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| Titel |
An assessment of the ability of Bartlett-Lewis type of rainfall models to reproduce drought statistics |
| VerfasserIn |
M. T. Pham, W. J. Vanhaute, S. Vandenberghe, B. Baets, N. E. C. Verhoest |
| 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 ; 17, no. 12 ; Nr. 17, no. 12 (2013-12-19), S.5167-5183 |
| Datensatznummer |
250086037
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| Publikation (Nr.) |
 copernicus.org/hess-17-5167-2013.pdf |
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| Zusammenfassung |
| Of all natural disasters, the economic and environmental
consequences of droughts are among the highest because of their
longevity and widespread spatial extent. Because of their extreme
behaviour, studying droughts generally requires long time series of
historical climate data. Rainfall is a very important variable for
calculating drought statistics, for quantifying historical droughts
or for assessing the impact on other hydrological (e.g. water stage
in rivers) or agricultural (e.g. irrigation requirements)
variables. Unfortunately, time series of historical observations are
often too short for such assessments. To circumvent this, one may
rely on the synthetic rainfall time series from stochastic point
process rainfall models, such as Bartlett–Lewis models. The present
study investigates whether drought statistics are preserved when
simulating rainfall with Bartlett–Lewis models. Therefore,
a 105 yr 10 min rainfall time series obtained at Uccle,
Belgium is used as a test case. First, drought events were identified
on the basis of the Effective Drought Index (EDI), and each event
was characterized by two variables, i.e. drought duration (D) and
drought severity (S). As both parameters are interdependent,
a multivariate distribution function, which makes use of a copula,
was fitted. Based on the copula, four types of drought return
periods are calculated for observed as well as simulated droughts
and are used to evaluate the ability of the rainfall models to
simulate drought events with the appropriate
characteristics. Overall, all Bartlett–Lewis model types studied
fail to preserve extreme drought statistics, which is attributed
to the model structure and to the model stationarity caused by
maintaining the same parameter set during the whole simulation period. |
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