Répartition des ressources et des demandes en eau dans le monde : Disparités présentes et futures

World distribution of water resources and demand. Present and future disparities

BRGM

Abstract

Water resources and their use are both very irregularly distributed throughout the world. The available statistics and the macroscopic indicators deriving from them can show this irregularity in tables and maps. * Water resources are linked to the climate that generates them and on physiographic features that distribute them. Use is equally controlled by climate, but even more so by the degree of development of the user ; in the first case, variations in use can vary with a factor of 1000, and variations in development level can cause water use variations with a ratio of up to 1: 100. * These disparities are likely to become worse in the future. The rapidly decreasing resources per person, caused by a rapidly increasing population, may pose limits to satisfying the growing requirements that are caused by development pressure. Another outcome of this increasing scarcity is, that in some regions the terrestrial stages of the water cycle will be artificially prolonged.