Hydrological drought forecasting in Africa at different spatial and temporal scales; Dissertation, UNESCO-IHE Institute for Water Education, Delft and Delft University of Technology.

Africa has been severely affected by droughts in the past contributing to food insecure conditions in several African countries. In view of the (even more) severe drought conditions and water shortage that may be expected in the coming years in sub-Saharan Africa, efforts should focus on improving drought management by ameliorating resilience and preparedness to drought. This study contributes to the development of a modelling framework for hydrological drought forecasting in sub-Saharan Africa as a step towards an effective early warning system. The proposed hydrological drought forecasting system makes use of a hydrological model that was found to be suitable for drought forecasting in Africa and could represent the most severe past droughts in the Limpopo Basin. The modelling results showed that there is an added value in computing indicators based on the hydrological model for the identification of droughts and their severity. The proposed seasonal forecasting system for the Limpopo Basin was found to be skilful in predicting hydrological droughts during the summer rainy season. The findings showed that the persistence of the initial hydrological conditions contribute to the predictability up to 2 to 4 months, while for longer lead times the predictability of the system is dominated by the meteorological forcing.An effective drought forecasting and warning system will hopefully contribute to important aspects in the region such as water security, food security, hazard management, and risk reduction