Statistical modeling of groundwater geochemistry in northeastern Brazil

Abstract The objective is to characterize the hydrochemical and qualitative composition of the groundwater of the Beberibe aquifer located in the Northeast of Brazil (NEB) using geostatistical, geoprocessing, and multivariate analysis techniques. The Beberibe aquifer is located in the state of Pernambuco (PE), NEB, and is responsible for supplying water to the northern portion of the Recife Metropolitan Region (RMRE). The data collected came from 34 georeferenced mining and mineral water production units. From this, a Piper diagram was constructed and hydrogeological and hydrochemical spatial maps were generated. The data were submitted to descriptive statistics, geostatistics, and principal component analysis (PCA). The results showed that the artesian wells near the coast have a porous geological formation. In all artesian wells, the waters are of the mixed bicarbonate type and highly potable for human consumption. The coefficient of variation was medium to high for all hydrochemical variables. The variables showed a better fit to the Gaussian model, in the study of spatial dependence. In PCA, Cl was the one with the highest correlation with nitrate (NO3). The anthropogenic influence on water quality at the center of RMRE, mainly on NO3 concentrations, had a direct impact on water quality for human health.