Application of the Cloud Model Synthesis Method in Ecological Evaluation of Waterways

Table 1

Summary of evaluation methods.

No	Method	Application examples or features
1	Traditional composite index method	Li, T. et al. [10] established a hierarchical evaluation system and used the combined weighting method to evaluate it comprehensively
2	Fuzzy synthesis	Wu, Y. et al. [11] have conducted research studies on spatiotemporal variations of a small catchment by using the fuzzy comprehensive method
3	Gray clustering method	Chang, W. et al. [12] conducted research studies of the river waterway grade division based on the gray system theory [12, 13]
4	Possibility distribution	Included in fuzzy mathematics, it could forecast how things change and are suitable for representation and measurement of a small amount of data [8, 9]
5	Hesitant fuzzy linguistic term set	The ambiguity of the elements is preserved; an ordered and consecutive subset of the linguistic term is set for a linguistic variable [4, 5]
6	Proportional hesitant fuzzy linguistic term set	Compared with HFLTS, it would consider the linguistic terms and corresponding proportional information simultaneously [4, 5]
7	Cloud model synthesis method	Combines the vagueness and randomness in qualitative concepts and transforms them into quantitative expressions [6]