Résumé: The paper presents a topology- based visualization method for time- dependent two- dimensional vector .elds. A time interpolation enables the accurate tracking of critical points and closed orbits as well as the detection and identi .cation of structural changes. This completely characterizes the topology of the unsteady .ow. Bifurcation theory provides the theoretical framework. The results are conveyed by surfaces that separate subvolumes of uniform .ow behavior in a three- dimensional space –time domain.

Langue: Anglais