An integrated approach for the assessment of groundwater contamination risk/vulnerability using analytical and numerical tools within a GIS frameworkAn integrated approach for the assessment of groundwater contamination risk/vulnerability using analytical and numerical tools within a GIS framework Peer-Reviewed Journal Publication Δημοσίευση σε Περιοδικό με Κριτές 2015-10-202015enThis paper presents a new integrated GIS modeling methodology for assessing groundwater contamination risk. Analytical and numerical tools within a GIS framework were used to define the raster maps of various factors interfering along the contaminant pathway from source to groundwater. In the proposed methodology, these factors were introduced into a unified GIS model for groundwater risk assessment that incorporates all the necessary information to improve the accuracy in the results. Fifteen factors were considered in order to estimate the spatial distribution of the groundwater contamination risk areas. Some of these factors such as artificial drainage and seepage velocity had not been used previously in GIS groundwater risk mapping. The study area, the island of Crete in Greece, was divided into five regions characterized by different degrees of groundwater risk ranging from very low to very high. A sensitivity analysis was performed and the developed methodology was validated for different contaminants that were detected in groundwater for the island of CreteΔημοσίευση σε επιστημονικό περιοδικό http://creativecommons.org/licenses/by/4.0/Hydrological Sciences Journal160111-132 Kourgialas Nektarios Κουργιαλας Νεκταριος Karatzas Giorgos Καρατζας Γιωργος Taylor & Francis agricultural contamination Complex aquifer systems decision support system environmental risk hazard vulnerability