Groundwater availability depends on its accessibility, as well as on its quality. A principal component analysis (PCA)
has been used to link the occurrence of natural (fluoride) and human (nitrate) pollutants with the hydrological
dynamics in the Selva Basin (NE Spain) as a means to analyze quality problems and provide strategies for water
resources exploitation. Statistical results show that both pollutants are independent, and they are related to
groundwater fluxes of different spatial scales. Fluoride is linked to regional groundwater systems, while nitrate is
related to local recharge produced within the basin. PCA thus permits relating a potential occurrence of pollutants to
specific characteristics of the hydrogeological system. It also becomes an approach to assess its vulnerability by
identifying key parameters related to pollution. Such a statistical outcome is of interest for water resources planning
with the aim to avoid locating production wells in areas that show hydrogeological or hydrochemical features
associated with either type of pollution.