Modifying forestry and agroforestry to increase water productivity in the semi-arid tropics.
The need to increase water productivity is a growing global concern as the World Commission on Water has estimated that demand for water will increase by c. 50% over the next 30 years and approximately half of the world's population will experience conditions of severe water stress by 2025. Three-quarters of African countries are expected to experience unstable water supplies, whereby small decreases in rainfall induce much larger reductions in streamflow.