Hilbert-Huang Transform Based Time Series Analysis of Water Quality Parameters

In order to study affecting the variation rule of the water quality parameters, we employed Hilbert-Huang Transform (HHT) to analyze the concentration value of Cd using 26 years' data in F3 site, and got the variation rule and trends of Cd. The results showed that: In Station F3, Cd concentration is non-stationary time series, and the trend is clearly for the upward trend, a slight decline in the future, the main cycle of 10 months, 43 months, 51 months and 73 months. To research the variation rule of Cd concentration and forecast the trends is meaningful.