Variable evaluation model and its application on the assessment of river ecosystem health

The evaluation of river ecosystem health is significant for the sustainable development of cities. In practical application, evaluation criteria are shown in interval pattern. However, in some commonly used methods, evaluation criteria of discrete values are often taken. Furthermore, the simplification of index from interval pattern to the point value form affects the rationality and accuracy of evaluation. The fuzzy variable model can solve this problem by combining with multiple attribute intervals. Based on this method, the ecosystem health of a river was assessed. Results show that the model is applicable in the assessment of river ecosystem health with more reliability.