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| Titel |
High-resolution Med-CORDEX regional climate model simulations for hydrological impact studies: a first evaluation of the ALADIN-Climate model in Morocco |
| VerfasserIn |
Y. Tramblay, D. Ruelland, S. Somot, R. Bouaicha, E. Servat |
| 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 ; 17, no. 10 ; Nr. 17, no. 10 (2013-10-02), S.3721-3739 |
| Datensatznummer |
250085942
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| Publikation (Nr.) |
 copernicus.org/hess-17-3721-2013.pdf |
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| Zusammenfassung |
| In the framework of the international CORDEX program, new regional climate
model (RCM) simulations at high spatial resolutions are becoming available
for the Mediterranean region (Med-CORDEX initiative). This study provides the
first evaluation for hydrological impact studies of one of these
high-resolution simulations in a 1800 km2 catchment located in North
Morocco. Different approaches are compared to analyze the climate change
impacts on the hydrology of this catchment using a high-resolution RCM
(ALADIN-Climate) from the Med-CORDEX initiative at two different spatial
resolutions (50 and 12 km) and for two different Radiative Concentration
Pathway scenarios (RCP4.5 and RCP8.5). The main issues addressed in the
present study are: (i) what is the impact of increased RCM resolution on
present-climate hydrological simulations and on future projections? (ii) Are
the bias-correction of the RCM model and the parameters of the hydrological
model stationary and transferable to different climatic conditions? (iii)
What is the climate and hydrological change signal based on the new Radiative
Concentration Pathways scenarios (RCP4.5 and RCP8.5)? Results indicate that
high resolution simulations at 12 km better reproduce the seasonal patterns,
the seasonal distributions and the extreme events of precipitation. The
parameters of the hydrological model, calibrated to reproduce runoff at the
monthly time step over the 1984–2010 period, do not show a strong
variability between dry and wet calibration periods in a differential
split-sample test. However the bias correction of precipitation by
quantile-matching does not give satisfactory results in validation using the
same differential split-sample testing method. Therefore a
quantile-perturbation method that does not rely on any stationarity
assumption and produces ensembles of perturbed series of precipitation was
introduced. The climate change signal under scenarios 4.5 and 8.5 indicates a
decrease of respectively −30 to −57% in surface runoff for the
mid-term (2041–2062), when for the same period the projections for
precipitation are ranging between −15 and −19% and for temperature
between +1.3 and +1.9 °C. |
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