Water Environment Quality Assessment Based on Normal Cloud-fuzzy Variable Set Evaluation Model

Water environmental quality assessment is an important groundwork for river planning, governance, and management. A normal cloud-fuzzy variable evaluation model which incorporated the minimum relative entropy weights was proposed to evaluate the water quality of 13 monitoring points in the Qinhuai River in 2016. The evaluation results proved to be more reasonable and effective in comparison with the results of the single-factor index evaluation method, fuzzy comprehensive evaluation method and cloud model. The analysis of model-level eigenvalue (H) showed that most of the water quality of the Upper Qinhuai River and Qinhuai New River is better in flood season than in non-flood season, which also showed the pollution characteristics of urban industry and domestic sewage. However, the water quality of the Outer Qinhuai River and inner Qinhuai River is worse in the flood season than in non-flood season, which showed the typical pollution characteristics of urban sewage and catering. The study results can be helpful for future evaluation and research of water environment in regions and river basins.