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K. Kubiak-Wójcicka et al.
3. In total, there are 7081 lakes in Poland with an area of over 1 ha, and a total
capacity of 19.7349 km
3 . As much as 99.32% of the lakes’ capacity is concentrated in the area covered by the last glaciation (Masurian Lake District, Pomeranian Lake District and Wielkopolska-Kujawy Lake District). The retention of
the area north of the boundary line of the maximum range of the last glaciation
is 162 mm. This represents only 10% of the average annual rainfall, and the
value is about 3.5 times lower than the average runoff from Poland.
4. The lakes located in river valleys are small reservoirs that were created as a
result of both natural and anthropogenic processes that took place in the river
valleys. These reservoirs are an important and underestimated element of small
retention, however hardly explored. Lakes in river valleys are subject to dynamic
disappearance processes and require detailed bathymetric, hydrochemical and
hydrobiological studies.
5. Special attention should be paid to groundwater outflows based on field observations and review of available literature. The occurrence and efficiency of
springs is very important. As well springs’ use and needs for their protection in
Poland. Particular attention has to be paid to the role of springs in the natural
system and culture, as well as to their importance in local water management.
Necessary urgent protective and preventive actions were indicated in order to
preserve Polish springs as objects of great natural, landscape, economic and
cultural significance.
6. Groundwater is the main source of drinking water supply for people in Poland.
Over 70% the water demand is covered by that source. The main reason is
the abundance of this resource and its good quality. According to the water
management policy until 2030, these resources are protected and controlled
by a monitoring system. Generally, at a depth of 200–300 m on the Polish
Lowlands, there occur saline water of Cl-Na type. These waters are the subject
of the growing interest of newly constructed spas and geothermal plants.
7. Five types of hydrological regime are distinguished in Poland. Typological
differentiation of the flow regime largely depended on environmental conditions, especially climatic, but also physical-geographical characteristics of river
basins. Climate change, along with human impact, will lead to changes in
regime features, as evidenced by river responses to changes in the North Atlantic
Oscillation.
8. Two largest Polish rivers follow basically the same course from south to north as
they drain the surrounding regions. It is therefore clear that their flow seasonality
structure shows spatial differences. However, as the courses of both rivers are
similar, greater differences are observed along the rivers than between their
basins. The river flow shows long-term oscillations due to changes in the water
balance components.
9. The spatial, seasonal and long-term variability of low flows in Poland in the
years 1951–2015. The minimum flows in Poland in the years 1951–2015 are
characterized by low seasonality level which generally follows the degree of
precipitation continentalism and catchment resources capacity; the exception is
the transit rivers Vistula and Oder where the seasonality index is almost stable
K. Kubiak-Wójcicka et al.
3. In total, there are 7081 lakes in Poland with an area of over 1 ha, and a total
capacity of 19.7349 km
3 . As much as 99.32% of the lakes’ capacity is concentrated in the area covered by the last glaciation (Masurian Lake District, Pomeranian Lake District and Wielkopolska-Kujawy Lake District). The retention of
the area north of the boundary line of the maximum range of the last glaciation
is 162 mm. This represents only 10% of the average annual rainfall, and the
value is about 3.5 times lower than the average runoff from Poland.
4. The lakes located in river valleys are small reservoirs that were created as a
result of both natural and anthropogenic processes that took place in the river
valleys. These reservoirs are an important and underestimated element of small
retention, however hardly explored. Lakes in river valleys are subject to dynamic
disappearance processes and require detailed bathymetric, hydrochemical and
hydrobiological studies.
5. Special attention should be paid to groundwater outflows based on field observations and review of available literature. The occurrence and efficiency of
springs is very important. As well springs’ use and needs for their protection in
Poland. Particular attention has to be paid to the role of springs in the natural
system and culture, as well as to their importance in local water management.
Necessary urgent protective and preventive actions were indicated in order to
preserve Polish springs as objects of great natural, landscape, economic and
cultural significance.
6. Groundwater is the main source of drinking water supply for people in Poland.
Over 70% the water demand is covered by that source. The main reason is
the abundance of this resource and its good quality. According to the water
management policy until 2030, these resources are protected and controlled
by a monitoring system. Generally, at a depth of 200–300 m on the Polish
Lowlands, there occur saline water of Cl-Na type. These waters are the subject
of the growing interest of newly constructed spas and geothermal plants.
7. Five types of hydrological regime are distinguished in Poland. Typological
differentiation of the flow regime largely depended on environmental conditions, especially climatic, but also physical-geographical characteristics of river
basins. Climate change, along with human impact, will lead to changes in
regime features, as evidenced by river responses to changes in the North Atlantic
Oscillation.
8. Two largest Polish rivers follow basically the same course from south to north as
they drain the surrounding regions. It is therefore clear that their flow seasonality
structure shows spatial differences. However, as the courses of both rivers are
similar, greater differences are observed along the rivers than between their
basins. The river flow shows long-term oscillations due to changes in the water
balance components.
9. The spatial, seasonal and long-term variability of low flows in Poland in the
years 1951–2015. The minimum flows in Poland in the years 1951–2015 are
characterized by low seasonality level which generally follows the degree of
precipitation continentalism and catchment resources capacity; the exception is
the transit rivers Vistula and Oder where the seasonality index is almost stable