Temporal analysis of land use and land cover in the Soledade river basin, PB

Abstract

The Rio Soledade hydrographic basin, located in a semi-arid region of Brazil, has been the stage for significant changes in its landscape, driven by anthropogenic pressures such as agricultural expansion and inadequate soil use, added to the effects of climatic oscillations like prolonged droughts. This study analyzed the dynamics of the basin's vegetation cover between the years 1985 and 2025, using the Normalized Difference Vegetation Index (NDVI), derived from satellite images. The hypothetical results indicated a general trend of reduction in average NDVI values over the decades, with emphasis on the expansion of exposed soil areas and the fragmentation of denser vegetation formations. Initially, in 1985, more robust Caatinga formations predominated, with NDVI values indicating dense vegetation. However, from 2005 onwards, and more accentuated after 2015, a progressive degradation of vegetation cover is observed. The analysis of the maps showed that the areas with the greatest vegetation loss would be concentrated in the portions of the basin with greater agricultural activity and close to urban settlements, indicating the direct influence of human activities. The decrease in NDVI reflects the substitution of shrub-tree formations by low-lying vegetation or exposed soil, evidencing the impact of unsustainable agricultural activities and the basin's vulnerability to adverse climatic conditions. NDVI, in this context, proved to be an essential tool for monitoring environmental degradation, allowing for the identification of critical areas and the understanding of spatial and temporal patterns of vegetation cover loss.