As geoformas e a estrutura vertical das paisagens da Ilha da Trindade, Atlântico Sul

Abstract

This study aimed to expand knowledge about the relief of Trindade island through the identification, mapping, and characterization of landforms, and their relationship with the soil, geological substrate and vegetation. An aerial photographic survey with drone was carried out; preparation of thematic maps (slope, vertical curvature, etc.), delimitation of landforms in the images, checkpoint control in the field, automated classification of the relief by machine learning technique, and preparation of geoecological profiles. Eight landforms were identified, being 4 erosive (slopes, ridges, plateaus,and necks) and 4 depositional/constructional (ramps in talus, alluvial cones, beaches and dunes / sand sheets). These landforms are inserted in four geomorphological compartments (summit, transition, coastal and crater), which, in turn, divide the island into two faces, eastern and western. In landforms there are linear features such as escarpments, paleophalies, ravines and drainage channels. The slopes represent the lansform with the greatest spatial expression, occupying 60% of the island, and reinforce the importance of erosion in the evolution of Trindade relief. The vertical structure of the landscapes reveals a control of the plateaus and alluvial fans in the development of weathered soils, and erosion in the slopes as drivers of the formation of young soils and herbaceous vegetation.