48
Z. Michalczyk and J. Sposób
4.3 Water Resources of Poland
Water resources of an area depend on features of the geographic environment, and
particularly the geological structure, land relief, soils, land use, atmospheric precipitation, and evapotranspiration, and from the retention capacity of the ground. The
territory of Poland is a lowland area – areas with a height from 0 to 300 m amsl occupy
91.3% of the territory. Upland areas, elevated from 300 to 500 m amsl, occupy 5.6%,
and mountain areas – the remaining 3.1% of the area of Poland. The highest point
in the country is Rysy (2499 m amsl) in the Tatra Mountains, and the lowest the
depression in ˙
Zuławy (−1.8 m amsl). Despite the small elevation of the territory of
Poland above sea level (173 m amsl), the land relief of Poland shows considerable
variability, with a belt arrangement of geomorphological regions. The system of the
main features of land relief, arranged in latitudinal zones, results from the geological
structure. The Sudetes and Carpathians occupy the southern part of the country. The
Sudeten mountain ranges with a character of tectonic horsts, developed during the
Hercynian orogeny, are built of metamorphic stones. The Carpathians, developed in
the Alpine folding, are built of flysch formations (sandstones, slates, conglomerate
rocks) with low permeability. The highest part of the Carpathian range are the Tatra
Mountains, built in the eastern part of massive granitoids, and in the western part of
Mesozoic carbonate formations with high water drainage. A belt of uplands is located
to the north, mainly built of Mesozoic carbonate deposits: limestones, dolomites, and
margles. The ´
Swi˛ etokrzyskie Mountains are also built of Palaeozoic carbonate rocks
as well as sandstones and quartzites. The area of uplands is connected with a belt
of extensive lowlands with diverse morphology, shaped by the Pleistocene ice sheet.
Post-glacial formations occur on the surface, particularly moraine clays and sandy
formations constituting reservoirs of groundwaters with moderate and locally high
water capacity.
The land use structure of the territory of Poland is dominated by arable land
and forests (Table 4.1). They are areas with good conditions for precipitation water
retention, i.e. areas where groundwater resources develop, feeding rivers, springs, and
water intakes. Areas with low permeability and built-up areas occupy approximately
a dozen percent of the area. The surface area of rivers, ponds, ditches – land under
waters slightly exceeds 2.0% of the area of Poland.
The factor directly affecting water resources are climatic conditions, particularly
precipitation and air temperature, determining the amount of evapotranspiration.
Despite a relatively small area, the basic parameters describing climate features
show high spatial and seasonal variability. In the territory of Poland, mean precipitation in the years 1901–2000 equalled 628 mm, and outflow 175.2 mm, providing the
outflow coefficient of 0.278 [7]. In a year with an average humidity, the amount of
precipitation in the territory of the country varied from approximately 500 mm in the
lowland belt to more than 1000 mm in the mountains. The highest monthly precipitation and evapotranspiration totals in Poland occur in July. The lowest precipitation
and evapotranspiration occur in January and February.
Z. Michalczyk and J. Sposób
4.3 Water Resources of Poland
Water resources of an area depend on features of the geographic environment, and
particularly the geological structure, land relief, soils, land use, atmospheric precipitation, and evapotranspiration, and from the retention capacity of the ground. The
territory of Poland is a lowland area – areas with a height from 0 to 300 m amsl occupy
91.3% of the territory. Upland areas, elevated from 300 to 500 m amsl, occupy 5.6%,
and mountain areas – the remaining 3.1% of the area of Poland. The highest point
in the country is Rysy (2499 m amsl) in the Tatra Mountains, and the lowest the
depression in ˙
Zuławy (−1.8 m amsl). Despite the small elevation of the territory of
Poland above sea level (173 m amsl), the land relief of Poland shows considerable
variability, with a belt arrangement of geomorphological regions. The system of the
main features of land relief, arranged in latitudinal zones, results from the geological
structure. The Sudetes and Carpathians occupy the southern part of the country. The
Sudeten mountain ranges with a character of tectonic horsts, developed during the
Hercynian orogeny, are built of metamorphic stones. The Carpathians, developed in
the Alpine folding, are built of flysch formations (sandstones, slates, conglomerate
rocks) with low permeability. The highest part of the Carpathian range are the Tatra
Mountains, built in the eastern part of massive granitoids, and in the western part of
Mesozoic carbonate formations with high water drainage. A belt of uplands is located
to the north, mainly built of Mesozoic carbonate deposits: limestones, dolomites, and
margles. The ´
Swi˛ etokrzyskie Mountains are also built of Palaeozoic carbonate rocks
as well as sandstones and quartzites. The area of uplands is connected with a belt
of extensive lowlands with diverse morphology, shaped by the Pleistocene ice sheet.
Post-glacial formations occur on the surface, particularly moraine clays and sandy
formations constituting reservoirs of groundwaters with moderate and locally high
water capacity.
The land use structure of the territory of Poland is dominated by arable land
and forests (Table 4.1). They are areas with good conditions for precipitation water
retention, i.e. areas where groundwater resources develop, feeding rivers, springs, and
water intakes. Areas with low permeability and built-up areas occupy approximately
a dozen percent of the area. The surface area of rivers, ponds, ditches – land under
waters slightly exceeds 2.0% of the area of Poland.
The factor directly affecting water resources are climatic conditions, particularly
precipitation and air temperature, determining the amount of evapotranspiration.
Despite a relatively small area, the basic parameters describing climate features
show high spatial and seasonal variability. In the territory of Poland, mean precipitation in the years 1901–2000 equalled 628 mm, and outflow 175.2 mm, providing the
outflow coefficient of 0.278 [7]. In a year with an average humidity, the amount of
precipitation in the territory of the country varied from approximately 500 mm in the
lowland belt to more than 1000 mm in the mountains. The highest monthly precipitation and evapotranspiration totals in Poland occur in July. The lowest precipitation
and evapotranspiration occur in January and February.