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| Titel |
A framework for assessing hydrological regime sensitivity to climate change in a convective rainfall environment: a case study of two medium-sized eastern Mediterranean catchments, Israel |
| VerfasserIn |
N. Peleg, E. Shamir, K. P. Georgakakos, E. Morin |
| 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 ; 19, no. 1 ; Nr. 19, no. 1 (2015-01-29), S.567-581 |
| Datensatznummer |
250120609
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| Publikation (Nr.) |
 copernicus.org/hess-19-567-2015.pdf |
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| Zusammenfassung |
| A modeling framework is formulated and applied to assess the
sensitivity of the hydrological regime of two catchments in
a convective rainfall environment with respect to projected climate
change. The study uses likely rainfall scenarios with high
spatiotemporal resolution that are dependent on projected changes in
the driving regional meteorological synoptic systems. The framework
was applied to a case study in two medium-sized Mediterranean
catchments in Israel, affected by convective rainfall, by combining
the HiReS-WG rainfall generator and the SAC-SMA hydrological
model. The projected climate change impact on the hydrological
regime was examined for the RCP4.5 and RCP8.5 emission scenarios,
comparing the historical (beginning of the 21st century) and
future (mid-21st-century) periods from three general
circulation model simulations available from CMIP5. Focusing on
changes in the occurrence frequency of regional synoptic systems and
their impact on rainfall and streamflow patterns, we find that the
mean annual rainfall over the catchments is projected to be reduced
by 15% (outer range 2–23%) and 18% (7–25%) for the
RCP4.5 sand RCP8.5 emission scenarios, respectively. The mean annual
streamflow volumes are projected to be reduced by 45%
(10–60%) and 47% (16–66%). The average events'
streamflow volumes for a given event rainfall depth are projected to
be lower by a factor of 1.4–2.1. Moreover, the streamflow season in
these ephemeral streams is projected to be shorter by 22% and
26–28% for the RCP4.5 and RCP8.5, respectively. The
amplification in reduction of streamflow volumes relative to
rainfall amounts is related to the projected reduction in soil
moisture, as a result of fewer rainfall events and longer dry spells
between rainfall events during the wet season. The dominant factors
for the projected reduction in rainfall amount were the reduction in
occurrence of wet synoptic systems and the shortening of the wet
synoptic systems durations. Changes in the occurrence frequency of
the two dominant types of the regional wet synoptic systems (active
Red Sea trough and Mediterranean low) were found to have a minor
impact on the total rainfall. |
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