DISTRIBUTION OF SUPERFICIAL CORAL AREAS IN THE ARCHIPELAGO LA ORCHILA (VENEZUELAN CARIBBEAN) USING GEOMATHIC TOOLS

This work was carried out to determine the distribution of shallow bottom corals at the archipelago of La Orchila (Venezuelan Caribbean) using geomathic tools, through the analysis of multispectral images (SPOT 5) and using spatial navigation tracks. Thirty one coral zones were detected and validated by field work. In each of these areas, the marine bottoms were described and associated with in situ trial polygons in order to obtain their spectral signatures. Data were processed by specialized software in GIS and multicriteria analysis. The results showed spatial differences at the leeward zone, determined by the presence of corals of the genera Acropora, Porites, Millepora, Montastraea and Diploria, as well as species of Zoantharia (Palythoa), Octocorallia, seagrass (Thalassia), green algae (Halimeda), brown algae (Phaeophyceae), dead corals and sandy bottoms. Also, the spectral signatures of dead coral areas, sponges and calcareous algae and brown algae were determined (precisions of 100, 95.45 and 89.7% respectively). The remaining signatures were not determinant (