Belarus's geography: a glacial plain that keeps its water

How the last ice sheet laid out Belarus

The relief of Belarus is the work of ice. Britannica attributes most of the country's topography to glaciation during the Pleistocene, the epoch that ended about 11,700 years ago, and what the ice left is a plain of flat lowlands broken by low hills with level tops. More than half the surface lies below 200 metres. Wikipedia puts the average elevation at 160 metres, the lowest point at 90 metres on the Neman and the highest, Dzyarzhynskaya Hara, at 345 metres. Britannica gives the same summit as 346 metres. The record on this site carries 345.

The higher ground is moraine, the rock debris pushed forward and dropped by the Valday glaciation, which was the last advance of Pleistocene ice in eastern Europe. The largest ridge of it, the Belarusian Ridge, runs northeast from the Polish border in the southwest to a point north of Minsk. There it widens into the Minsk Upland before turning east to join the Smolensk-Moscow Upland in Russia. A second line, the Ashmyany Upland, is built of terminal moraines from the same glacial period and runs across the main ridge between Minsk and Vilnius, in Lithuania. The tops of these ridges are flat or gently rolling, covered in light sandy podzolic soils, and largely cleared of the forest that once stood on them.

Between the ridges lie wide lowlands, mostly poorly drained, marshy and scattered with small lakes. North of the main line of hills the Polatsk Lowland takes up the north of the country, and the Neman Lowland its northwestern corner around Hrodna. South of the Belarusian Ridge the Central Byarezina Plain is very flat and slopes gently south until, in Britannica's word, it merges "imperceptibly" with the Pripet Marshes.

The country these features sit in measures about 560 kilometres from north to south and 650 kilometres from west to east, between latitudes 51° and 57° north. Its area is 207,600 square kilometres, of which 2.26% is water. Lithuania and Latvia lie to the northwest, Russia to the north and east, Ukraine to the south and Poland to the west, and none of the boundary touches the sea. With no coast and almost no height, the country is mapped most usefully by where its water goes.

Where the rivers of Belarus choose between two seas

The moraine ridges are low, and they still divide the country's water. The greater part of Belarus lies in the basin of the Dnieper, which crosses the country from north to south on its way to the Black Sea, and in the basins of its main tributaries: the Byarezina and the Pripet on the right bank, the Sozh on the left. The north drains the other way. The Western Dvina carries the water of the Polatsk Lowland to the Baltic, and the Neman takes the west to the same sea. In the far southwest the Mukhavyets flows into the Bug, which forms part of the border with Poland and also ends in the Baltic.

At one point the two drainages were joined on purpose. A ship canal links the Mukhavyets with the Pripet, so a vessel can pass from the Baltic basin into the Black Sea basin across Belarusian territory. The divide itself runs through the Białowieża Forest on the Polish border, which UNESCO describes as lying on the watershed of the Baltic Sea and the Black Sea.

The rest of the water is a matter of counting, and the counts differ by source. Britannica records more than 20,000 streams with a combined length of about 90,600 kilometres, and more than 10,000 lakes. Wikipedia gives 11,000 lakes. Britannica names Narach, Osveyskoye and Drysvyaty. The rivers are generally frozen from December to late March, and the thaw is followed by about two months of maximum flow.

What lies under the Pripet Marshes

How meltwater sand filled the Pripet trough

South of the Belarusian Ridge the land drops into Palyessye, the Belarusian name for the Pripet Marshes, which Britannica glosses as "Woodlands". The marshes occupy a structural trough in the basin of the Pripet, and the trough is filled with outwash sands and gravels, carried there by meltwater from the same glaciation that built the ridges to the north. They continue south across the border into Ukraine, closed in by the Belarusian Ridge on the north and by the Volyn-Podilsk and Dnieper uplands on the south.

Britannica's entry on the marshes, revised in 2011, gives the region an area of approximately 270,000 square kilometres. That exceeds the 207,600 square kilometres of Belarus as a whole, so the figure measures a lowland region spread over two countries, pine forest and sand included, and says nothing about how much of it is open bog.

