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| Titel |
On the spatio-temporal analysis of hydrological droughts from global hydrological models |
| VerfasserIn |
G. A. Corzo Perez, M. H. J. Huijgevoort, F. Voß, H. A. J. Lanen |
| 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 ; 15, no. 9 ; Nr. 15, no. 9 (2011-09-19), S.2963-2978 |
| Datensatznummer |
250012965
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| Publikation (Nr.) |
 copernicus.org/hess-15-2963-2011.pdf |
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| Zusammenfassung |
| The recent concerns for world-wide extreme events related to climate
change have motivated the development of large scale models
that simulate the global water cycle. In this context, analysis of
hydrological extremes is important and requires the adaptation of identification methods
used for river basin models. This paper presents
two methodologies that extend the tools to analyze spatio-temporal
drought development and characteristics using large scale gridded time
series of hydrometeorological data. The methodologies are
classified as non-contiguous and contiguous drought
area analyses (i.e. NCDA and CDA). The NCDA presents time series of
percentages of areas in drought at the global scale and for
pre-defined regions of known hydroclimatology. The CDA is introduced
as a complementary method that generates information on the spatial
coherence of drought events at the global scale. Spatial drought
events are found through CDA by clustering patterns (contiguous
areas). In this study the global hydrological model WaterGAP was used
to illustrate the methodology development. Global gridded time series of subsurface runoff
(resolution 0.5°) simulated with the WaterGAP model from land
points were used. The NCDA and CDA were developed to identify drought
events in runoff. The percentages of area in drought
calculated with both methods show complementary information on the
spatial and temporal events for the last decades of the 20th
century. The NCDA provides relevant information on the average number
of droughts, duration and severity (deficit volume) for pre-defined
regions (globe, 2 selected hydroclimatic regions). Additionally, the CDA
provides information on the number of spatially linked areas in
drought, maximum spatial event and their geographic location on the globe. Some results capture the
overall spatio-temporal drought extremes over the last decades of the
20th century. Events like the El Niño Southern Oscillation (ENSO) in
South America and the pan-European drought in 1976 appeared clearly in
both analyses. The methodologies introduced provide an important basis
for the global characterization of droughts, model inter-comparison of
drought identified from global hydrological models and spatial event analyses. |
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