Cartographier les populations ou les sociétés ? Problèmes de représentations dans deux atlas en Afrique de l'Ouest

Mapping Populations or Societies , Perception Problems in two Atlases of West Africa. Through two examples of demographic atlases, the first one in Mauritania, the second in Mali, we had to select different types of information visualisation. Far from being only a problem of graphic language, these choices inferred also on the accuracy of the produced images. But making a scientific map is a specificity of our culture and our way of representing the world. The maps built from geographical data bases, within administrative limits may be only a visualisation of the population stocks at a census date without an approach of the social mobility and dynamics. By using the Euclidian geometry, the map expresses more a topographical metrics to visualise a society than a topological one. These two atlases gave rise to try different methods of cartography and assess the limits of others. The map is a collection of information which enlarges our individual perception but the use of a sémiologie code and the information processing for mapping have an impact on this image of the social reality. The cartographer and the user of the map, must keep a critical distance from this image of the reality. They must remember that the map is more the matter of the subject than of the object.