178
D. Wrzesi´ nski
9.4 Conclusions
Due to different environmental conditions, rivers in Poland are characterized by a
relatively large diversity of water supply conditions and seasonality of the river flow,
enhanced by its variability. This results in the distinction of five types of flow regime.
The lowland areas are dominated by three simple nival regimes: poorly, moderately
and well-formed, while in the highlands and in the mountain areas two complex
regimes, namely nival-pluvial and pluvial-nival can be distinguished. Determination
of the features of the river flow regime based on different approaches: supervised
and unsupervised, allowed a better recognition of the regularity of the river flow
variability in the annual cycle. Key elements determining water resources, such as
duration, time of appearance and stability of the high and low water periods were
included. The paper also describes how contemporary changes in climatic conditions
and human impact on water conditions affect the characteristics of the river flow
regime. Multiannual and seasonal flow changes were found, which are of particular importance in the spring and summer seasons due to the adopted criteria of the
typology of the river regime. Studies confirmed that the destabilization of the flow
regime characteristics of many rivers in Poland may be triggered by the changing
climatic conditions. These are caused by the varied intensity of macro-scale air circulation types, such as the North Atlantic Oscillation, whose impact is not strong but
noticeable and statistically significant in the winter season. Recent research revealed
that the climatic conditions and flow regime of rivers in Poland may also be influenced
by the North Atlantic Thermohaline Circulation (NA THC) [30].
9.5 Recommendations
The obtained results of this study indicate that further research is needed to detect
changes in the water cycle, the amount of the river flow, and its regime at various
spatial scales in order to identify the hydrological consequences of contemporary
climate change and human impact.
Acknowledgements The author is grateful to the Institute of Meteorology and Water Management
in Warsaw for providing the data used in this paper.
References
1. Wo´ s A (2010) Climate of Poland in the second half of the 20th century. Wyd. Naukowe UAM,
Pozna´ n, 489 p (In Polish)
2. Gutry-Korycka M (2001) Geographical conditions of river regimes. WGSR UW, Warszawa,
192 p (In Polish)
3. D˛ ebski K (1961) Hydrological characteristics of Poland. PWN, Łód´ z-Warszawa (in Polish)
D. Wrzesi´ nski
9.4 Conclusions
Due to different environmental conditions, rivers in Poland are characterized by a
relatively large diversity of water supply conditions and seasonality of the river flow,
enhanced by its variability. This results in the distinction of five types of flow regime.
The lowland areas are dominated by three simple nival regimes: poorly, moderately
and well-formed, while in the highlands and in the mountain areas two complex
regimes, namely nival-pluvial and pluvial-nival can be distinguished. Determination
of the features of the river flow regime based on different approaches: supervised
and unsupervised, allowed a better recognition of the regularity of the river flow
variability in the annual cycle. Key elements determining water resources, such as
duration, time of appearance and stability of the high and low water periods were
included. The paper also describes how contemporary changes in climatic conditions
and human impact on water conditions affect the characteristics of the river flow
regime. Multiannual and seasonal flow changes were found, which are of particular importance in the spring and summer seasons due to the adopted criteria of the
typology of the river regime. Studies confirmed that the destabilization of the flow
regime characteristics of many rivers in Poland may be triggered by the changing
climatic conditions. These are caused by the varied intensity of macro-scale air circulation types, such as the North Atlantic Oscillation, whose impact is not strong but
noticeable and statistically significant in the winter season. Recent research revealed
that the climatic conditions and flow regime of rivers in Poland may also be influenced
by the North Atlantic Thermohaline Circulation (NA THC) [30].
9.5 Recommendations
The obtained results of this study indicate that further research is needed to detect
changes in the water cycle, the amount of the river flow, and its regime at various
spatial scales in order to identify the hydrological consequences of contemporary
climate change and human impact.
Acknowledgements The author is grateful to the Institute of Meteorology and Water Management
in Warsaw for providing the data used in this paper.
References
1. Wo´ s A (2010) Climate of Poland in the second half of the 20th century. Wyd. Naukowe UAM,
Pozna´ n, 489 p (In Polish)
2. Gutry-Korycka M (2001) Geographical conditions of river regimes. WGSR UW, Warszawa,
192 p (In Polish)
3. D˛ ebski K (1961) Hydrological characteristics of Poland. PWN, Łód´ z-Warszawa (in Polish)