Namibia's geography: a dry country whose rivers run on its borders

How the land divides from the coast inland

Britannica describes the country as roughly rectangular, about 965 kilometres from north to south and 480 to 725 kilometres across, with a long, narrow extension to the east, the Caprivi Strip. It lies mostly between latitudes 17° and 29° south, and the Tropic of Capricorn cuts it about in half. Britannica divides it into three zones from west to east: the coastal Namib, the Central Plateau and the Kalahari. The Wikipedia article on the country's geography splits the same ground into five, adding the Great Escarpment between coast and plateau and the Bushveld of the north-east.

The rainfall figures are long-run averages from Britannica and the two Wikipedia articles, and the bands overlap.

The country's eastern arm has an odd origin. Britannica attributes the Caprivi Strip to a German belief that access to the Zambezi meant access to the Indian Ocean, despite the Victoria Falls downstream. At its tip, near Kazungula, Zimbabwe lies less than 200 metres away across the Zambezi.

What the Namib is made of

The desert gave the country its name, and the word itself is Khoekhoegowab, reported to mean a vast place or an area where there is nothing. The Namib runs the whole length of the coast. Its width depends on who is measuring: Britannica gives 50 to 80 miles, about 80 to 130 kilometres, over most of its length, the main Wikipedia article 100 to 200 kilometres, and the Wikipedia article on the desert itself 50 to 160 kilometres across a length of about 1,600 kilometres. In the north it narrows to almost nothing where the Kaokoveld, the western scarp of the plateau, comes down to the sea. Britannica describes it as partly rocky and, in its central stretch, dunes. The shoreline itself is mostly sand: the Wikipedia geography article gives 54% of its length as sandy beach, 28% as mixed sand and rock and 16% as rocky shore, behind which lie dune fields, lichen-covered gravel plains and scattered salt pans.

Where the sand comes from

The Namib Sand Sea along the central coast is built from sand carried a long way. The Wikipedia account traces most of it to the Orange River, which drops its load into the Atlantic south of the sand sea; onshore currents push it back to the shore and the prevailing south-west wind piles it into dunes, which is why the sand sea has been called the wind-displaced delta of the Orange. Near Sossusvlei several dunes exceed 300 metres. Where rivers block the sand's progress, the wind scours the ground into gravel plains instead.

UNESCO inscribed the Namib Sand Sea on the World Heritage List in 2013 as the only coastal desert with extensive dune fields influenced by fog. The property covers 3,077,700 hectares inside the Namib-Naukluft Park, with a buffer zone of 899,500 hectares, and consists of two dune systems, an older semi-consolidated one under a younger active one.

The same transport put diamonds on the coast. Britannica writes that they were probably washed down from the Basotho highlands by the Orange and are found at Oranjemund in the south; uranium is found at Arandis in the centre.

What lives on fog

The cold Benguela Current offshore meets warm air and produces a fog belt, and the Wikipedia article on the Namib records more than 180 days of thick fog a year in coastal areas. It also records more than a thousand wrecks on the Skeleton Coast. For plants and animals the fog is the water supply, and UNESCO calls it the primary source of water in the sand sea. The welwitschia grows two strap-shaped leaves for its whole life and draws moisture from the coastal fog. Darkling beetles known as fog beetles collect droplets on their backs, and one species builds water-catching webs.

People are few. The Topnaar Nama graze livestock along the Kuiseb River, Ovahimba and other Herero herders move between waterholes in the north, and much of the rest is conservation land. The Sperrgebiet in the south was closed to the public because of its diamonds.

How the plateau rises behind the escarpment

Inland from the Namib the ground climbs the Great Escarpment to over 2,000 metres. Temperatures and their daily range increase away from the cold sea, the fog thins, and summer winds forced over the scarp drop their moisture as rain, so the rocky escarpment carries woodland and acacia scrub that the desert below cannot.

The Central Plateau behind it holds Windhoek and, by the Wikipedia geography article, most of the population and economic activity. Brandberg, on the western escarpment, is the highest mountain; Britannica gives its height as 2,573 metres. Its summit is called Königstein, and the Wikipedia article on the country's geography gives 2,606 metres for it, the main Wikipedia article 2,573.

The plateau is not flat. The Fish River Canyon cuts into its south. The Fish River, which rises on the plateau and flows seasonally south to the Orange, is 650 kilometres long by the Wikipedia count. In the north the Etosha Pan lies dry and saline for most of the year and, in the wet season, holds a shallow lake of more than 6,000 square kilometres; game from the surrounding savanna gathers at the waterholes around it as the dry season advances.

East of the plateau the land slopes gently down into the Kalahari. Britannica notes that in the north hardpan and rock lie beneath the sand, and that with more river water and rain this makes both herding and cultivation possible there.

