Classification dirigée de données de télédétection radar et d'un modèle numérique d'altitude pour la cartographie des formations meubles dans la région de l'Abitibi, Québec

Abstract

A large proportion of Québec and Canada is uninhabited and located in a boreal environment. Maps of superficial deposits of these regions are often produced at small scales, resulting in poor precision. Some studies have proved the utility of radar images for Quaternary mapping. The use of a Digital Elevation Model (DEM) may also be advantageous.A supervised classification has been performed using textural features from the radar scenes and a DEM on a test site in theAbitibi region in Quebec. The study is based on the fact that the vegetation cover affects the radar backscatter, and that topographic changes on a relatively flat terrain illustrate the distribution of surficial deposits. Comparison between the improved base map of surficial deposits and the classification results shows 65 to 70% similarity. Texture analysis proved to be essential for better discriminating certain classes. These are encouraging results, however, the remaining 30 to 35% inaccuracy can be explained by mainly two factors. First, we were unable to perform perfect geobotanical associations because of the difficulty in discriminating forest types by C-HH radar data. Second, the association between the slope and the surficial deposit was also imperfect.