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| Titel |
Groundwater as an emergency source for drought mitigation in the Crocodile River catchment, South Africa |
| VerfasserIn |
F. E. F. Mussá, Y. Zhou, S. Maskey, I. Masih, S. Uhlenbrook |
| 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. 2 ; Nr. 19, no. 2 (2015-02-26), S.1093-1106 |
| Datensatznummer |
250120640
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| Publikation (Nr.) |
 copernicus.org/hess-19-1093-2015.pdf |
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| Zusammenfassung |
| Global climate change has received much attention worldwide in the
scientific as well as in the political community, indicating that changes in
precipitation, extreme droughts and floods may increasingly threaten many
regions. Drought is a natural phenomenon that causes social, economical
and environmental damage to society. In this study, we assess the
drought intensity and severity and the groundwater potential to be used as a
supplementary source of water to mitigate drought impacts in the Crocodile
River catchment, a water-stressed sub-catchment of the Incomati River
catchment in South Africa. The research methodology consists of three
parts. First, the spatial and temporal variation of the meteorological and
hydrological drought severity and intensity over the catchment were
evaluated. The Standardized Precipitation Index (SPI) was used to analyse
the meteorological drought and the Standardized Runoff Index (SRI) was used
for the hydrological drought. Second, the water deficit in the catchment
during the drought period was computed using a simple water balance method.
Finally, a groundwater model was constructed in order to assess the
feasibility of using groundwater as an emergency source for drought impact
mitigation. Results show that the low-rainfall areas are more vulnerable to
severe meteorological droughts (lower and upper crocodile). Moreover, the
most water stressed sub-catchments with high level of water uses but limited
storage, such as the Kaap located in the middle catchment and the Lower
Crocodile sub-catchments, are more vulnerable to severe hydrological
droughts. The analysis of the potential groundwater use during droughts
showed that a deficit of 97 Mm3 yr−1 could be supplied from groundwater
without considerable adverse impacts on the river base flow and groundwater
storage. Abstraction simulations for different scenarios of extremely severe
droughts reveal that it is possible to use groundwater to cope with the
droughts in the catchment. However, local groundwater exploitation in
Nelspruit and White River sub-catchment will cause large drawdowns
(> 10 m) and high base flow reduction (> 20%). This
case study shows that conjunctive water management of groundwater and
surface water resources is necessary to mitigate the impacts of droughts. |
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