ABSTRACT
Environmental regulations require the monitoring of the environmental state of a water basin in order to preserve and improve the water quality with respect to a target fixed in advance in terms of indexes. The necessity to represent a large amount of data related to an observation period and to compare it with respect to an ideal target (represented by a suitable index) compels to consider the uncertainty involved in the data survey and classification. The uncertainty arises from:
• lack of precision in environmental surveying, • vagueness of the quality index definitions, • arbitrariness in the classification with respect to the indices.
