Fuzzy Comprehensive Evaluation of River Health Using (1/2, 2) EM Method

In this paper, river health evaluation is decomposed into a hierarchical structure. Weights for each index of each grade are determined with the (1/2,2) EM method. The relative membership degree of different evaluation grade standards is then calculated with a fuzzy comprehensive evaluation based on fuzzy theory. The results present a comprehensive evaluation of river health and a scientific basis for river health management.