Optimistic Scenario of 0.50 m Mean Sea Level Rise and Possible Environmental Impacts, Resulting from Tidal Variations, in the City of Niterói, Rio de Janeiro—Brazil

As several researches indicate, since the 1950s one observed unprecedented warming of the atmosphere and oceans, resulting from greenhouse gas emissions and changes in land use and occupation, leading to sea level rise and impacts on coastal areas. In the municipality of Niterói—Rio de Janeiro, Brazil, where a large urban concentration in coastal areas is observed, a Climate Change Adaptation System was developed, through which mitigation and adaptation strategies are combined, in order to: reduce vulnerabilities; avoid losses and damages; build instruments to allow adaptation of natural, human, productive and infrastructure systems. In this context, this paper aims to measure possible impacts, in the biophysical and socioeconomic spheres, resulting from an eventual 0.50 m rise in mean sea level, which represents an optimistic scenario according to the National Oceanic and Atmospheric Administration. In contrast to similar studies, this work also considered daily and occasional water level variations, represented by the highest astronomical tide and the highest storm surge observed in the studied region. The following data were applied: digital elevation model, 2010 population census data, and real estate information. With the altimetry data, by means of GIS, the census sectors inserted in the affected areas were selected, to obtain data regarding population, number of households, and income. Specialized websites were applied to collect average property values. The simulations revealed that approximately 2950 households and more than 9000 residents could be directly affected, with losses that could exceed R$ 3.60 billion. The Oceanic Region is configured as the most exposed region, susceptible to losses of several ecosystems, economic losses in residential areas and possible destruction of urban infrastructure.