


Photos: David Brazier, Akissa Bahri, Tom Van Cakenberghe
Sources:
Gleick, P. H., 1996: Water resources. In Encyclopedia of Climate and Weather, ed. by S. H. Schneider, Oxford University Press, New York, vol. 2, pp.817-823.
Groundwater and Human Development: Challenges and Opportunities in Livelihoods and Environment
Tushaar Shah, International Water Management Institute http://publications.iwmi.org/pdf/H035884.pdf
Environmental Research Letters Volume 7 Number 2,
A M MacDonald et al 2012 Quantitative maps of groundwater resources in Africa
A M MacDonald, H C Bonsor, B É Ó Dochartaigh and R G Taylor
http://iopscience.iop.org/1748-9326/7/2/024009
1 Surveys carried out by British Geological Survey and University College London