Chapter 9
Flow Regime Patterns and Their Changes
Dariusz Wrzesi ´
nski
Abstract Poland is characterized by relatively significantly diversified environmental conditions, reflected in various water supply conditions and seasonality of
the river flow, which determines the flow regime. Based on the Pardé coefficient, five
types of river regime: three nival (snowy) – poorly, moderately and well-formed,
nival-pluvial (snowy-rainy) and pluvial-nival (rainy-snowy), respectively, can be
distinguished. While the nival regime is represented mainly by lowland rivers in the
central and northern parts of the country, rivers in the southern, upland and mountainous parts have the nival-pluvial and pluvial-nival regimes. Rivers representing
the nival poorly formed type are characterized by the most even flows and the highest
share of the groundwater flow in the total flow in the annual cycle. In contrast, rivers
with the nival well-formed regime are distinguished by the most contrasting types
of periods, from deep low-water to very high high-water. Climate changes and the
human impact on water relations make the features of the river flow regime change.
Rivers with similar changes in flow conditions, except from those with transformation of water relations caused by human activity, also represent similar geographical
regions. This indicates the importance of climatic conditions in the modification of
the characteristics of the flow regime. Certain evidence of the influence of climatic
conditions on changes in the flow regime in the winter-spring period may be a significant decrease in winter flows observed in many rivers, and a delayed increase in the
spring thaw in the 1950s and 1960s. In turn, in the 1970s and 1980s in these rivers,
there was a disappearance of the winter low-water stages associated with a remarkable increase in the winter flow. These regularities indicate the noticeable impact of
changes in the intensity of the North Atlantic Oscillation on the transformation of the
characteristics of the flow regime of rivers in Poland. Research confirms that there is
a temporarily and spatially differentiated impact of the North Atlantic Oscillation on
the level of river flows. This impact is not strong but noticeable. It is observed with
varying intensity in rivers in many regions of the country, mainly in winter, spring
and summer.
D. Wrzesi´ nski (B)
Department of Hydrology and Water Management, Institute of Physical Geography and
Environmental Planning, Adam Mickiewicz University, Bogumiła Krygowskiego 10, 61-680
Pozna´ n, Poland
e-mail: darwrze@amu.edu.pl
© Springer Nature Switzerland AG 2021
M. Zeleˇ náková et al. (eds.), Management of Water Resources in Poland, Springer Water,
https://doi.org/10.1007/978-3-030-61965-7_9
163
Flow Regime Patterns and Their Changes
Dariusz Wrzesi ´
nski
Abstract Poland is characterized by relatively significantly diversified environmental conditions, reflected in various water supply conditions and seasonality of
the river flow, which determines the flow regime. Based on the Pardé coefficient, five
types of river regime: three nival (snowy) – poorly, moderately and well-formed,
nival-pluvial (snowy-rainy) and pluvial-nival (rainy-snowy), respectively, can be
distinguished. While the nival regime is represented mainly by lowland rivers in the
central and northern parts of the country, rivers in the southern, upland and mountainous parts have the nival-pluvial and pluvial-nival regimes. Rivers representing
the nival poorly formed type are characterized by the most even flows and the highest
share of the groundwater flow in the total flow in the annual cycle. In contrast, rivers
with the nival well-formed regime are distinguished by the most contrasting types
of periods, from deep low-water to very high high-water. Climate changes and the
human impact on water relations make the features of the river flow regime change.
Rivers with similar changes in flow conditions, except from those with transformation of water relations caused by human activity, also represent similar geographical
regions. This indicates the importance of climatic conditions in the modification of
the characteristics of the flow regime. Certain evidence of the influence of climatic
conditions on changes in the flow regime in the winter-spring period may be a significant decrease in winter flows observed in many rivers, and a delayed increase in the
spring thaw in the 1950s and 1960s. In turn, in the 1970s and 1980s in these rivers,
there was a disappearance of the winter low-water stages associated with a remarkable increase in the winter flow. These regularities indicate the noticeable impact of
changes in the intensity of the North Atlantic Oscillation on the transformation of the
characteristics of the flow regime of rivers in Poland. Research confirms that there is
a temporarily and spatially differentiated impact of the North Atlantic Oscillation on
the level of river flows. This impact is not strong but noticeable. It is observed with
varying intensity in rivers in many regions of the country, mainly in winter, spring
and summer.
D. Wrzesi´ nski (B)
Department of Hydrology and Water Management, Institute of Physical Geography and
Environmental Planning, Adam Mickiewicz University, Bogumiła Krygowskiego 10, 61-680
Pozna´ n, Poland
e-mail: darwrze@amu.edu.pl
© Springer Nature Switzerland AG 2021
M. Zeleˇ náková et al. (eds.), Management of Water Resources in Poland, Springer Water,
https://doi.org/10.1007/978-3-030-61965-7_9
163