Análise morfológica do relevo da bacia hidrográfica do Jeniparana, ilha do Maranhão

Abstract

The study aims to analyze the morphological characteristics of the relief of the Jeniparana River hydrographic basin through the characterization of the geoenvironmental aspects of the basin, analysis of the relief compartments of the study area, and understanding of the slope characteristics. The methodological procedures adopted involved two stages: office work and field analysis. The geomorphological mapping methodology of the Jeniparana River basin was divided into stages. Firstly, the cartographic survey used data from the “Geodiversity of Maranhão Island” project and planialtimetric maps from the 1980s, which allowed the vectorization of contour lines, drainage, and spot heights. As a result, thematic maps of geology, pedology, and geomorphological compartments were developed, which were essential for the spatial analysis of the basin. The analysis of satellite images helped identify morphologies and erosive processes. Topographic models were used to measure the depth of dissection and define the landforms. The final stage, the fieldwork carried out in April 2024, focused on validating the previous analyses by collecting coordinates, altitudes, and photos via GPS. The comparison of field data with cartographic and satellite analyses allowed for a precise and detailed characterization of the relief compartments of the basin. The Jeniparana River hydrographic basin, located on Maranhão Island, features fluvial plains, tidal plains, supratidal plains, slightly dissected and highly dissected tablelands, and hill forms. The geomorphological compartmentalization was based on the verification and validation of hypsometric products (with altimetry varying every 5 meters) and slope characteristics (ranging from 0 to 30%) in the study area, in addition to pedological confirmations (classified as Dystrophic Red Argisols, Dystrophic Red-Yellow Argisols, Haplic Gleysols, Orthic Quartzarenic Neosols, Undifferentiated Mangrove Soils, and areas with high urban density) and geological characteristics (such as Barreiras Group, Alluvial and Colluvial Deposits, and Mangrove Deposits). The cartographic products during laboratory activities were prepared using QGIS Desktop v 3.28.10 and corrected within the same software