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Titel |
Hydrologic impact of climate change on Murray–Hotham catchment of Western Australia: a projection of rainfall–runoff for future water resources planning |
VerfasserIn |
S. A. Islam, M. A. Bari, A. H. M. F. Anwar |
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 ; 18, no. 9 ; Nr. 18, no. 9 (2014-09-12), S.3591-3614 |
Datensatznummer |
250120468
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Publikation (Nr.) |
copernicus.org/hess-18-3591-2014.pdf |
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Zusammenfassung |
Reduction of rainfall and runoff in recent years across southwest Western
Australia (SWWA) has attracted attention to the climate change impact on water
resources and water availability in this region. In this paper, the hydrologic
impact of climate change on the Murray–Hotham catchment in SWWA has been
investigated using a multi-model ensemble approach through projection of
rainfall and runoff for the periods mid (2046–2065) and late (2081–2100) this century.
The Land Use Change Incorporated Catchment (LUCICAT) model was used for
hydrologic modelling. Model calibration was performed using (5 km) grid
rainfall data from the Australian Water Availability Project (AWAP). Downscaled
and bias-corrected rainfall data from 11 general circulation models (GCMs)
for Intergovernmental Panel on Climate Change (IPCC) emission scenarios A2
and B1 was used in LUCICAT model to derive rainfall and runoff scenarios for
2046–2065 (mid this century) and 2081–2100 (late this century). The results
of the climate scenarios were compared with observed past (1961–1980) climate.
The mean annual rainfall averaged over the catchment during recent time
(1981–2000) was reduced by 2.3% with respect to the observed past
(1961–1980) and the resulting runoff reduction was found to be 14%. Compared to
the past, the mean annual rainfall reductions, averaged over 11 ensembles and
over the period for the catchment for A2 scenario are 13.6 and 23.6% for
mid and late this century respectively while the corresponding runoff
reductions are 36 and 74%. For B1 scenario, the rainfall reductions were
11.9 and 11.6% for mid and late this century and the corresponding runoff
reductions were 31 and 38%. Spatial distribution of rainfall and runoff
changes showed that the rate of changes were higher in high rainfall areas
compared to low rainfall areas. Temporal distribution of rainfall and
runoff indicate that high rainfall events in the catchment reduced
significantly and further reductions are projected, resulting in significant
runoff reductions. A catchment scenario map has been developed by
plotting decadal runoff reduction against corresponding rainfall reduction at
four gauging stations for the observed and projected periods. This could be useful
for planning future water resources in the catchment. Projection of rainfall
and runoff made based on the GCMs varied significantly for the time periods
and emission scenarios. Hence, the considerable uncertainty involved in this
study though ensemble mean was used to explain the findings. |
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