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| Titel |
Assessment of climate change impact on hydrological extremes in two source regions of the Nile River Basin |
| VerfasserIn |
M. T. Taye, V. Ntegeka, N. P. Ogiramoi, P. Willems |
| 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. 1 ; Nr. 15, no. 1 (2011-01-20), S.209-222 |
| Datensatznummer |
250012597
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| Publikation (Nr.) |
 copernicus.org/hess-15-209-2011.pdf |
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| Zusammenfassung |
The potential impact of climate change was investigated on the hydrological
extremes of Nyando River and Lake Tana catchments, which are located in two
source regions of the Nile River basin. Climate change scenarios were
developed for rainfall and potential evapotranspiration (ETo), considering
17 General Circulation Model (GCM) simulations to better understand the
range of possible future change. They were constructed by transferring the
extracted climate change signals to the observed series using a frequency
perturbation downscaling approach, which accounts for the changes in
rainfall extremes. Projected changes under two future SRES emission
scenarios A1B and B1 for the 2050s were considered. Two conceptual
hydrological models were calibrated and used for the impact assessment.
Their difference in simulating the flows under future climate scenarios was
also investigated.
The results reveal increasing mean runoff and extreme peak flows for Nyando
catchment for the 2050s while unclear trend is observed for Lake Tana
catchment for mean volumes and high/low flows. The hydrological models for
Lake Tana catchment, however, performed better in simulating the
hydrological regimes than for Nyando, which obviously also induces a
difference in the reliability of the extreme future projections for both
catchments. The unclear impact result for Lake Tana catchment implies that
the GCM uncertainty is more important for explaining the unclear trend than
the hydrological models uncertainty. Nevertheless, to have a better
understanding of future impact, hydrological models need to be verified for
their credibility of simulating extreme flows. |
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