Urban expansion and environmental degradation in Boa Vista, Brazil

A case study of the urban stretch of the Cauamé river

Abstract

This article analyzes land use and land cover in the surroundings of the Cauamé river, located within the urban perimeter of Boa Vista, Roraima, with an emphasis on anthropic pressures on Permanent Preservation Areas (APPs). Based on the interpretation of Landsat 8 satellite imagery and the use of geoprocessing techniques, thematic maps were produced to identify the main spatial patterns of occupation and vegetation cover. The results indicate that, although the region still retains significant native vegetation – particularly savanna and riparian forest types – it is undergoing a gradual degradation process. This process is driven both by formal urbanization – exemplified by legally approved residential developments near the riverbanks – and by the expansion of informal settlements in environmentally fragile areas. NDVI analysis revealed a loss of vegetation vigor in urban fringe zones, especially in transitional areas between consolidated city sectors and zones of expansion. The study demonstrates that land occupation in Boa Vista occurs in a fragmented and uncoordinated manner, disregarding the ecological thresholds of the territory and compromising the integrity of urban water bodies. The findings highlight the need to strengthen urban planning and environmental management instruments – such as ecological-economic zoning and urban watershed management plans – to reconcile the right to housing with the protection of common environmental goods.