Origin of salinity and hydrogeochemical features of porous aquifers from northeastern Guanabara Bay, Rio de Janeiro, SE - Brazil

Effects of a recent urbanization event on coastal groundwater in the southeastern coast of Brazil: a case study of the Macaé municipality

“…The pH and electrical conductivity were similar among the wells during the monitoring period. Such values were reported for coastal aquifers from the granitic-gneiss lithology and diverse regional geochemical facies, as also related to marine-derived atmospheric deposition and anthropogenic contamination (Silva-Filho et al, 2009;Gomes et al, 2019). For major ions, coastal groundwater from the shallow and deep wells had a predominance of Cl -, SO 4 -2 , Na + , Ca 2+ (Table 1) that should be attributed not only to the local granitic lithology and weathering, but also to the marine droplet atmospheric deposition, seawater intrusion and soil organic matter decomposition (Silva-Filho et al, 2009;CPRM, 2012).…”

“…Consequently, urbanization, especially rapidly developing cities, has increased coastal aquifer exploitation and the emission of a myriad of untreated effluents (Machiwal et al, 2018). In addition, coastal groundwater salinization may occur by intensive groundwater withdrawal, land subsidence, and seawater intrusion, allowing hydraulic saline gradients into aquifers (Hoover et al, 2017;Gomes et al, 2019).…”

“…Along the coastal plain, aquifers have important storage capacity, which might be influenced by surface and marine waters (Hu et al, 2017). However, the literature shows scarce data characterizing coastal groundwater pollution and salinization (Silva-Filho et al, 2009;Godoy et al, 2013;Mirlean et al, 2014;Bertrand et al, 2016;Paim et al, 2018;Gomes et al, 2019). Urbanization in several coastal cities has been intensified over the last 40 years, induced by the oil and gas industry, tourism, the naval industry, general services, and others.…”

“…Besides, more than half of the aquifers in Brazil are not regulated, adding unknown pressure on groundwater exploitation and water quality (Vilar, 2016). In this context, many studies have addressed the impact of megacities on groundwater (Bertrand et al, 2016;Gomes et al, 2019), but no studies have been described for small coastal cities, in which urbanization has been recently intensified, with unknown impacts on groundwater. Therefore, this study provides a seasonal and spatial groundwater chemical and microbiological characterization of coastal shallow and deep wells from sedimentary and fissured aquifers in a recently urbanized coastal region.…”

GUANABARA BAY: Proposals for a Territory of Exclusion Born from Paradise – Part II, For a Macro-Engineering Covenant (BAÍA DE GUANABARA: Propostas para um Território de Exclusão Nascido do Paraíso - Parte II, Por um Pacto de Macro-Engenharia)

“…As a coastal body of seawater body belonging to a country with severe eco-social disfunctions, nowadays GB is a watery cast-off aquatic waste-bin of unwanted and unneeded anthropogenic exogenous substances. Since even Petrobras and others [10] may not care much about the actual poisoning of the Bay by petrochemical emissions, spills and dumped infrastructure castoffs, nevertheless we still maintain the hope that, as a foreign researcher as well as a proud citizen, we can together establish and disseminate to the immediate region's despoliation-beset human community a doable mechanical means to rehabilitate that coastal landform whose current state of near-term social abandonment affects, at different levels, about ten million human beings, both Brazilians and visitors.…”