Dnipro Lowland

Dnipro Lowland [Придніпровська низовина; Prydniprovska nyzovyna]. An extensive plain occupying most of Left-Bank Ukraine between the Dnipro River in the west and southwest and the Central Upland in the northeast. In the southeast it is bounded by the Ukrainian Crystalline Shield along the Samara River and by the Donets Ridge. The boundary between the Dnipro Lowland and the Central Upland runs approximately through Kharkiv, Sumy, Putyvl, Hlukhiv, and Seredyna-Buda. The southwestern boundary with the Dnipro Upland is a natural one, while the northwestern boundary with the Polisia Lowland is fluid. The northern part of the Dnipro Lowland, which lies within the forest belt (south of the Kyiv–Nizhyn–Hlukhiv line), is usually considered to be a part of eastern (or Chernihiv) Polisia. The lowland is about 600 km long, about 250 km wide in the north, and 150 km wide in the south. It encompasses Poltava oblast and Chernihiv oblast and parts of Kyiv oblast, Sumy oblast, Kharkiv oblast, Cherkasy oblast and Dnipropetrovsk oblast, covering an area of over 100,000 sq km; excluding the part in Polisia, it covers 75,000 sq km.

The lowland lies within the Dnipro-Donets Trough, and this determines its orographic characteristics. The Precambrian foundation of the trough is 8–10 km below the surface and contains large sedimentary deposits from the Paleozoic to the Cenozoic period. Chalk strata (in the north and southeast) up to 600 m deep and Paleogene strata (mainly sand and clay) 250–300 m deep come to the surface in the river valleys. The lowland became dry land at the end of the Paleogene period. The Dnipro River Valley and its left-bank tributaries already existed at the time. Erosion has greatly affected the relief of the lowland; it is now covered with a layer of Anthropogene deposits that lie unevenly on the washed-out Paleogene strata.

The lowland was covered by a glacier during the Dnipro or Riss glaciation, which extended south to the mouth of the Orel River, east just beyond the Psol River, and north to the watershed between the Psol and the Sula River. Climatic changes before, during, and after this age left their mark on the landscape of the lowland. The glaciers left many ground and terminal moraines, with irregular hills. They also left sand and gravel plains formed by the glacial meltwaters, which receded with difficulty, because the Dnipro River had to penetrate through the rising Crystalline Shield. The ice waters flowed along depressions on the edge of the glacier. Loess deposits formed before, during, and after the glaciation. Because of climatic changes and alternations between accumulation and erosion, the loess lies in several layers separated by ancient (concealed) chernozem soils. A series of terraces were formed. The southern part of the lowland is covered with loess and has an eroded, gullied topography. The northern part is not covered with loess and has a glacial topography. But the line separating these two types of landscape is not as distinct in the lowland as it is in the Dnipro Upland: in Polisia the lowland contains many loess islands with an eroded landscape, while the Dnipro Valley has a typical Polisian landscape for a considerable distance south.

Although the Quaternary layers of the lowland reach a thickness of 50 m, and even 100 m in places, the preglacial features of the relief have remained basically unchanged. The surface of the lowland slopes southwest towards the axis of the Dnipro-Donets Trough. Its highest elevation (in the northeast) is over 200 m, and its lowest—where the Samara River joins the Dnipro River—is 40 m. The tributaries of the Dnipro River—the Desna River, the Sula River, the Psol River, the Vorskla River, the Orel River, the Samara River, and other smaller rivers—flow towards the southwest. Only the most southeastern part of the lowland slopes towards and has waters flowing into the Donets River.

The lowland in the forest-steppe belt has two basic regions: the Dnipro Terraced Plain (sometimes called the Dnipro-Desna Terraced Plain) in the southwest, with a lower elevation, and the Poltava Plain in the northeast, with a higher elevation.

The Dnipro Terraced Plain is the broad valley of the Dnipro River. It stretches northeast as far as the line running through Hlukhiv, Pryluky, Pyriatyn, Khorol, and the mouth of the Samara River. Up to 130 km wide in the north, it narrows to 20 km in the south. The plain has almost no forest and consists of several wide terraces: alluvial, wooded, and loess.

The alluvial terrace is prominent and extends the full length of the Dnipro River. It is 4–5 m high, several kilometers wide, and 15–20 m thick. The terrace is covered with lakes, swamps, meadows, and bush, but rarely with forest. It is usually inundated by the Dnipro during floods. Since the construction of the Dnipro Cascade of Hydroelectric Stations, most of this terrace has been under water.

The second, wooded terrace rises to 10–15 m above the Dnipro riverbed and is up to 10 km wide. Consisting of sands, it was once covered by pine forests. Today it is mostly deforested and partly covered with friable sand and dunes.

The higher part of the Dnipro Terraced Plain (two to four terraces) rises above the lower terraces at a sharp incline of 20–25 m and is covered with loess. These terraces are 90 km wide in the north and 20 km wide in the south. They constitute a sedimentary plain, which is divided by a few wide, swampy tributaries of the Dnipro River. The valley of the Trubizh River (where the Dnipro flowed in the Riss period) forms a wide depression in the landscape. A few isolated hills—Khotskyi Horb (151 m), Pyvykha (169 m), Kalytva Ridge (145 m)—are relicts of the terminal moraine of the Dnipro glacier.

