ANALYSIS OF GROUNDWATER QUALITY ACCEPTABILITY FOR DRINKING PURPOSES IN NINE CITIES IN ISFAHAN PROVINCE USING FUZZY INFERENCE SYSTEM

Fuzzy evaluation presents a certainty level for the acceptability of water for drinking purposes based on prescribed standards of various organizations and perception of the experts. In this study, fuzzy set theory was applied for decision making on the suitability of certain groundwater resources for drinking purposes based on chemical quality. The quality of water was expressed in indefinite environment of monitored data and prescribed standards given in a non-probabilistic sense. From the 9 cities in Esfahan Province, 29 groundwater samples that were collected from the drinking water wells are used in this study. These samples were analyzed for 11 chemical parameters. But, finally 9 parameters were used for evaluation of drinking water quality. The results showed that 10 water samples were in the “desirable” category with a certainty level of 84-97%, 9 samples were in the “acceptable” category with a certainty level of 50-100%, and 10 samples were in the “non-acceptable” category with a certainty level of 50-95%. Furthermore, about 65% of the samples were in the “desirable” or “acceptable” categories for drinking purposes.