Hidroquímica e vulnerabilidade do Sistema Aquífero Barreiras na Bacia Hidrográfica do Rio Pirangi/RN

The study area is located in the Pirangi River Basin, Metropolitan Region of Natal, covering 370 km². The Barreiras Aquifer System (SAB) in the study area has high hydrogeological potential and the capture of its waters has been essential for the water supply of urban and rural populations and the i...

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Detalhes bibliográficos
Autor: Silva, Janaina Medeiros da
Formato: tesis de maestría
Estado:Versión publicada
Fecha de publicación:2020
País:Brasil
Recursos:Universidade Federal do Rio Grande do Norte (UFRN)
Repositorio:Repositório Institucional da UFRN
Idioma:portugués
OAI Identifier:oai:repositorio.ufrn.br:123456789/28899
Acesso em linha:https://repositorio.ufrn.br/jspui/handle/123456789/28899
Access Level:acceso abierto
Palavra-chave:Sistema Aquífero Barreiras
Bacia Hidrográfica do Rio Pirangi
Avaliação hidrogeoquímica
Qualidade das águas subterrâneas
Vulnerabilidade de aquífero à contaminação
CNPQ::CIENCIAS EXATAS E DA TERRA::GEOCIENCIAS
Descrição
Resumo:The study area is located in the Pirangi River Basin, Metropolitan Region of Natal, covering 370 km². The Barreiras Aquifer System (SAB) in the study area has high hydrogeological potential and the capture of its waters has been essential for the water supply of urban and rural populations and the industrial and agricultural development of the region. However, disordered urban growth and the adoption of inappropriate agricultural practices have threatened the quality of this underground spring. Based on the above, this study evaluates the hydrochemical behavior and water quality of SAB in the Pirangi River Basin region, as well as mapping the natural and anthropic vulnerability to aquifer contamination. The analyzes consider mapping of land use and occupation. For the hydrochemical study, a 30-well monitoring network was defined, followed by a collection campaign and physicochemical analysis of water samples. The interpretation of the results was made through isovalor maps and hydrochemical diagrams. Regarding water quality, groundwater was evaluated for human consumption, agricultural purposes and industrial use. The mapping of SAB vulnerability to contamination was performed by applying GOD, DRASTIC and IS methods based on the analysis and interpretation of 38 lithological profiles of wells distributed in the study area and cartographic data from previous works. Despite the hydrochemical variations observed in the different sectors, SAB groundwater in the study area is generally characterized as slightly acidic and of low salinity, predominantly encompassing magnesian sodium chloride (Na + - Mg2 + - Cl-) and chlorinated sodium facies. (Na + - Cl-). The climatic aspect is the main controlling factor of the chemistry of these waters, with the influence of anthropogenic factors of urban development and agricultural activities (nitrate contamination). As for quality, 70% of the samples evaluated can be destined for human consumption; for agricultural purposes there is no restriction on use; and for industrial application there were mainly restrictions on the paper, textile, beer, dairy and canning industries. The mapping of vulnerability to SAB contamination resulted in a predominantly low and intermediate vulnerability index for the urban zone through the GOD and DRASTIC methods and an intermediate index through the IS method. In the areas of agricultural development and in the area of lagoons and dunes with little human intervention, low and intermediate vulnerability indices were determined using the DRASTIC and IS methods, while the GOD method has a predominance of high vulnerability.