Assessment of seawater intrusion in a coastal aquifer by using correlation, principal component, and factor analyses

Hydrogeochemical characterization of the Erzin Plain coastal aquifer has been accomplished in this research to investigate the spatial and transient behavior of its water quality. The aquifer is located along the Mediterranean coast and forms one of the most productive aquifers in Turkey. Chemical analyses of groundwater samples collected from the aquifer during 1964-1968 (128 samples), May 1993 (30 samples), October 1993 (37 samples), and June 1994 (20 samples) constitute the available groundwater quality data set. The characteristics of the groundwater samples were evaluated statistically by correlation, principal component, and factor analyses to investigate interrelations among various groundwater quality and aquifer property parameters and to assess the occurrence of seawater intrusion. Application of principal component and factor analyses yielded two groups of variables indicative of seawater and freshwater. The basin is being contaminated by seawater, although it was not possible to locate the intrusion due to lack of sufficient data. The study emphasizes that management policies be reorganized for optimal use of the aquifer.