4.2. Comprehensive evaluation method
In FCED, some uncertain problems are determined according to the basic theory of fuzzy mathematics and the principle of fuzzy relationship. The evaluation results are more accurate, but the difficulty in weight determination and the ambiguous statistical interrelationships between indices also affect the evaluation process.
In CA, according to the principle of “type-clustering”, similar data are acquired for the purpose of analyzing the inherent characteristics and laws of things. The analysis process of CA is simple and intuitive, but it requires a sample size, which increases the difficulty in obtaining the clustering conclusion.
Through the improvement in basic evaluation methods, many comprehensive evaluation methods are gradually obtained. These evaluation methods can avoid excessive subjective influences and improve the accuracy of results. The analysis process is relatively simple and applicable to many problems. In the evaluation process of blue-green spaces, it is necessary to comprehensively consider its ecological background status, local social and economic conditions, residents’ experiences and feelings. Index selection and weight determination should be based on expert consultation and AHP, so the subjective factors affect the accuracy of evaluation results. Without comparison results, the rationality of evaluation results cannot be verified. Therefore, the AHP can be combined with the fuzzy evaluation method or the CA in order to improve evaluation results. In the future, according to the structures and functions of evaluation objects, based on the existing evaluation methods, combined evaluation methods can be used. In addition, more practical and convenient evaluation methods can be developed.