Understanding Groundwater Chemistry Using Statistics Techniques

In numerous coastal aquifers, particularly in semi-arid and arid regions, the salinization of groundwaters is of strategic water resource importance, since it places limitations of the use of the water for urban water supply and agricultural use. The hydrochemical differentiation of the salinization processes is very complex as there is considerable hydrochemical variability due to superposition of different processes: marine intrusion, recycling of wastewaters, continental saltwater contribution and pollution phenomena by agricultural activities. In this book, we try to describe the hydrological processes in the Korba coastal plain (NE of Tunisia) using hydrochemical data, correlation matrices and factor analysis to provide evidence of salinization processes. The application of Multivariate Statistics Techniques based on Principal component Analysis and Hierarchical Cluster Analysis has lead to the corroboration of the hypotheses developed from the hydrochemical study. Two factors were found that explained major hydrochemical processes in the aquifer. These factors reveal the existence of an intensive intrusion of seawater and mechanisms of nitrate contamination of groundwater.