Published for managers, experts, researchers, professors, students, pupils, and general public, this 1:6,000,000 reference poster-map of mean annual rainfall has been updated on a recent homogeneous 39-year period, and concern 23 West African states, integrating data from 890 raingauge stations, including the 230 WMO synoptic stations.
An attached map presents the southern slide of the mean annual 250, 500, 1000 and 1500 mm rainfall lines between 1951-1969 and 1970-1989, showing a persistent rain shortage since around 1970.
Original data come, for 13 French-speaking countries except Guinea and Zaïre, from daily data annals. These annals are available from are avai

lable at the Publishing Department of ORSTOM for period between beginning and 1965, and from Hydraulic Ministry or Meteorological Department of each country, or Ecole Inter Etats d'Ingénieurs de l'Equipement Rural (B.P. 7023, Ouagadougou) for the 1966-1980 period.

The corresponding digitized records can be obtained from ORSTOM (Laboratoire d'Hydrologie, B.P. 5045, 34032 Montpellier, France), according to each country distribution policy. The data of the 1981-1989 period and those of 8 other countries can be obtained from National Meteorological Departments. In the future, the numerical data should be available on a server, depending on the agreement of each country. In a first time and for test purposes, data of Benin should be available.