The region stays wet because average annual precipitation there, 550 to 650 millimetres, exceeds evaporation, groundwater lies close to the surface, and the rivers run in shallow beds with wide floodlands. Tributaries of the Pripet, including the Stokhid, Styr, Horyn, Ubort, Yaselda and Ptich, bring water down into the swamps from the higher ground around them, and at the spring snowmelt they overflow their low banks. Huge marshes line the Pripet itself, the Pinsk Marshes mark its middle course, and the many lakes of the region are, in Britannica's description, in various stages of choking up into further bog.

How the state set out to drain it

About one third of the region is forested, with pine, birch, alder, oak, aspen, white spruce and hornbeam. Drainage as a state project began in 1872 with a "western expedition for the drainage of swamps" led by the Russian scholar I. I. Zhilinsky, and a vast amount of reclamation followed in the 20th century. The methods were regulated drainage, reservoirs on the rivers, straightened river channels, trees planted on the sandy uplands and the clearing of unwanted vegetation. Where the land was converted it grows rye, barley, wheat, flax, hemp, potatoes, vegetables and fodder grasses.

Part of what stayed wet is now under international designation. The Ramsar Convention's map of Belarus, consulted in September 2026, marked 26 wetland sites. They include the Sporovsky Biological Reserve, Zvanets, the Olmany Mires Zakaznik, the Mid-Pripyat State Landscape Zakaznik, Pripyatsky National Park and the Polesye Valley of the River Bug, along with Yelnia, whose raised bog carries the carnivorous sundew. Belarus extended the Morochno site in 2017.

Why the soils of Belarus reward drainage

About three fifths of Belarus is covered by podzolic soils, and they divide along the same line as the relief. On the uplands they are mainly clay loams formed on loess, which can be productive with fertiliser. On the plains and lowlands they are mostly sandy podzols of low fertility, interspersed with swampy clays that are high in humus and can be very fertile once drained. That last property is the agronomic case for the reclamation of the south.

Clearing began long before drainage. Farming removed the greater part of the primeval forest over the centuries, and the deciduous trees went first because they prefer the richer soils. The forest of the uplands had largely been removed by the late 16th century, and the moraine ridges are still described as mostly cleared.

Below the surface the resources are modest and mostly loose. Wikipedia lists peat deposits, small quantities of oil and natural gas, granite, dolomite, marl, chalk, sand, gravel and clay. Peat is the one the terrain explains. It is the accumulated marsh, and after 1986 burning locally produced peat and wood was itself believed to carry a radiation risk.

How the climate shifts from Brest to Vitebsk

The two main reference works describe the same climate in different terms. Wikipedia classifies Belarus as hemiboreal and places it in the transitional zone between continental and maritime climates. Britannica calls it cool continental, moderated by maritime influence from the Atlantic. Both descriptions come down to a gradient that runs from the southwest to the northeast.

January minimums range from about −4 °C at Brest in the southwest to about −8 °C at Vitebsk in the northeast, and thaw days are frequent through the winter. The frost-free period shortens along the same line, from more than 170 days in the southwest to 130 in the northeast. Summers are cool and moist, with an average temperature around 18 °C.

Britannica gives rainfall of about 530 millimetres a year on the lowlands and some 700 on the higher moraine ridges, with the maximum from June to August. Wikipedia gives a national range of 550 to 700 millimetres. Those are moderate totals. In the Pripet basin they are enough to keep the ground saturated, because precipitation there exceeds evaporation and the land has almost no fall to carry the surplus away.

Which forests of Belarus outlasted the clearing

Forest covered about 43% of Belarus in 2020, 8,767,600 hectares against 7,780,000 in 1990, by the figures Wikipedia reports. Of the 2020 total, 6,555,600 hectares was naturally regenerating and 2,212,000 had been planted. About 2% of the naturally regenerating forest was classed as primary, meaning native species with no clearly visible sign of human activity, and around 16% of the forest area lay inside protected areas. In 2015 all of it was reported to be in public ownership.

