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Titre : Groundwater as an emergency source for drought mitigation in the Incomati River basin - case study of the Crocodile river catchment

Auteur : Mussa, F.E.F.

Université de soutenance : UNESCO-IHE Institute for Water Education, Delft

Grade : Master of Science (MS) 2013

Résumé partiel
Global climate change has received much attention worldwide in scientific as well as in political community, indicating that changes in precipitation, extreme droughts and floods may threaten many regions. Droughts are natural hazards that cause social, economical and environmental damages. Governments and affected population are engaged in strategic measures by means of local limited capacity and knowledge as well as by receiving external support, for example to enhance the predictions and early warnings. The lack of knowledge regarding the quantification of variability and changes in the hydro-climatic extremes, changes in hydrology and possible adaptation strategies remain as major obstacles in minimizing the damages to the society caused by thenatural disaster. This research aims to study the trends in dry extremes and the use of groundwater as a supplementary source of water to mitigate the drought impacts in the Crocodile River catchment, a sub-catchment of the Incomati River basin. The research methodology consists mainly of four parts. Firstly, trend detection on the annual precipitation, annual discharge and dry extreme parameters of precipitation and discharge was carried out by means ofthe CUSUM (Cumulative Sum Charts) and Regime Shift Detection methods to detect trends. Secondly, the spatial and temporal variation of the meteorological and hydrological drought severity and intensity over the catchment was evaluated. The Standardized Precipitation Index (SPI) was used for the meteorological drought and the Standardized Runoff Index (SRI) was used for the hydrological drought. Afterwards, the water deficit in the catchment in the droughts period was computed by using a simple surface water balance method. And finally, a groundwater model using MODLFOW software was built in order to assess the possibility of using groundwater as an emergency source of water to mitigate the drought impacts in the catchment.

Sujets  : groundwater drought river basins precipitation case studies

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