Frequency Analysis and Predict of Sea Level Changes in the South Caspian Sea Using by Altimetry Field Data

In this study sea level chnges in Anzali station for 10 years, Neka station for 9 years and Noshahr station for 6 years was investigated and predicted. After studying the validity, altimetry field data were averaged monthly. For analyzing these measurements Fourier analysis, time series and frequency analysis were used.Fourier Coefficients amounts and monthly average harmonics of southern Caspian Sea level in each station were calculated and compared to each other, which result negligible difference between them. In this research FFT (Fast Fourier Transformation) method was used which exists in MATLAB software. Frequency range about 0.08 with its harmonics has main role.Anticipating result of statistical models ARMA has more adopts with frequency behavior of sea level in Anzali, Neka and Noshahr stations.Byhence, ARMA was the best model for time series elegancy of these series. Anticipating sea level diagrams in these 3 stations are showing that sea level in these stations are increasing. As water level after 12 months later in Anzali, Neka and Noshahr stations respectively predicted to be -25.91m, -25.81m and -25.79m.