  In an emergency situation, the actors need an assistance allowing them to
react swiftly and efficiently. In this prospect, we present in this paper a
decision support system that aims to prepare actors in a crisis situation
thanks to a decision-making support. The global architecture of this system is
presented in the first part. Then we focus on a part of this system which is
designed to represent the information of the current situation. This part is
composed of a multiagent system that is made of factual agents. Each agent
carries a semantic feature and aims to represent a partial part of a situation.
The agents develop thanks to their interactions by comparing their semantic
features using proximity measures and according to specific ontologies.
