Análise multivariada dos parâmetros de qualidade das águas subterrâneas em Juazeiro do Norte – CE (Brasil)

Abstract

The municipality of Juazeiro do Norte has as its source the underground spring, being considered the only source of public and private supply of the area. However, overexploitation is already proven in the intermittency of the old perennial drainage network, now perpetuated by releases of domestic sewage. The objective of this work was to apply the multivariate analysis to groundwater quality parameters in Juazeiro do Norte, Ceará, through the technique of factorial analysis, associated with multivariate cluster analysis. For evaluation purposes, 13 parameters from 11 tubular wells were studied: electrical conductivity, pH, dissolved oxygen, turbidity, color, nitrate, ammonia, alkalinity, total hardness, chloride, sulfate, total iron and total dissolved solids, measured in two moments, dry period (November/2002) and rainy season (April/2003). The results of the factorial analysis presented two factors, both for the dry period and for the rainy season, with eigenvalues greater than one, indicating the total of the variance caused by each factor. Multivariate cluster analysis, applied to the parameters of the first factor in both periods, presented dendrograms with formation of three groups. While the parameters of the second factor presented 3 and 2 groups for the dry and rainy periods, respectively.