Abstract : "Territorie at risk" are spatial objects defined by the accumulation of events from risks (floods, landslides, etc.) through history. Interest in these events, from archival research to the establishment of observatories, has resulted in information dedicated to events (IDE). This information though, presents certain specificities (multidimensions, for example) and few tools permit its consultation in an organized and complete manner, in spite of the strong demand from the risk prevention and forecast sector. The value of IDE must therefore be better appreciated. The hypothesis that we are attempting to validate is that classical cartography (static maps and more sophisticated mapping (moving maps), interactive maps and multimedia maps) are limited on the Web. It is therefore necessary to extend the bertinian'semiology and to use new methods and techniques which refer to interactivity, dinamics displays, multimedia and visualization, offers to Web environment, in order to satisfy the needs of the actors involved (in terms of consultation of information). Each method and technique bring solutions, but they also reveal new problems. It is taking the strengths of each of them that brings us closer to proposing a dynamic cartographic visualization and multimedia which represent IDE. To validate, this proposal, on one hand, it would be integrated into a knowledge discovery tool, a type of SIHREN (Information System Dedicated to Risks and the History of Natural Events) and on the other hand, its effectiveness in terms of meeting the needs of actors and specificities of IDE, is tested.