The Poltava Plain rises distinctly above the Dnipro Terraced Plain along a line running through Ichnia, Pyriatyn, Khorol, and Novomoskovsk and above the Desna Terraced Plain along a line running from Ichnia to the Sula River–Seim River watershed. It rises gradually towards the northeast, where at 200–220 m it becomes the Central Upland. The entire plain is covered with thick layers of loess, which in the west overlie a glacial base and in the east lie directly on Tertiary deposits, which are exposed only in river valleys. The surface of the Poltava Plain is cut by the left-bank tributaries of the Dnipro River, which form asymmetrical valleys 70–80 m deep and 10–12 km wide. The right banks of the rivers are high and steep, gouged by short but deep ravines with landslips, and covered often with bush and forest. Their left banks rise gently, usually in three to four terraces. Gullies of the left banks branch out onto the surfaces of watersheds and form deep, short furrows. The gullies on the right banks leave long, shallow furrows in the watersheds, giving them an undulating character.

The typical gully and ravine landscape that prevails in the Poltava Plain can be attributed mainly to the soft loess foundation. The plain is divided unequally: the right banks of the Sula River, Khorol River, Vorskla River, and the middle Psol River valleys are cut most prominently. Some variety on the watershed plains is provided by glacial (dead) valleys, which dissect the watersheds and connect the main river valleys of the Poltava Plain. Pody (saucerlike depressions) are widespread in the south. The central section contains hills caused by the movement of saline masses; for example, Zolotukha Mountain near Romny and Vysachky Hill in Poltava oblast. Burial mounds (usually 6–8 m high), often arranged in long rows, dot the landscape and are relicts of ancient civilizations. Three basic relief forms are found in the northern, Polisian zone of the lowland: alluvial plains and terraced valleys, moraine and sandy outwash plains, and dissected loess plains.

The southern part of the Polisian zone is a continuation of the Dnipro Terraced Plain. Besides a low outwash terrace, there are two quite extensive higher terraces, covered mostly with sand (not loess). Farther north the three types of relief mentioned above exist side by side. Alluvial plains and terraced plains extend along the Dnipro River, the Desna River, the Snov River, and other rivers. Moraine and sandy outwash plains lie on the watersheds. Loess islands, marked by gullies, are widespread here; they include the Liubech–Chernihiv, Berezna–Sosnytsia, Novhorod-Siverskyi, and other islands. An important role in forming the present surface was played by the old, sedimentary valleys. The largest among them is the Zamhlai Valley, which at one time contained the waters of the Dnipro. Now it is a large, swampy depression (8,330 ha in area).

The northeastern part of the lowland, which is sometimes called Novhorod-Siverskyi Polisia, passes into the Central Upland. Here chalk layers covered with thin Tertiary and Anthropogene deposits rise to the surface. The rivers cut into the chalk layers, forming many ravines and gullies, or a karstic relief. The right bank of the Desna River near Novhorod-Siverskyi is particularly picturesque.

The climate of the lowland is temperate-continental. The continental character is intensified in the southeastern direction with increasing annual-temperature ranges and higher summer temperatures. The average annual temperature is 6 to 7.5 °C, the average January temperature –6 to –7.5 °C, and the average July temperature 18.5 to 21 °C. The difference between the coldest and warmest months increases from 25 °C in the northwest to 28 °C in the southeast. The annual rainfall diminishes from 600 mm in the north to 450 mm in the southeast. Seventy-five percent of the rainfall comes in the warmer half of the year.

In the forest-steppe section of the lowland chernozem soils predominate. Deep chernozems, poor humus, and chernozem-meadow soils are widespread. Along the steep right river banks are found degraded chernozems and gray forest podzolized soils. In the northern part of the lowland bog-podzol soils predominate, but gray and light gray podzol soils (usually on a loess foundation) and peat-bog soils are also common.

Two-thirds of the lowland lies within the forest-steppe belt. Only about 6 percent of the area is covered with forests, mostly oak forests with some linden and pine forests on sandy terraces. The grassy, colored, broad-leafed steppe is completely under cultivation. The southernmost part of the lowland enters the fescue-feather-grass steppe belt. In the part of the lowland that lies in Polisia, now barely 17 percent of the area is covered with forest. The forests are partly deciduous (oak, birch, ash, alder, etc) and partly coniferous (pine). Much of the land is covered with dry and water meadows. Sedges, reeds, and cattails grow in the swamps (see Common Reed, Cattail, Sedge).

(For the population and economy of the Dnipro Lowland, see Poltava oblast and Chernihiv oblast.)

BIBLIOGRAPHY
Bondarchuk, V. Heomorfolohiia URSR (Kyiv 1949)
Geologiia SSSR 5: Ukrainskaia SSR (Moscow 1958)
Chyzhov, M. Ukraïns'kyi Lisostep (Kyiv 1961)
Zamorii, P. Chetvertynni vidklady Ukraïns'koï RSR, part 1 (Kyiv 1961)
Marynych, O. Ukraïns'ke Polissia (Kyiv 1962)
Tsys', P. Heomorfolohiia URSR (Lviv 1962)
Bondarchuk, V. Heolochichna budova Ukraïns'koï RSR (Kyiv 1963)
Lan'ko, A.; Marynych, O.: Shcherban', M. Fizychna heohrafiia Ukraïns'koï RSR (Kyiv 1969)

Volodymyr Kubijovyč

[This article originally appeared in the Encyclopedia of Ukraine, vol. 1 (1984).]