Abstract
The present availability of powerful calculation means and the geographical data bases allow to get beyond the simple statistics in order to solve the hydrological problems in assessing the water resource and in predetermining the floods. In conjunction with rain generators, some modelizations of the rain into discharge are able to generate continuous long chronicles of discharge and flood hydrograms. Theses chronicles are then available to take up different problematics: comparison resource-need, water reservoir management rules, project flood... The use of simple models allows to catch sight of real opportunities of regionalisation and integration into some geographical information systems as well as simulation opportunities of the impacts liked to anthropical activities.