200
P. Jokiel and P. Tomalski
Fig. 10.8 Multiannual changes in seasonality index (IS) for six selected water gauges of the Vistula
and the Oder. Explanations: a – water gauges ´
Scinawa (ISs) and Jagodniki (ISj); b – water gauges
Poł˛ ecko (ISp) and Warszawa (ISw); c – water gauges Gozdowice (ISg) and Tczew (ISt); ISsr
– average concentration date; R – correlation coefficient; R 2 – determination coefficient
fluctuation phases and year to year scale changes. A small difference was found for
the amplitudes of polynomial trend curves. The difference was considerably bigger
at ´
Scinawa gauge with a significant trend. The average multiannual flow seasonality
indices at both water gauges are comparable, similarly as the scale of long-term IS
variability.
Multiannual IS differed significantly at the gauges closing middle parts of both
basins (Fig. 10.8b). The Vistula flow showed slightly greater seasonality than that
of the Oder, while the dynamics of multiannual changes in the Oder was, similarly
as in the upper section, slightly greater than in the Vistula. This was confirmed by,