LITHOSTRUCTURAL CONTROL OF THE PIRANHAS-AÇU WATERSHED DRAINAGE, RIO GRANDE DO NORTE, NORTHEAST BRAZIL

Abstract

The lithostructural control of the drainage network of the Piranhas-Açu river basin was investigated through the correlation of lithological, tectonic, geomorphological and density data and direction of structural lineaments, in addition to drainage patterns and anomalies. The research stages began with a bibliographic and cartographic review of the lithostructural and geomorphological context of the area, followed by fieldwork and the use of GIS tools. From the use of GIS, the work used the DEM NASADEM HGT (2000), with a spatial resolution of 30 meters, which allowed the extraction of the drainage network and the deformation structures, as well as the identification and distribution of drainage patterns. Quantitative results indicate median drainage density and predominance of dendritic and subdendritic drainage patterns, but with occasional occurrences of drainage patterns indicative of lithostructural control, with emphasis on parallel, parallel/rectangular, centrifugal radial and trellis patterns. Additionally, there is an abundance of anomalies suggestive of lithostructural control, including straight stretches, drainage elbows, straight angle junctions and superimposition and avulsion processes.