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| Titel |
Effects of intersite dependence of nested catchment structures on probabilistic regional envelope curves |
| VerfasserIn |
B. Guse, A. Castellarin, A. H. Thieken, 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 ; 13, no. 9 ; Nr. 13, no. 9 (2009-09-29), S.1699-1712 |
| Datensatznummer |
250011999
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| Publikation (Nr.) |
 copernicus.org/hess-13-1699-2009.pdf |
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| Zusammenfassung |
| This study analyses the intersite dependence of nested catchment structures
by modelling cross-correlations for pairs of nested and unnested catchments
separately. Probabilistic regional envelope curves are utilised to derive
regional flood quantiles for 89 catchments located in Saxony, in the
Southeast of Germany. The study area has a nested structure and the
intersite correlation is much stronger for nested pairs of catchments than
for unnested ones. Pooling groups of sites (regions) are constructed based
on several candidate sets of catchment descriptors using the Region of
Influence method. Probabilistic regional envelope curves are derived on the
basis of flood flows observed within the pooling groups. Their estimated
recurrence intervals are based on the number of effective sample years of
data (i.e. equivalent number of uncorrelated data). The evaluation of the
effective sample years of data requires the modelling of intersite
dependence. We perform this globally, using a cross-correlation function for
the whole study area as well as by using two different cross-correlation
functions, one for nested pairs and another for unnested pairs. In the
majority of the cases, these two modelling approaches yield significantly
different estimates for the effective sample years of data, and therefore
also for the recurrence intervals. The reduction of the recurrence interval
when using two different cross-correlation functions is larger for larger
pooling groups and for pooling groups with a higher fraction of nested
catchments. A separation into nested and unnested pairs of catchments gives
a more realistic representation of the characteristic river network
structure and improves the estimation of regional information content.
Hence, applying two different cross-correlation functions is recommended. |
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