Socially-driven risk in a town of the Amazon coastal zone: the case of Vigia de Nazaré, in Pará state, Brazil

Vigia de Nazaré is a town located in the northeastern extreme of the Brazilian state of Pará, in the Pará Coastal Zone, a sub-region of the Amazon Coastal Zone. The town sits on the lower levels of the region’s terraces, and on fluviomarine plains. The different stages of its sociospatial evolution reflect the problem analyzed here, in particular, the occupation and urban development of the fluvial-marine plains, which was occupied spontaneously by large numbers of families, most of which are socially vulnerable. The present study investigated the physical and social processes that led this urban space’s vulnerability to hydrometeorological hazards, based on an integrated historical-geographic approach and the inherent precariousness of the environment. The data analysis revealed high levels of annual precipitation in the region, with a well-defined rainy season between January and May (mean monthly precipitation of over 300 mm), in an environment dominated by semidiurnal macro tides with amplitudes of up to 4.5 meters. In 2022, the high tide reached at least 4.2 meters in 60 occasions — the level of alert for possible rainfall-induced tidal surges. The recent occupation of the urban zone is concentrated on the low-lying areas of the fluviomarine plain, which recently account for one-third of the urban center. These areas are exposed to the hydrological dynamics of the local estuarine environment, which result in environmental degradation and hydro-morphodynamic processes alteration.