Much of Africa experiences very high hydrological variability in all components of the water cycle, with important implications for people and ecosystems. Most of the continent's water is stored in groundwater , which is 20 times more than the water stored in the lakes and 100 times more than the annual renewable water resources . The accessible volume of groundwater via wells and springs is smaller than these estimates . Africa has 63 transboundary river basins , 72 mapped transboundary aquifers  and 33 transboundary lakes , reflecting a highly water-connected and interdependent socio-ecological system across countries, also extending to the coastal areas of the continent .
IPCC
Climate Change 2022: Impacts, Adaptation and Vulnerability
IPCC Report