Geovisualizing land degradation risk in Southeast Brazil Using remote sensing and GIS-based assessment

Land degradation poses a critical threat to ecosystem services and sustainable development, especially in regions experiencing rapid land-use transitions. This study employs an integrated geospatial approach-combining remote sensing, geographic information systems (GIS), and spatial multi-criteria analysis-to assess and visualize land degradation risk in a strategic coastal region of southeastern Brazil (Rio de Janeiro State). Using the United Nations Environment Programme's Priority Actions Programme Regional Activity Centre (UNEP-PAP/RAC) framework applied to recent satellite imagery, we generated spatially explicit maps classifying land into stable and unstable categories. A geospatial prioritization model incorporating biophysical and socio-economic variables was developed to identify conservation hotspots and support decision-making. Results show that 68.4% of the landscape is stable, largely consisting of unmanaged areas with agricultural and forest potential, while 7.8% is unstable, with sheet erosion concentrated at agricultural frontiers. Priority mapping classified 51.7% of the area as Stable Medium Priority, revealing widespread latent vulnerability, and 4.6% as Unstable High Priority, necessitating urgent intervention. Complementary analysis of land-use change (1985-2024) highlighted a 199% urban expansion and a 34% decline in agricultural mosaics, underscoring anthropogenic drivers of degradation. This study not only validates the PAP/RAC framework in a humid tropical coastal setting but also delivers actionable geovisualization outputs and a spatial decision-support tool for targeted land management, contributing to soil conservation and sustainable development policy in Brazil.