Using ARMA and GM (1, 1) Models to Predict the Water Quality of the Old Jhuoshuei River- A Comparative Study

• Main Authors: Wei-Pang Kang, 康維邦
• Other Authors: Tzu-Yi Pai
• Format: Others
• Language: zh-TW
• Published: 2012
• Online Access: http://ndltd.ncl.edu.tw/handle/60885944349954025217

碩士 === 朝陽科技大學 === 環境工程與管理系碩士班 === 100 === Abstract This study used ARMA and GM (1, 1) models to predict the concentrations of DO (Dissolved Oxygen), BOD (biochemical oxygen demand), COD (chemical oxygen), and ammonia (NH3-N) in the Old Jhuoshuei River and compare the results. the MAPE of using ARMA to predict the DO in the Old Jhuoshuei is between 37.04 and 98.50. The CR (correlation coefficient) is between -0.59 and 0.62; the MAPE of predicting the BOD is between 142.29 and 511.79; the R value of the prediction is between -0.57 and 0.19. The MAPE of predicting COD is between 106.72 and 300.09; the R value of prediction is between -0.51 and 0.13. The MAPE of predicting NH3-N is between 63.81 and 140.68; the R value of prediction is between -0.50 and -0.05. The MAPE of using GM(1, 1) model to predict the DO of the Old Jhuoshuei River is between 25.31 and 36.38; the R value of prediction is between 0.39 and 0.73. The MAPE of predicting BOD is between 49.28 and 82.00; the R value of prediction is between 0.28 and 0.51. The MAPE of predicting COD is between 48.74 and 117.38; the R value of prediction is between -0.11 and 0.46. The MAPE of predicting NH3-N is between 45.64 and 60.05; the R value of prediction is between 0.29 and 0.37. Regardless of predicting DO, BOD, COD or NH3-N, the three GM (1, 1) models of GM (1, 1, x (0)), GM (1, 1, a), GM (1, 1, b) are relatively better in performance.