 |
| Titel |
Impacts of climate change on the seasonality of low flows in 134 catchments in the River Rhine basin using an ensemble of bias-corrected regional climate simulations |
| VerfasserIn |
M. C. Demirel, M. J. Booij, A. Y. Hoekstra |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
1027-5606
|
| Digitales Dokument |
URL |
| Erschienen |
In: Hydrology and Earth System Sciences ; 17, no. 10 ; Nr. 17, no. 10 (2013-10-29), S.4241-4257 |
| Datensatznummer |
250085976
|
| Publikation (Nr.) |
 copernicus.org/hess-17-4241-2013.pdf |
|
|
|
|
|
| Zusammenfassung |
The impacts of climate change on the seasonality of low flows were analysed
for 134 sub-catchments covering the River Rhine basin upstream of the
Dutch-German border. Three seasonality indices for low flows were estimated,
namely the seasonality ratio (SR), weighted mean occurrence day (WMOD) and
weighted persistence (WP). These indices are related to the discharge regime,
timing and variability in timing of low flow events respectively. The three
indices were estimated from: (1) observed low flows; (2) simulated low flows
by the semi-distributed HBV model using observed climate as input; (3)
simulated low flows using simulated inputs from seven combinations of
General Circulation Models (GCMs) and Regional Climate Models (RCMs) for the
current climate (1964–2007); (4) simulated low flows using simulated inputs
from seven combinations of GCMs and RCMs for the future climate (2063–2098)
including three different greenhouse gas emission scenarios. These four
cases were compared to assess the effects of the hydrological model, forcing
by different climate models and different emission scenarios on the three
indices.
Significant differences were found between cases 1 and 2. For instance, the
HBV model is prone to overestimate SR and to underestimate WP and simulates very
late WMODs compared to the estimated WMODs using observed discharges. Comparing the
results of cases 2 and 3, the smallest difference was found for the SR index,
whereas large differences were found for the WMOD and WP indices for the current
climate. Finally, comparing the results of cases 3 and 4, we found that SR
decreases substantially by 2063–2098 in all seven sub-basins of the River
Rhine. The lower values of SR for the future climate indicate a shift from
winter low flows (SR > 1) to summer low flows (SR < 1) in the
two Alpine sub-basins. The WMODs of low flows tend to be earlier than for the
current climate in all sub-basins except for the Middle Rhine and Lower Rhine
sub-basins. The WP values are slightly larger, showing that the predictability
of low flow events increases as the variability in timing decreases for the
future climate. From comparison of the error sources evaluated in this
study, it is obvious that different RCMs/GCMs have a larger influence on
the timing of low flows than different emission scenarios. Finally, this
study complements recent analyses of an international project (Rhineblick)
by analysing the seasonality aspects of low flows and extends the scope
further to understand the effects of hydrological model errors and climate
change on three important low flow seasonality properties: regime, timing
and persistence. |
| |
|
| Teil von |
|
|
|
|
|
|
|
|