Caracterização hidrogeológica utilizando o método da eletrorresistividade na Comunidade Apolinário, município de Curuá - PA

Abstract

The research was conducted in the municipality of Curuá, in the Santarém microregion of Pará, with the Apolinário community, approximately 26 km from the municipal center, as the study area. The objective was to conduct a hydrogeological study to assess the quality and availability of local water resources. The geophysical method of electrical resistivity, applying Vertical Electrical Sounding (VES) and Electrical Traversing (CE) techniques, was used to identify geological formations and the presence of groundwater. Physicochemical and bacteriological analyses of the water were also performed, in addition to flow tests in a tubular well and in the Mamiá River. Two VES profiles were conducted to assess resistivity at depth, identifying four layers: residual soil, Alter do Chão Formations, Nova Olinda Formations, and Penatecaua magmatism. The two CE profiles revealed three layers, allowing the distinction between saturated, capillary, and unsaturated zones, as well as the contacts between soil and geological formations. The CE results confirmed those of the SEVs, expanding our understanding of the lateral structure of the subsurface. Analyses of the Mamiá River revealed values above the limits for human consumption for total and thermotolerant coliforms, turbidity, total iron, and apparent color. In the groundwater, coliform contamination was identified in wells 1, 2, 3, 5, 6, 7, and 8; well 5 presented high apparent color, and well 2 presented turbidity above the permitted level. The Mamiá River flow rate was 17,733 L/s, and well 2, 2.23 L/s. Therefore, the use of wells 1, 2, 3, 6, 7 and 8 without treatment is not recommended, and the drilling of new wells is not recommended, due to the salinity and high electrical conductivity observed in well 2. It is recommended that the flow rate of the wells be monitored throughout a hydrological year and that a professional in hydraulic engineering be hired to study the feasibility of using the flow of the Mamiá River to supply the community.