Application of grey relational analysis and hierarchical cluster analysis in regional environmental noise pollution

The main sources of noise, correlations between four representative indicators and urban regional environmental noise pollution were applied by grey relational analysis and hierarchical cluster analysis in Wenzhou from 1997 to 2006. Results indicates that main noise sources of the city of Wenzhou were social life noise and industrial production noise, and hierarchical cluster analysis grouped the 10 years into three periods (2006, 1997-2000 and 2001-2005) corresponding to a relatively low pollution, very high pollution and moderate pollution years, respectively. Regional environmental noise pollution is a tendency to going down in recent years in Wenzhou. A combination of grey relational analysis and hierarchical cluster analysis provides a fast, easy and reliable method to explore temporal trends and the hidden structure.