Why every permanent river lies on a border

Britannica names the permanent rivers: the Kunene, the Okavango, the Mashi, also called the Kwando, and the Zambezi on the northern border, and the Orange on the southern. Only the northern frontier, and not all of it, is readily passable. Every other river is seasonal.

The Swakop and the Kuiseb rise on the plateau, descend the escarpment and die out in the Namib, reaching the sea at Swakopmund and Walvis Bay only in rare flood years. Lesser rivers end in the sand of the Namib or the Kalahari. In the interior, surface water exists in summer, when rivers flood after exceptional rain, and otherwise in a few storage dams that hold back those floods.

The north has its own pattern. Rain falling in Angola flows into the Cuvelai-Etosha Basin and fills the oshanas, the Oshiwambo word for its flood plains. The annual flood, efundja, damages infrastructure and sometimes kills; the Wikipedia article records the floods of March 2011 as the worst, displacing 21,000 people.

Where the rain falls and when

The coast is cool and nearly rainless. Britannica gives under 50 millimetres a year and little difference between day and night or between seasons. Inland the daily range is wide, up to 30 °C on the plateau and in the Kalahari by the Wikipedia figure. Windhoek averages 24 °C in December, with an average maximum of 31 °C, and 13 °C in July, with an average maximum of 20 °C, in Britannica's figures.

The Wikipedia article grades the climate by rainfall from sub-humid, above 500 millimetres, through semi-arid and arid on the plateau and in the Kalahari, to hyper-arid, under 100 millimetres, on the coastal plain. In winter a hot, dry wind from the interior, called Bergwind in German and Oosweer in Afrikaans, sometimes blows down to the coast and raises sandstorms whose plumes over the Atlantic show on satellite images.

Rain comes in summer. The Wikipedia article describes a small rainy season from September to November and the main one from February to April, with a dry winter from June to August and more than 300 days of sunshine a year. The average across the country is about 350 millimetres, falling from about 600 millimetres in the Caprivi Strip to 50 millimetres or less at the coast. Rainfall varies widely from year to year, and multi-year droughts are common; in May 2019 Namibia declared a state of emergency over drought and extended it by six months in October 2019. Snow is rare enough to be news, and the last fall the Wikipedia article records was at the Spreetshoogte Pass in June 2011.

The World Bank's Climate Change Knowledge Portal puts the national average at 21.29 °C and 361.36 millimetres of rain a year over 1995 to 2014. Since 1970 temperatures have risen by 0.32 °C a decade in the ERA5 data it uses. Under the high-emission scenario SSP3-7.0 it projects a median warming of 1.7 °C by 2040 to 2059 against that baseline, with a median change in rainfall of minus 13.1 millimetres and a range wide enough to include a rise.

How Namibians find water underground

Groundwater can supply communities, mines, farms and tourism over nearly 80% of the country, by the Wikipedia account, and away from the border rivers and the dams it is the supply. The main Wikipedia article counts more than 100,000 boreholes drilled over the past century and the geography article more than 120,000; both say a third of them came up dry. Britannica records that overuse lowered the water table by as much as 100 feet, about 30 metres, in the twentieth century, both in the densely settled Ovambo north and in the commercial farming areas.

In 2012 an aquifer called Ohangwena II was found on both sides of the Angolan border. It was estimated to be able to supply 800,000 people in the north for 400 years at the 2018 rate of use. On 8 June 2023 Namibia acceded to the United Nations Water Convention on transboundary watercourses.

What the land can carry

Britannica estimates that less than 1% of the country is arable and that almost two thirds is suitable for grazing; the rest is mountain and desert, bush and wooded savanna and a small forest zone. Water, it says, and not soil fertility, is what limits farming. The best soils are in the north, in the Otavi Mountains, in parts of the plateau and in the Caprivi Strip.

Game shares the ranching zone with cattle and sheep. The parks are Etosha, the Skeleton Coast, Namib-Naukluft and the Sperrgebiet, and |Ai-|Ais and the Fish River Canyon Park joined South Africa's Richtersveld in 2003 as a transfrontier park. The Namib-Naukluft park alone covers 49,768 square kilometres, by the Wikipedia count. Article 95 of the constitution commits the state to maintaining ecosystems and biological diversity and to using living resources sustainably, and a programme funded from 1993 set out to give rural communities rights over the wildlife and tourism on their land.

The people are spread unevenly over this ground. The main Wikipedia article gives an average of 3.08 people per square kilometre in 2017, and Britannica places about half the population in the far north, where the rain is highest. Who lives where, and in what languages, is the subject of Namibia: culture.