The make-up of the forest changes with latitude. Pine and spruce predominate in the north, and southward the share of oak and hornbeam rises. Birch grows everywhere, often as the first growth on burned or disturbed ground. Wikipedia assigns the country to two ecoregions, the Sarmatic mixed forests and the Central European mixed forests.

Why Białowieża survived on the Polish border

The one natural World Heritage property in Belarus runs across the western border into Poland. Białowieża National Park in Poland was inscribed on the World Heritage List in 1979, the listing was extended to Belovezhskaya Pushcha in Belarus in 1992, and a large extension in 2014 produced a property of 141,885 hectares with a buffer zone of 166,708 hectares. The forest was kept for centuries as a private hunting ground, first of the Polish kings and later of the Russian tsars, and became a nature reserve and then a national park on both sides of the frontier.

UNESCO records 59 mammal species, over 250 bird species, 13 amphibians, 7 reptiles and over 12,000 invertebrate species in the property. Its European bison numbered approximately 900 across the whole property in UNESCO's description as consulted in September 2026. The species had become extinct in the wild after the First World War and was brought back through captive breeding. UNESCO lists roads, firebreaks and the border fence among the barriers that divide the forest, and notes that the wet meadows and river corridors inside it need active management because water flow has decreased and the hay cutting that farming once supplied has stopped.

Elsewhere in Belarus the forests hold elk, deer and wild boar, with beaver along the rivers, and grouse, partridge, woodcock, snipe and duck among the birds.

How the Chernobyl fallout settled into Belarusian ground

What fell on Belarus from Chernobyl

The Chernobyl nuclear power plant stood in the Ukrainian SSR, 16 kilometres beyond the Belarusian border. When its fourth reactor exploded in April 1986, about 70% of the fallout landed on the Byelorussian SSR, by the figure Wikipedia gives. The Chernobyl Forum, which brought eight UN bodies together with the governments of Belarus, Russia and Ukraine from 2003 to 2005, found that more than 200,000 square kilometres of Europe had received caesium-137 above 37 kilobecquerels per square metre, and that over 70% of that area lay in the three countries. The deposit was very uneven. It was heaviest where rain was falling as the contaminated air passed over.

About a fifth of Belarusian land was affected, principally farmland and forest in the southeastern regions, and Britannica reports that about one fifth was still radioactively contaminated in the early 21st century. The IAEA gives the half-lives: 8 days for iodine, 29 years for strontium-90 and 30 years for caesium-137, so the first has long decayed and the other two are still in the soil.

Soviet authorities drew their lines on the ground itself. According to the OECD Nuclear Energy Agency, 1,480 kilobecquerels of caesium-137 per square metre was the criterion for permanent resettlement of a population, and 555 to 1,480 for temporary relocation.

Why the terrain kept the caesium moving

The Forum's findings read like a description of the Belarusian lowlands. Remediation remained justified, it concluded, mainly in farming areas with poor sandy and peaty soils, where caesium passes readily from soil into plants. Among long-term measures it rated the draining of wet peaty areas as very effective, which turned the reclamation technique of the Pripet basin into a radiological one. Wikipedia adds caesium binders and rapeseed cultivation to the methods used in Belarus to lower caesium-137 in the soil.

Forests hold the caesium longer than fields. In some areas of Belarus, Russia and Ukraine the Forum found that forest foods had become the main route of internal exposure, and expected that to continue for several decades. Rivers, open lakes and reservoirs carried low levels, while in some closed lakes, those with no stream flowing out, the water and fish were expected to stay contaminated for decades. Belarus has more than 10,000 lakes, so that distinction between lakes with an outlet and lakes without one applies across much of the country.

In its 2005 findings the Forum reported that parts of the Gomel and Mogilev regions could still produce milk with caesium-137 above the national action level of 100 becquerels per kilogram. Across the three countries 784,320 hectares of agricultural land had been taken out of use and timber production halted on 694,200 hectares of forest, and in Belarus, the Forum noted, some of the best arable land was removed from production. Because burning locally produced wood and peat was believed to carry a risk, many villages were connected to gas instead, and 8,980 kilometres of gas pipeline were laid in the three countries in the fifteen years after the accident.