Grey Clustering Evaluation on Regional Eco-environmental Quality Based on Normalized Index Value

[Objective]The aim was to assess regional eco-environmental quality by means of grey clustering method based on normalized index value.[Method]Eco-environmental quality in Chaohu basin was assessed by using grey clustering method based on normalized index value,and the evaluation results were compared with those of unascertained measure method to verify the feasibility of grey clustering method used to evaluate regional eco-environmental quality.[Result]In the grey clustering assessment based on normalized index value,indexes whose standard normalized values in the same grade were close to each other were classified into one class and had the same whitening function,which reduced the number of whitening functions.Grey clustering method based on normalized index value was used to assess eco-environmental quality in Chaohu basin,and the evaluation results were basically in accordance with those of unascertained measure method,namely eco-environmental quality in Hefei,Chaohu and Lu'an belonged to the third(pass),fourth(worse),fifth grade(bad),except for one grade difference in overall basin,and the results showed that the method had practicality and could be applied to assess regional eco-environmental quality.[Conclusion]The study could provide theoretical foundation for the establishment of comprehensive management countermeasures of regional ecological environment.