 |
| Titel |
Sources of uncertainty in climate change impacts on river discharge and groundwater in a headwater catchment of the Upper Nile Basin, Uganda |
| VerfasserIn |
D. G. Kingston, R. G. Taylor |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
1027-5606
|
| Digitales Dokument |
URL |
| Erschienen |
In: Hydrology and Earth System Sciences ; 14, no. 7 ; Nr. 14, no. 7 (2010-07-16), S.1297-1308 |
| Datensatznummer |
250012370
|
| Publikation (Nr.) |
 copernicus.org/hess-14-1297-2010.pdf |
|
|
|
|
|
| Zusammenfassung |
| The changing availability of freshwater resources is likely to be one of the
most important consequences of projected 21st century climate change
for both human and natural systems. However, substantial uncertainty remains
regarding the precise impacts of climate change on water resources, due in
part due to uncertainty in GCM projections of climate change. Here we
explore the potential impacts of climate change on freshwater resources in a
humid, tropical catchment (the River Mitano) in the Upper Nile Basin of
Uganda. Uncertainty associated with GCM structure and climate sensitivity is
explored, as well as parameter specification within hydrological models.
These aims are achieved by running pattern-scaled output from seven GCMs
through a semi-distributed hydrological model of the catchment (developed
using SWAT). Importantly, use of pattern-scaled GCM output allows
investigation of specific thresholds of global climate change including the
purported 2 °C threshold of "dangerous" climate change. In-depth
analysis of results based on the HadCM3 GCM climate scenarios shows that
annual river discharge first increases, then declines with rising global
mean air temperature. A coincidental shift from a bimodal to unimodal
discharge regime also results from a projected reduction in baseflow
(groundwater discharge). Both of these changes occur after a 4 °C rise
in global mean air temperature. These results are, however, highly GCM
dependent, in both the magnitude and direction of change. This dependence
stems primarily from projected differences in GCM scenario precipitation
rather than temperature. GCM-related uncertainty is far greater than that
associated with climate sensitivity or hydrological model parameterisation. |
| |
|
| Teil von |
|
|
|
|
|
|
|
|