Identification of depositional landforms in environment of confluence of the Branco and Grande rivers, west region of Bahia State (Brazil): by trend surface

ABSTRACT

The geomorphological understanding may lead to the evolution understanding and the processes that characterize the fluvial view at the Quaternary. Changes that happened in the fluvial systems are registered at the terraces and fluvial areas. In this way, the confluence stretch of the Branco and Grande rivers has paleochannels, abandoned meanders and lakes that denote the evolution of both channels. Therefore, this study aims to understand how these geomorphologies are placed in the area using as a resource provided by the remote sensing. It was used then the Shuttle Radar Topography Mission image in order to apply the trend surface model, which shows the light flotation of the area, in other words, positive values – high spots in the relief, and negative values – low spots. Through this observation, it was possible to identify the terraces and the areas of the low plain. The results were also described by the morphostratigraphic analysis that is important in order to validate the data applied by the geoprocessing analysis. Besides, the data inferred in the elaboration of a morphologies base chat placed in the fluvial portion.

KEYWORDS:

• Confluence
• trend surface
• depositional landforms