Sian Lowland or Oversian basin ( uk, Надсіанська котловина) is a lowland located at the border between

Poland Poland, officially the Republic of Poland, , is a country in Central Europe. Poland is divided into Voivodeships of Poland, sixteen voivodeships and is the fifth most populous member state of the European Union (EU), with over 38 mill ...

and

Ukraine Ukraine ( uk, Україна, Ukraïna, ) is a country in Eastern Europe. It is the second-largest European country after Russia, which it borders to the east and northeast. Ukraine covers approximately . Prior to the ongoing Russian invas ...

along the

San River The San ( pl, San; uk, Сян ''Sian''; german: Saan) is a river in southeastern Poland and western Ukraine, a tributary of the river Vistula, with a length of (it is the 6th-longest Polish river) and a basin area of 16,877 km2 (14,42 ...

. Most of the region is located in Poland except for a small portion in southeastern end which is in Ukraine. The lowland is located between Malopolska Upland,

Carpathian Foothills Eastern Carpathian Foothills as a geographical term designates transitional region in the western parts of Ukraine and northeastern parts of Romania, between Eastern Carpathian Mountains to the southwest and number of plain regions to the east ...

Opillia Upland Opillia ( uk, Опілля, ) is a geographic region of the Podolian Upland in Lviv Oblast, Ivano-Frankivsk Oblast and Ternopil Oblast in western Ukraine. It is a western region of the Podillia Upland that stretches along the left bank of Dniester ...

and Roztochia. To the southeast it extends into

Dniester Lowland The Dniester, ; rus, Дне́стр, links=1, Dnéstr, ˈdⁿʲestr; ro, Nistru; grc, Τύρᾱς, Tyrās, ; la, Tyrās, la, Danaster, label=none, ) ( ,) is a transboundary river in Eastern Europe. It runs first through Ukraine and ...

over the Sian-Dniester Divide. The Sian Lowland is a

tectonic depression A structural basin is a large-scale structural formation of rock strata formed by tectonic warping of previously flat-lying strata. They are geological depressions, the inverse of domes. Elongated structural basins are also known as synclines. ...

along the foothills of the Carpathian Mountains filled in by

Miocene The Miocene ( ) is the first geological epoch of the Neogene Period and extends from about (Ma). The Miocene was named by Scottish geologist Charles Lyell; the name comes from the Greek words (', "less") and (', "new") and means "less recent" ...

strata In geology and related fields, a stratum ( : strata) is a layer of rock or sediment characterized by certain lithologic properties or attributes that distinguish it from adjacent layers from which it is separated by visible surfaces known as e ...

(up to thick) covered with

glacial A glacial period (alternatively glacial or glaciation) is an interval of time (thousands of years) within an ice age that is marked by colder temperatures and glacier advances. Interglacials, on the other hand, are periods of warmer climate betwe ...

and

alluvial deposit Alluvium (from Latin ''alluvius'', from ''alluere'' 'to wash against') is loose clay, silt, sand, or gravel that has been deposited by running water in a stream bed, on a floodplain, in an alluvial fan or beach, or in similar settings. Alluv ...

s. It consists of elevated plateaus (the tallest being Tarnohorod) dissected by the valleys of rivers, such as the Tanew River, the Liubachivka River, the Shklo River, and the Vyshnia River. Loess can be found in parts of the plateaus, and dunes are situated in some of its sandy reaches. A large proportion of the lowland's forests have been cleared out, although pine forests mixed with

fir Firs (''Abies'') are a genus of 48–56 species of evergreen coniferous trees in the family Pinaceae. They are found on mountains throughout much of North and Central America, Europe, Asia, and North Africa. The genus is most closely related to ...

s and birches occur in the region's sandy areas, and fir forests mixed with

hornbeam Hornbeams are hardwood trees in the flowering plant genus ''Carpinus'' in the birch family Betulaceae. The 30–40 species occur across much of the temperate regions of the Northern Hemisphere. Origin of names The common English name ''hornb ...

s and maples grow in its heavier soils. The lowland has a population density of 80 persons/km²; the population is predominantly (75%) rural.

External links

Sian Lowland
at

Encyclopedia of Ukraine The ''Encyclopedia of Ukraine'' ( uk, Енциклопедія українознавства, translit=Entsyklopediia ukrainoznavstva), published from 1984 to 2001, is a fundamental work of Ukrainian Studies. Development The work was crea ...

Plains of Poland Plains of Ukraine East European Plain {{Ukraine-geo-stub