Popis: |
The semi-arid southern piedmont plain in the Algerian Saharan region is characterized by dayas, i.e. small semi-circular depressions colonized by vegetation. These dayas show specific morphological variations and vegetation characteristics. A correlation was noted between their morphology, vegetation cover and stage of development. Thus, it is of interest to develop an approach for combining the vegetation and shape criteria within a feature vector of each pixel to map the dayas. Vegetation and geometrical properties concerning these day a structures, as determined from remote sensing data, were used in this work to perform chronological classification of all dayas in this region. The differential morphological profile and pattern recognition parameters are used for extraction and classification of the dayas formation on Land sat Thematic Mapper imagery. Each class corresponds to a specific morphological and vegetation evolution stage. |