Resumo

FAGUNDO-CASTILLO, Juan R.; ALCONADA-MAGLIANO, Margarita M.; CARRILLO-RIVERA, J. Joel  e  GONZALEZ-HERNANDEZ, Patricia. Characterization of Groundwater Flows according to Salinity. Tecnol. cienc. agua [online]. 2014, vol.5, n.3, pp.63-80. ISSN 2007-2422.

The relationships among elements in the landscape can be explained using the theory of groundwater flow systems, which recognizes the different flows and their discharge and recharge zones, demonstrating their hydrological functioning. Characterizing the different flows is crucial to identifying their potential, salinity and possible use for different agricultural and forestry management practices. This definition implicitly includes characteristics related to quantity and depth of circulation. In environments where the water table is shallow, defining flow is key to selecting agricultural and forestry management practices that help in a given situation, such as water excess or deficit. The flows are defined according to the water quality and environmental indicators. The costs of the chemical analysis of water are high and it is difficult to analyze large areas. Nevertheless, electrical conductivity (EC) can be used to estimate the chemical composition of water in an area if the principles through which they acquire their composition are known and mathematical relationships with major ions are determined. The objective of the present study is to determine the feasibility of using the proposed hydrogeochemical models to calculate the chemical composition of water based on its electrical conductivity. Sources of water from wells, phreatimeters and lagoons in northwest Buenos Aires, Argentina were studied to identify the geology of the site and apply hydrogeochemical pattern recognition models to identify patterns (HIDROGEOQUIM, GEOQUIM, SAMA, MODELAGUA). The hydrogeochemical patterns and mathematical relationships between the ionic composition and EC were obtained. The best fit was obtained using the polynomial (parabola) equation that passes through the origin of the coordinates, having previously grouped the data using the pattern recognition model. It is concluded that the chemical composition of the water can be defined with mathematical calculations based on the value of electrical conductivity, which along with pH, temperature and other elements of the landscape enable defining types of flow and related soil management.

Palavras-chave : Groundwater flows; electrical conductivity; water quality; recharge; discharge; soil management; landscape; shallow phreatic surface.