International audienceThrough an agent-based model, this presentation will detail the implementation steps and representation choices that have to be made for the simulation of coastal urban population in a case of tsunami in St-Laurent-du-Var (Côte d'Azur, France). At the core of the simulation, the urban aspect of the area with issues of visibility for the itinerary of evacuation dealing with buildings as obstacles for agents, and of practicability of the street space in case of a forerunning earthquake which can make some buildings collapse and obstruct the path. The environmental structure constrained the GIS implementation, as did dynamic aspects, which led to thinking over representation choices according to model perspective.Cette co...