Identificação e classificação de formas de relevo tecnogênicas produzidas pela extração de areia e sal no município de Cabo Frio (RJ)

Abstract

The municipality of Cabo Frio, nestled in Rio de Janeiro's Coastal Lowlands, has undergone profound changes due to rapid urbanization and landscape transformation, largely driven by tourism and real estate development. This has led to the emergence of sand extraction pits and salt extraction ponds as prominent features resulting from historical land use and resource exploitation. This study aims to comprehensively assess changes in land cover and land use within Cabo Frio, with a particular focus on the impacts of sand and salt extraction activities. Remote sensing data spanning from 1984 to 2022 were utilized for this analysis. The methodology involved a five-stage process, employing Landsat 5 and 8 remote sensing imagery alongside digital image processing through Geographic Information System (GIS) tools. Quantum GIS (QGIS) served as the primary analytical tool, supplemented by the Semi-Automatic Classification Plugin (SCP). Through this approach, sand extraction pits and salt extraction ponds were classified as excavation technofacies, representing human-induced alterations to the landscape. The findings of this research reveal a decrease in water bodies and a reduction in fields, pastures, unconsolidated sediments, and saline areas, primarily attributed to the rapid expansion of urban areas encroaching upon these natural features. Conversely, dense vegetation cover has shown significant growth, particularly over the past decade. Notably, sand extraction witnessed a substantial increase between 1995 and 2005, with current trends indicating a slower rate of expansion. This study provides valuable insights into the dynamic interplay between human activities and natural landscapes in Cabo Frio, highlighting the urgent need for sustainable land management practices to mitigate further environmental degradation and preserve the region's ecological integrity.