Extreme water levels of the Vistula River and Gdansk Harbour

Using Canonical Correlation Analysis (CCA), Rozynski et al. (2006) have demonstrated that there is a weak correlation between the water levels of Vistula River and Gdansk Harbour. Herein the CCA analysis serves as a first step for a univariate bootstrap resampling technique, applied to investigate coincident extreme water levels of Vistula River and Gdansk Harbour. The CCA-derived assumption of statistical independence is argued as being a suitable working approximation for (outline) engineering design. This allows the goodness-of-fit of different statistical models to be assessed in a quantitative manner with a bootstrap method. This also provides a convenient means of defining extreme levels together with their confidence intervals. The analysis with two statistical methods provides insight into the character of joint coastal extremes in an estuary of a large north European river. The rationale and methodology are at least partly applicable to similar estuaries of northern Europe.