Application of geostatistical methods to groundwater salinization problems: A review

Groundwater salinization is considered to be one of the most severe and complex phenomena affecting coastal regions worldwide, occurring when high concentrations of water-soluble salts are present in groundwater sys-tems. Geostatistics is a branch of statistics used to analyze and predict the spatio-temporal variability of such complex phenomena. In particular, numerous geostatistical approaches and technologies are currently used to identify and map salinity-affected regions, investigate how salinity indicators influence groundwater mecha-nisms, and eventually design optimal groundwater management policies. This article reviews recent key appli-cations of geostatistical methods to address challenges relevant to groundwater salinization. The basic principles of geostatistics are briefly described, and numerous studies are discussed that employ geostatistical and multi-variate tools for identifying the origin of salinity sources, clarifying the relationship among salinity indicators and groundwater processes, and propagating the uncertainty of the inputs to the outputs of either physically -based or surrogate models of relevant geological systems. Finally, several recommendations and future di-rections are identified with regards to the most popular methods and with regards to key geostatistical methods whose application in this thematic area is still very limited.