Spatial and temporal mapping of groundwater salinity using ordinary kriging and indicator kriging: The case of Bafra Plain, Turkey

Groundwater salinity contributes significantly to soil salinization in irrigated areas. In this study, spatial and temporal analyses of groundwater salinity were performed based on data from 97 wells monitored over a 7-year period. ArcGIS Geostatistical Analyst was used in exploratory data analysis, semivariogram model selection, cross-validation and development of a groundwater salinity distribution pattern. Groundwater salinity semivariogram models varied by year and included exponential (2004, 2009), spherical (2005), J-Bessel (2006) and rational (2007, 2008, 2010) models. Ordinary Kriging (OK) was used to analyze spatial variability of groundwater salinity, whereas Indicator Kriging (IK) was used to analyze groundwater salinity in relation to pollution threshold values.