A long-term trend, fluctuations and probability of the sea level at the southern Baltic coast

Wigniewski B. and Wolski T., 2011. A long-term trend, fluctuations and probability of the sea level at the southern Baltic coast Journal of Coastal Research, SI 64 (Proceedings of the 11th International Coastal Symposium), 255-259. Szczecin, Poland, ISSN 0749-0208 It is of utmost importance to monitor sea level fluctuations so that processes and effects in the coastal zone are understood, their adverse consequences are adequately forecast, and appropriate preventive measures be taken, if possible The aim of the study was the analysis of the series of data on sea levels on the Polish coast. The least squares method is used to identify trends in multi-annual variability of the sea level. Fourier spectral analysis one used for the determine of cycles of water levels oscillations. In analyses of the probability of maximum sea levels one used Gumbel and Pearson III the type distribution The Polish Baltic coast shows a variability in the rate of mean sea level changes. In the recent 60 years of continuous observations (1947-2006), the differences between the rates determined for different parts of the coast ranged from 1.0 (western part) to 2.5 mm/yr (eastern part). The variability in the rate of sea level changes at the Polish coast is evidenced also by the spectral analysis revealing considerable fluctuations and cyclicities: a distinct 3-yr cycle and somewhat weaker cycles of 4.6, 6.7, and 8.6 years. The obtained results theoretical sea levels and their probabilities of occurrence can be considered reliable because of the long observation series of sea levels.