The Dezert - Smarandache Theory (DSmT) used for the fusion and the modeling of the classes sets of themes has shown its performances in the detection and the cartography of the changes. Moreover the contextual classification with the research for the optimal solution by an ICM (Iterated conditional mode) algorithm with constraints allows to take in account the parcellary aspect of the thematic classes, thus, the introduction of this contextual information in the fusion process has enabled us to better identify the topics of surface and the detection of the changes.