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| Titel |
Streamflow sensitivity to climate and land cover changes: Meki River, Ethiopia |
| VerfasserIn |
D. Legesse, T. A. Abiye, C. Vallet-Coulomb, H. Abate |
| 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 ; 14, no. 11 ; Nr. 14, no. 11 (2010-11-17), S.2277-2287 |
| Datensatznummer |
250012483
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| Publikation (Nr.) |
 copernicus.org/hess-14-2277-2010.pdf |
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| Zusammenfassung |
| Impacts of climate and land cover changes on streamflow were assessed using
a hydrological modeling. The precipitation runoff modeling system of the US
Geological Survey was modified in order to consider wetlands as a separate
hydrological response unit. Initial model parameters were obtained from a
previously modeled adjacent catchment and subsequent calibration and
validation were carried out. The model calibration and validation periods
were divided into three. The calibration period was a five years period
(1981–1986). The validation period was divided into two: validation 1
(1986–1991) and validation 2 (1996–2002). Model performance was evaluated by
using joint plots of daily and monthly observed and simulated runoff
hydrographs and different coefficients of efficiency. The model coefficients
of efficiency were 0.71 for the calibration period and 0.69 and 0.66 for
validation periods 1 and 2, respectively. A "delta-change" method was used to
formulate climatic scenarios. One land cover change scenario was also used
to assess the likely impacts of these changes on the runoff. The results of
the scenario analysis showed that the basin is more sensitive to increase in
rainfall (+80% for +20%) than to a decrease (−62% for −20%). The
rainfall elasticity is 4:1 for a 20% increase in rainfall while it is 3:1
for a 20% reduction. A 1.5°c increase in temperature resulted in a
6% increase in potential evapotranspiration and 13% decrease in
streamflow. This indicates that the watershed is more elastic to rainfall
increase than temperature. The proposed land cover scenario of converting
areas between 2000 to 3000 m a.s.l. to woodland also resulted in a
significant decrease in streamflow (11.8%). The study showed that
properly calibrated and validated models could help understand likely
impacts of climate and land cover changes on catchment water balance. |
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