Innovative Evaluation of Field and Spatial Remote Sensing Data for Analysis of Vegetation Bio-types in Arid Rangelands, Taznakht, Moroccan Anti-Atlas

Abstract

In Morocco, as in many other regions of north Africa, desertification is affecting the most sensitive environments such as the rangelands. Demographic expansion, cereal growing, and overgrazing constitute the principal factors of degradation in such regions. The use of satellite data provides an efficient tool for observation and continuous measurement of the biosphere. Our objective is to propose a method for the characterization and mapping of rangelands in arid and desert areas, based on the biophysical reality of the environment (field data). A highly detailed study based on field surveys of the Taznakht basin (Moroccan Anti-Atlas) was carried out to determine rangeland typology. Close relationships were demonstrated between the abiotic environment and the vegetation. The relevant bio-pedo-morphological classes at each site, corresponding to the different types of rangeland, were identified. The cartographic accuracy of these classes was considerably increased by combining the stratification obtained by Visual Interpretation Assisted by Computer of the photofacies of a Satellite Pour l'Observation de la Tene (SPOT) image obtained during the dry period, with a supervised classification of each stratum based on maximum likelihood. This methodological approach was used to develop a simple, robust, and generally applicable model for the efficient correlation of field and remote sensing data.