Establishment of Air Quality Assessment Model with Weight Based on Extension Theory

Combining extension engineering method with cluster analysis, the classic and limited matter elements were constructed according to air quality standards and main air affecting factors. The logical domain was extended from (0, 1)to (-∞ ,+∞), meanwhile, the quantitative analysis in the classic matter-set which only judged by Yes or No was extended to qualitative analysis, which could show the administrative level relation between the air quality factors better. By computing the weight of feature using AHP, air quality assessment model based on extension theory with varying weight was established. Not only could the new model show the whole level of air quality, but identify the main air pollution facts which exert great impact. The application in FUXIN city showed that the results between extension theory model of air quality in the evaluation ,Shanghai air quality index method and Fuzzy Comprehensive Evaluation method were mainly corresponding to each other.