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| Titel |
A space-time hybrid hourly rainfall model for derived flood frequency analysis |
| VerfasserIn |
U. Haberlandt, A.-D. Ebner von Eschenbach, I. Buchwald |
| 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 ; 12, no. 6 ; Nr. 12, no. 6 (2008-12-15), S.1353-1367 |
| Datensatznummer |
250010962
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| Publikation (Nr.) |
 copernicus.org/hess-12-1353-2008.pdf |
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| Zusammenfassung |
For derived flood frequency analysis based on hydrological modelling long
continuous precipitation time series with high temporal resolution are
needed. Often, the observation network with recording rainfall gauges is
poor, especially regarding the limited length of the available rainfall time
series. Stochastic precipitation synthesis is a good alternative either to
extend or to regionalise rainfall series to provide adequate input for
long-term rainfall-runoff modelling with subsequent estimation of design
floods. Here, a new two step procedure for stochastic synthesis of
continuous hourly space-time rainfall is proposed and tested for the
extension of short observed precipitation time series.
First, a single-site alternating renewal model is presented to simulate
independent hourly precipitation time series for several locations. The
alternating renewal model describes wet spell durations, dry spell durations
and wet spell intensities using univariate frequency distributions
separately for two seasons. The dependence between wet spell intensity and
duration is accounted for by 2-copulas. For disaggregation of the wet spells
into hourly intensities a predefined profile is used. In the second step a
multi-site resampling procedure is applied on the synthetic point rainfall
event series to reproduce the spatial dependence structure of rainfall.
Resampling is carried out successively on all synthetic event series using
simulated annealing with an objective function considering three bivariate
spatial rainfall characteristics. In a case study synthetic precipitation is
generated for some locations with short observation records in two mesoscale
catchments of the Bode river basin located in northern Germany. The
synthetic rainfall data are then applied for derived flood frequency
analysis using the hydrological model HEC-HMS. The results show good
performance in reproducing average and extreme rainfall characteristics as
well as in reproducing observed flood frequencies. The presented model has
the potential to be used for ungauged locations through regionalisation of
the model parameters. |
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