144
A. Krawiec and A. Sadurski
From the centrally located Silesian Upland in the Carpathian Foreland, a range of
highlands stretches through the ´
Swi˛ etokrzyskie Mountains towards the east. The area
is predominantly corrugated and hilly, and several rivers which later become tributaries of the Vistula and the Oder, have their sources in the highland area. Through
the central part of the country, from Belarus in the east to Germany in the west,
stretches a gently rolling flat landscape of the elevation levels between 50 and 200 m
amsl. Classified as part of the Polish Lowlands or Polish and German Lowlands.
In the north, the Baltic Coast is separated from the rest of the country by a belt of
Lakelands characterised by diverse landscapes of the young glacial type.
The central and northern parts of the country are covered by the sediments of the
youngest ice age – the Vistulian Glaciation. The contemporary hydrographic network
as well as the Baltic Sea result from the morphogenesis of the Vistulian Glaciation
in the period of the past 45,000–12,000 years. The inland area of the Baltic Seais a
relatively young reservoir in the geological sense of the word. Its history does not
exceed 12,000 years. It is a brackish (saline) water reservoir. As it is intensively
recharged by rivers, the overall average tributary of which reaches 14,500 m
3 /s, it
would become a freshwater lake within 50 years if the inflows of saline water from
the North Sea through the Danish straits were cut off.
8.2.1 Outline of Hydrogeological Conditions in Poland
In the range of highlands, foothills and mountains, groundwater occurs mainly in
fractured aquifers as well as in pore and fractured aquifers and karstic and fractured aquifers. The systems of cracks, tectonic dislocations, and discontinuities
form complicated and heterogeneous aquifers. The deepest aquifers, which have
the broadest range and carry substantial amounts of groundwater, are connected with
dislocation zones and faults. Only in river valleys, groundwaters are connected with
sandy and gravelly alluvial deposits. In the greatest morphological depressions – in
drainage areas – groundwaters are carried beyond the range of elevations and mountains. They simultaneously function as buffers between surface waters in the beds of
streams, creeks and rivers, and rock aquifers. In the periods of high water levels and
high precipitation, the groundwater table rises by a few metres, whereas during the
droughts water stored in alluvial soil are drained by flows. The main groundwater
reservoirs – MGR [2], in the foothill and mountain zones are connected mainly with
the valleys of major rivers or buried valleys of former rivers. The thickness of alluvial
soils in these reservoirs reaches even 100 m and are characterised by high hydraulic
conductivity (transmissivity).
The zone of Mid-Polish uplands, which also includes the Holy Cross Mountains is
characterised by a low thickness of the Quaternary layers of the glacial, fluvioglacial,
fluvial and lake origin. Inland abatements, they frequently form the first aquifer level
below ground. At greater depths, there occur fractured aquifers as well as pore and
fractured aquifers in the Mesozoic layers, particularly in the Cretaceous and Jurassic
aquifer levels. In the areas of the highest ground ordinates, the Mesozoic strata
A. Krawiec and A. Sadurski
From the centrally located Silesian Upland in the Carpathian Foreland, a range of
highlands stretches through the ´
Swi˛ etokrzyskie Mountains towards the east. The area
is predominantly corrugated and hilly, and several rivers which later become tributaries of the Vistula and the Oder, have their sources in the highland area. Through
the central part of the country, from Belarus in the east to Germany in the west,
stretches a gently rolling flat landscape of the elevation levels between 50 and 200 m
amsl. Classified as part of the Polish Lowlands or Polish and German Lowlands.
In the north, the Baltic Coast is separated from the rest of the country by a belt of
Lakelands characterised by diverse landscapes of the young glacial type.
The central and northern parts of the country are covered by the sediments of the
youngest ice age – the Vistulian Glaciation. The contemporary hydrographic network
as well as the Baltic Sea result from the morphogenesis of the Vistulian Glaciation
in the period of the past 45,000–12,000 years. The inland area of the Baltic Seais a
relatively young reservoir in the geological sense of the word. Its history does not
exceed 12,000 years. It is a brackish (saline) water reservoir. As it is intensively
recharged by rivers, the overall average tributary of which reaches 14,500 m
3 /s, it
would become a freshwater lake within 50 years if the inflows of saline water from
the North Sea through the Danish straits were cut off.
8.2.1 Outline of Hydrogeological Conditions in Poland
In the range of highlands, foothills and mountains, groundwater occurs mainly in
fractured aquifers as well as in pore and fractured aquifers and karstic and fractured aquifers. The systems of cracks, tectonic dislocations, and discontinuities
form complicated and heterogeneous aquifers. The deepest aquifers, which have
the broadest range and carry substantial amounts of groundwater, are connected with
dislocation zones and faults. Only in river valleys, groundwaters are connected with
sandy and gravelly alluvial deposits. In the greatest morphological depressions – in
drainage areas – groundwaters are carried beyond the range of elevations and mountains. They simultaneously function as buffers between surface waters in the beds of
streams, creeks and rivers, and rock aquifers. In the periods of high water levels and
high precipitation, the groundwater table rises by a few metres, whereas during the
droughts water stored in alluvial soil are drained by flows. The main groundwater
reservoirs – MGR [2], in the foothill and mountain zones are connected mainly with
the valleys of major rivers or buried valleys of former rivers. The thickness of alluvial
soils in these reservoirs reaches even 100 m and are characterised by high hydraulic
conductivity (transmissivity).
The zone of Mid-Polish uplands, which also includes the Holy Cross Mountains is
characterised by a low thickness of the Quaternary layers of the glacial, fluvioglacial,
fluvial and lake origin. Inland abatements, they frequently form the first aquifer level
below ground. At greater depths, there occur fractured aquifers as well as pore and
fractured aquifers in the Mesozoic layers, particularly in the Cretaceous and Jurassic
aquifer levels. In the areas of the highest ground ordinates, the Mesozoic strata