Analysis of the Recent Climatic Evolution in Burkina Faso (Upper Volta)

This paper analyses the recent climatic evolution in the Sahel, and more particularly in Burkina Faso (formerly Upper Volta). For this evolution, three stages can be recognized which go from a humid phase before 1950 to a dry phase after 1965. The main evidence of this evolution is the steady decrease in the number of rains exceeding 40 mm and the relative increase in the number of annual rains. It is suggested that rainfall of less than 20 mm constitutes the stable component of the rainfall. An analysis of the data available does not indicate an improvement in climatic conditions in the near future.