摘要
Based on the observations of the air pollutants from 2001 to 2005 in the urban area of Chengdu City, the air pollution index is obtained and analyzed. The authors use the auto-regressive moving average (ARMA) method to simulate the actual API by time series analysis. They also carry out and discuss the performance evaluation of the adopted model according to root mean square error (RMSE). According to the analysis of the air pollution data and API, the result shows that the air pollution quality in the urban area of Chengdu is of a seasonal variation law with lower levels in summer and higher levels in other seasons. The results indicate that time series analysis method can provide reliable, satisfactory predictions for the interested problem and is expect to be an alternative tool for practical assessment and justification.