Evidências de controle estrutural na sub-bacia do Alto Acaraú - CE.

Abstract

The relief of the Northeast of Brazil exposes to superficial levels several evidences of tectonic activities, structurally controlled morphologies and the occurrence of post-Cretaceous epirogenesis, succeeded by phases of dissection and pediplanation. These structural characteristics overlap the drainage network by controlling the configuration of its arrangement. The present research pursued analyze structural control evidences in the configuration of the drainage network of the Upper Acaraú Sub-basin, focusing the profile of the main channel of Acaraú River among the Serra das Matas Crystalline Massif and Açude Araras, as from the components of the relief. The development of this research assayed an analysis of the drainage network through the application of index calculations to determining of the drainage density, the hydrographic density and the sinuosity, furthermore the observation of channels management, through the crossing of the elevation model with the studied area hydrography layer, generating a thematic mapping. The analysis of interpolation of the geological data using SRTM image evidenced the structural influence in the spatial arrangement of the fluvial channels. These mapped elements were supported by several published studies on the geological compartmentation units that cover the study area. The application of geoprocessing tools, such as remote sensing, were fundamental for the elaboration of the products that resulted in the basis of the outcomes. At the end of the research, it is concluded that conditioning factors, such as the lithological difference, associated with the structural configuration and the climate, display conspicuous evidences of structural control, important to understanding the geomorphological evolution and channel arrangement in the drainage network of the Upper Acaraú Sub-basin.