Mapping categories of gypseous lands in Mexico and Spain using Landsat imagery

Remote sensing is a powerful tool for thematic mapping, but its use for the discrimination of different kinds of soils has been scarce and the results variable. We demonstrate the usefulness of Landsat ETM+ images to discriminate gypseous lands in two contrasting regions, Cedral, Mexico, and Bujaraloz, Spain. We also discuss the contribution of the infra-red bands, and found the bands of mid and thermal infra-red to be the more useful. A supervised classification of Landsat ETM+ images enabled us to discriminate land covers related to gypseous lands in Cedral, and to locate gypsum lithologies in Bujaraloz. The thermal infra-red band does not substantially improve the classification in Bujaraloz, but it does in Cedral, being best in the wet season, when the differences of temperatures among classes are relevant.