4. Evaluation methods
Many evaluation methods for urban water bodies and green spaces are
available, including AHP, principal component analysis (PCA), fuzzy
comprehensive evaluation method (FCED), cluster analysis (CA), etc. Each
method has its own advantages and disadvantages and is suitable for
different evaluation objectives. According to the complexity of
evaluation calculation and evaluation objects, evaluation methods can be
divided into general evaluation methods and comprehensive evaluation
methods. General evaluation methods include AHP and PCA. Comprehensive
evaluation methods are obtained introducing the membership degree of
fuzzy mathematics and the grayscale concept of gray system theory and
include FCED and CA.