Forty Years of Landscape Transformation: Spatio-Temporal Dynamics and Land Degradation Vulnerability in Northeastern Rio de Janeiro, Brazil

Land degradation remains a critical challenge in Brazil, driven by historical deforestation and intensifying anthropogenic pressures. This study presents a geospatial assessment of land degradation risk and conservation priorities in northeastern Rio de Janeiro State, utilizing a modified UNEP-PAP/RAC framework. We integrated very-high-resolution (< 1m) Airbus imagery with multi-temporal Land Use and Land Cover (LULC) data (1985–2024) from MapBiomas to analyze landscape stability and transformation. Results indicate that while 66.66% of the area is stable, 25.77% is actively degrading, with rill erosion (16.31%) dominating the undulating Northwest Fluminense terrains. The assessment classifies 44.11% of the territory as High Priority, requiring immediate curative measures for eroded pastures and preventive protection for Atlantic Forest and Restinga fragments. The 39-year LULC analysis reveals a profound transition, marked by a 115.8% urban expansion and a 70.6% increase in temporary crops at the expense of traditional mosaic uses and fragile coastal ecosystems. These findings underscore a critical "tipping point" for regional land health and provide a robust scientific basis for integrating geospatial monitoring into sustainable land management policies and municipal planning.