copernicus.org/hess-14-2465-2010.pdf |
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| Zusammenfassung |
A novel approach to consider additional spatial information in flood
frequency analyses, especially for the estimation of discharges with
recurrence intervals larger than 100 years, is presented. For this purpose,
large flood quantiles, i.e. pairs of a discharge and its corresponding
recurrence interval, as well as an upper bound discharge, are combined
within a mixed bounded distribution function. The large flood quantiles are
derived using probabilistic regional envelope curves (PRECs) for all sites
of a pooling group. These PREC flood quantiles are introduced into an
at-site flood frequency analysis by assuming that they are representative
for the range of recurrence intervals which is covered by PREC flood
quantiles. For recurrence intervals above a certain inflection point, a
Generalised Extreme Value (GEV) distribution function with a positive shape
parameter is used. This GEV asymptotically approaches an upper bound derived
from an empirical envelope curve. The resulting mixed distribution function
is composed of two distribution functions which are connected at the
inflection point.
This method is applied to 83 streamflow gauges in Saxony/Germany. Our
analysis illustrates that the presented mixed bounded distribution function
adequately considers PREC flood quantiles as well as an upper bound
discharge. The introduction of both into an at-site flood frequency analysis
improves the quantile estimation. A sensitivity analysis reveals that, for
the target recurrence interval of 1000 years, the flood quantile estimation
is less sensitive to the selection of an empirical envelope curve than to
the selection of PREC discharges and of the inflection point between the
mixed bounded distribution function. |
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