Análise das transformações morfológicas e ambientais em sistemas dunares no município de Cabo Frio, RJ

Abstract

The study “Analysis of morphological and environmental transformations in dune systems in the municipality of Cabo Frio, RJ” analyzes changes in the morphology of free and semi-fixed coastal dunes in the coastal plain located south of the cape Frio – cape Búzios compartment. The motivation for this research lies in the great importance of this region for the state of Rio de Janeiro, as it is considered an exceptional area due to its climatic characteristics and the presence of eolian geomorphological features, which have attracted the interest of several scientists. Previous studies have observed significant changes in the morphological behavior of these features, reinforcing the relevance of this research. Thus, the objective of this study is to analyze the morphological changes in these dunes and relate them to transformations in the Cabo Frio landscape, such as vegetation expansion, climate changes, and alterations in land use and land cover. Using mapping techniques such as photointerpretation and aerophotogrammetric surveys, conducted on images from multiple acquisition platforms between 1959 and 2024, significant changes were observed in these coastal features and their surrounding environmental conditions. Initially, the area was characterized by a transgressive sand sheet. However, over time, it underwent fragmentation and evolved into individualized eolian features, such as barchanoid dunes, barchans, nebkas, parabolic dunes, and the mega-parabolic dune. The mappings also revealed significant changes in land use and land cover, with the replacement of coastal dunes by urbanized areas, leading to the fragmentation of the dune field. Another relevant aspect was the significant expansion of vegetation, which played a crucial role in stabilizing the dunes and influencing the sedimentary dynamics of the coastal plain. The study also investigated whether this vegetation expansion is related to changes in the region's climatic behavior by correlating vegetation cover data with variables such as maximum temperature, minimum temperature, precipitation, and wind speed. Finally, this research initiates three-dimensional analyses of the mega-parabolic dune, contributing to future investigations on the preservation status of this feature, which is highly relevant to the studied coastal plain.