Analysis of Lake Water Levels Fluctuations in Poland and Belarus

Abstract

On the basis of the mean volume of annual water levels for 25 lakes (9 Belarusian and 16 Polish) in the period of 55 years (1956-2010) the spectral time analysis of water levels fluctuations has been executed. The spectral time analysis included two parts: analysis based on calculating the variance specters in comprised time distances and analysis of similarity in spectral images of water levels. The first part of the research has shown that for Belarus the most often observed cycles were 3, 5 and 10 years cycles. The majority of Polish lakes have cycles of 5 and 10 years. The second part of the research allowed dividing lakes into three groups. The first group included 14 lakes distinguished by smooth curves with no significant peaks and is represented by the lakes of the central and northern part of Belarus and eastern part of Poland. The second group shows four-year variability and includes lakes of the eastern part of Belarus. The third group is distinguished by a peak of three-year water fluctuation and includes lakes of central and north Poland.