Fluvial Dynamics in Brazilian Semiarid: Morphostratigraphy and Evolution of Unchanneled Landscapes

Abstract

This work sought to elucidate the evolution of unchanneled landscapes in the Borborema Plateau, Northeast of Brazil, by means of the application of a morpho-stratigraphic approach. To contribute to the understanding of the contemporary surface dynamics, with the help of drones detailed geomorphological mappings were constructed
applying digital techniques of image restitution and the assemblage of georeferenced orthomosaics. The products obtained, on a scale of 1: 2,000, constitute a tool and a starting point for the recognition of the formative events that originated the deposits that now structure the unchanneled morphologies. The mapping revealed that there is a strong anthropogenic component in the creation of accommodation spaces, through the interposition of artificial dams to the channels that drain from the highest areas of the Plateau’s. These accumulation units, ubiquitous over the regional landscape, play a fundamental
role in the dynamics of the traditional agrarian landscapes of the northeastern semiarid.