67-The Methodology of Long Range Forecasting of Levels of Large Lakes.

Abstract

The methodology of revealing of periodicities in time series of the lake level and water balance components is elaborated. It combines the development of the original physically based model of oscillations of mutually related lake characteristics and approximation of lake level and water balance components by sine functions using the method of least squares. The periodicities were revealed respectively for the level of the Caspian Sea and the Ladoga Lake. The respective sums of the periodicities show a high correlation with the considered time series and were applied for their long range forecast estimations. The validation of the forecast results by the new independent data shows that the forecasted and real values of the level of the Caspian Sea and the Ladoga Lake are in a good accordance.