Qualitative Multicriteria Methods for Fuzzy Evaluation Problems An lllustration of economic-ecological evaluation

It is nowadays increasingly realized that environmental and resource problems generally have complicated economie and ecological dimensions. Therefore, there is a clear need for models offering a comprehensible and operational representation of a real-world environmental system. A great variety of quantitative (descriptive and forecasting) models models nas been developed for compound environmental systems, but there is still a need in a planning context for evaluation methods taking into account information of a "mixed" (qualitative and quantitative) type. This paper presents a new discrete multicriteria decision aid (MCDA) model whose impact (or evaluation) matrix may include either crisp, stochastic or fuzzy measurements of the performance of an alternative an with respect to a criterion gm. No traditional weighting of criteria is used in this method. From an empirical point of view, this model is particularly suitable for economic-ecological modelling incorporating various degrees of precision of the variables measured. From a methodological point of view, two main issues will be faced here: the problem of equivalence of the used procedures in order to standardize the various evaluations (of a mixed type) of the performance of alternatives according to different criteria; the problem of comparison of fuzzy numbers typical of all fuzzy multicriteria methods. An illustrative numerical example will be presented at the end of the paper.