Fuzzy evaluation of water quality classification

Traditional classification methods of the water quality parameters use crisp set, and the concentrations values which are close or far from the limits are considered in same classes. Moreover, usually, several parameters are considered in quality determination; therefore, differences of the classes of the parameters may be vagueness, especially, in public consideration. In this study, an index model for quality evaluation of surface water quality classification using fuzzy logic is proposed. In the method, traditional quality classes are transformed into continuous form and then the concentration values of the different quality parameters are summed using fuzzy rules, finally, defuzzyfication of this summed values develops the index. An application of this proposed index model for physical and inorganic chemical parameters in the Eber Lake water (in Turkey) are studied to demonstrate the practical application and feasibility of this index. (C) 2006 Elsevier Ltd. All rights reserved.