Bayesian Water Quality Evaluation Model Based on Generalized Triangular Fuzzy Number and its Application

In view of the incompatibility of various indicators in water quality evaluation, as well as the uncertainty and fuzziness of water quality grade, this paper introduces the Bayesian theory and fuzzy number theory, and proposes a generalized triangular fuzzy number based comprehensive water quality evaluation model to evaluate the water quality in Wuhan section of Yangtze River. On this basis, a water quality evaluation system is established from the six dimensions of TP, NH4+-N, COD, DO, As and fecal coliform group. Then, the weight of water quality evaluation index is comprehensively determined by the variation coefficient method. Finally, the water quality category was determined according to the posterior probability corresponding to each class at the monitoring point. Through experiments, the evaluation results of the proposed model are compared with the single-parameter model, comprehensive evaluation method model, grey correlation analysis model and multivariate statistical analysis model. The results show that the water quality evaluation model based on the generalized triangle fuzzy number is more scientific and accurate, and the evaluation results are consistent with the actual water quality in the study area. Compared with the other four classical evaluation models, the proposed method has higher accuracy in water quality evaluation, and better application value in water quality evaluation system.