Notice of Retraction A Modified DRASTIC Model Based on Grey Method for Assessing Groundwater Vulnerability

A grey method has been used to compute weights of the criteria in DRASTIC model in this paper. As a popular method, however, DRASTIC cannot describe a continuous transition of contamination from the easiest to be polluted to the most difficult to be polluted, and weights of seven parameters in DRASTIC are weighted using expert opinions according to their importance in influencing groundwater vulnerability, that has the disadvantage of subjectivity. This paper introduces a gray method to improve method of determining the weights in DRASTIC, which is an objective method based on the correlation coefficient of objects to be compared to determine the relevance of each other. The improved model not only keeps the index continuity, but also maintains physics meaning. Research shows that modified model has a higher accuracy comparing with other ways.