10 Flow Seasonality in Two Big Polish Rivers – The Vistula …
193
R² = 0.9919
R² = 0.8822
140
150
160
170
180
190
200
160
165
170
175
180
185
190
195
200
TPO/PK(Oder)
TPO/PK(Vistula)
PK
[day]
TPO [day]
Fig. 10.2 TPO and PK relationships for the Vistula and the Oder gauges
from 12.4 to 9.5 and from 29.5 to 20.3, respectively. A similar decrease is observed
for the Vistula, i.e. from about 14 to 10.1 for GMO, and from 31.8 to 23.4 for IS
(Tables 10.2 and 10.3). However, due to changes in flow regime, these drops do not
follow a regular pattern as the area of the basins increases. Exemplary irregularities
include a local decrease in seasonality (IS and GMO) at Nowa Sól gauge for the Oder
and local increase in seasonality (IS and GMO) at Zawichost gauge for the Vistula.
These phenomena will be discussed in more detail later in this chapter.
The correlation between both seasonality parameters in the gauge data of both
rivers is slightly weaker than that described above for PK and TPO. However, if
all water gauges from both basins are pooled together, the relationship between
IS and GMO is clear and has a curvilinear character (Fig. 10.3). The form of the
equation shows that an increase in GMO is accompanied by a clear albeit diminishing
growth in IS. Therefore, the increase in the catchment area significantly reduces flow
seasonality.
Changes in all four parameters of flow seasonality depending on the length of the
Vistula and its basin area are illustrated in the diagrams in Fig. 10.4. The diagrams
clearly show some of the regularities indicated before. IS curve collapses along the
Vistula course correspond perfectly with regime changes and seasonal structure of
the flow caused by entering of two large, water-rich mountain rivers: the Dunajec
(Szczucin gauge) and the San (Zawichost gauge), as well as the impact of Włocławek
Reservoir. A different seasonal structure of the flow from the catchments of these
two rivers causes abrupt fluctuations in the Vistula flow seasonality in the middle
and lower sections. The Włocławek Reservoir affects the Vistula in a similar manner,
while the entrance of the Narew (K˛ epa Polska gauge) does not evoke this type of
193
R² = 0.9919
R² = 0.8822
140
150
160
170
180
190
200
160
165
170
175
180
185
190
195
200
TPO/PK(Oder)
TPO/PK(Vistula)
PK
[day]
TPO [day]
Fig. 10.2 TPO and PK relationships for the Vistula and the Oder gauges
from 12.4 to 9.5 and from 29.5 to 20.3, respectively. A similar decrease is observed
for the Vistula, i.e. from about 14 to 10.1 for GMO, and from 31.8 to 23.4 for IS
(Tables 10.2 and 10.3). However, due to changes in flow regime, these drops do not
follow a regular pattern as the area of the basins increases. Exemplary irregularities
include a local decrease in seasonality (IS and GMO) at Nowa Sól gauge for the Oder
and local increase in seasonality (IS and GMO) at Zawichost gauge for the Vistula.
These phenomena will be discussed in more detail later in this chapter.
The correlation between both seasonality parameters in the gauge data of both
rivers is slightly weaker than that described above for PK and TPO. However, if
all water gauges from both basins are pooled together, the relationship between
IS and GMO is clear and has a curvilinear character (Fig. 10.3). The form of the
equation shows that an increase in GMO is accompanied by a clear albeit diminishing
growth in IS. Therefore, the increase in the catchment area significantly reduces flow
seasonality.
Changes in all four parameters of flow seasonality depending on the length of the
Vistula and its basin area are illustrated in the diagrams in Fig. 10.4. The diagrams
clearly show some of the regularities indicated before. IS curve collapses along the
Vistula course correspond perfectly with regime changes and seasonal structure of
the flow caused by entering of two large, water-rich mountain rivers: the Dunajec
(Szczucin gauge) and the San (Zawichost gauge), as well as the impact of Włocławek
Reservoir. A different seasonal structure of the flow from the catchments of these
two rivers causes abrupt fluctuations in the Vistula flow seasonality in the middle
and lower sections. The Włocławek Reservoir affects the Vistula in a similar manner,
while the entrance of the Narew (K˛ epa Polska gauge) does not evoke this type of