South Africa forms a distinct region, or subcontinent, divided from the rest of Africa by the rivers that mark its northern border. In the northwest, the Orange River cuts through the Namib Desert and divides South Africa from Namibia. In the east, the Limpopo River traverses large areas of arid grassland along the common border with Zimbabwe and southeastern Botswana. Between these two, the Molopo River winds through the southern basin of the Kalahari Desert, also dividing South Africa from Botswana. Populations have moved across these rivers almost continuously over the centuries, but, in general, the northern border region of South Africa is sparsely populated.

The geological substratum of the subcontinent was formed at least 3.8 billion years ago, according to geologists, and most of the country's natural features evolved into their present form more than 200 million years ago. Especially since the early twentieth-century writings of Alfred Wegener, geologists have hypothesized that South Africa was once part of a large land mass, now known as Gondwana, or Gondwanaland, that slowly fractured along the African coastline millions of years ago. Theories of such a supercontinent are bolstered by geological continuities and mineral similarities between South Africa and South America, by fossil similarities between South Africa and the Indian Ocean island of Madagascar, and by the sharp escarpments, or geological fractures, that encircle most of southern Africa near the coast.

The ancient rock substratum is overlain by sedimentary and volcanic rock formations. Because ground cover is sparse, only about 11 percent of the land in South Africa is arable. More than 20 percent of the land is too arid or the soil is too poor for any agricultural activity without irrigation; roughly 66 percent is suitable only for livestock grazing. Even the thin soil cover has been severely eroded, especially in the country's most overpopulated and impoverished rural areas. The relatively poor land conceals enormous wealth in minerals, however, including gold, diamonds, copper, platinum, asbestos, and coal.

Geographic Regions

Like much of the African continent, South Africa's landscape is dominated by a high plateau in the interior, surrounded by a narrow strip of coastal lowlands. Unlike most of Africa, however, the perimeter of South Africa's inland plateau rises abruptly to form a series of mountain ranges before dropping to sea level. These mountains, known as the Great Escarpment, vary between 2,000 meters and 3,300 meters in elevation. The coastline is fairly regular and has few natural harbors. Each of the dominant land features--the inland plateau, the encircling mountain ranges, and the coastal lowlands--exhibits a wide range of variation in topography and in natural resources.

The interior plateau consists of a series of rolling grasslands ("veld," in Afrikaans), arising out of the Kalahari Desert in the north. The largest subregion in the plateau is the 1,200-meter to 1,800-meter-high central area known as the Highveld. The Highveld stretches from Western Cape province to the northeast, encompassing the entire Free State (formerly, Orange Free State). In the north, it rises into a series of rock formations known as the Witwatersrand (literally, "Ridge of White Waters" in Afrikaans, commonly shortened to Rand--see Glossary). The Rand is a ridge of gold-bearing rock, roughly 100 kilometers by thirty-seven kilometers, that serves as a watershed for numerous rivers and streams. It is also the site of the world's largest proven gold deposits and the country's leading industrial city, Johannesburg.

North of the Witwatersrand is a dry savanna subregion, known as the Bushveld, characterized by open grasslands with scattered trees and bushes. Elevation varies between 600 meters and about 900 meters above sea level. The Bushveld, like the Rand, houses a virtual treasure chest of minerals, one of the largest and best known layered igneous (volcanic) mineral complexes in the world. Covering an area roughly 350 kilometers by 150 kilometers, the Bushveld has extensive deposits of platinum and chromium and significant reserves of copper, fluorspar, gold, nickel, and iron.

Along the northern edge of the Bushveld, the plains rise to a series of high plateaus and low mountain ranges, which form the southern edge of the Limpopo River Valley in Northern Province. These mountains include the Waterberg and the Strypoortberg ranges, and, in the far north, the Soutpansberg Mountains. The Soutpansberg range reaches an elevation of 1,700 meters before dropping off into the Limpopo River Valley and the border between South Africa and Zimbabwe. The Kruger National Park, which is known for its diverse terrain and wildlife, abuts most of the north-south border with Mozambique.

West of the Bushveld is the southern basin of the Kalahari Desert, which borders Namibia and Botswana at an elevation of 600 meters to 900 meters. Farther south, the Southern Namib Desert stretches south from Namibia along the Atlantic coastline. Between these two deserts lies the Cape Middleveld subregion, an arid expanse of undulating plains that sometimes reaches an elevation of 900 meters. The Cape Middleveld is also characterized by large depressions, or "pans," where rainfall collects, providing sustenance for a variety of plants and animals.

The southern border of the Highveld rises to form the Great Escarpment, the semicircle of mountain ranges roughly paralleling South Africa's coastline. The Drakensberg Mountains, the country's largest mountain range, dominate the southern and the eastern border of the Highveld from the Eastern Cape province to the border with Swaziland. The highest peaks of the Drakensberg Mountains in KwaZulu-Natal exceed 3,300 meters and are even higher in Lesotho, which is known as the "Mountain Kingdom."

In the west and the southwest, the Cape Ranges, the country's only "fold mountains"--formed by the folding of the continental crust--form an "L," where the north-south ranges meet several east-west ranges. The north-south Cape Ranges, paralleling the Atlantic coastline, include the Cedarberg Mountains, the Witsenberg Mountains, and the Great Winterhoek Mountains, and have peaks close to 2,000 meters high. The east-west ranges, paralleling the southern coastline, include the Swartberg Mountains and the Langeberg Mountains, with peaks exceeding 2,200 meters.

The Cape Ranges are separated from the Highveld by a narrow strip of semidesert, known as the Great Karoo (Karoo is a Khoisan term for "land of thirst"). Lying between 450 meters and 750 meters above sea level, the Great Karoo is crossed by several rivers that have carved canyons and valleys in their southward descent from the Highveld into the ocean. Another narrow strip of arid savanna lies south of the Great Karoo, between the Swartberg Mountains and the Langeberg Mountains. This high plain, known as the Little Karoo, has a more temperate climate and more diverse flora and fauna than the Great Karoo.

The narrow coastal strip between the Great Escarpment and the ocean, called the Lowveld, varies in width from about sixty kilometers to more than 200 kilometers. Beyond the coastline, the continental shelf is narrow in the west but widens along the south coast, where exploitable deposits of oil and natural gas have been found. The south coast is also an important spawning ground for many species of fish that eventually migrate to the Atlantic Ocean fishing zones.

Lakes and Rivers

Water shortages are a chronic and severe problem in much of South Africa. The country has no commercially navigable rivers and no significant natural lakes. Along the coastline are several large lagoons and estuarine lakes, such as Lake Saint Lucia in KwaZulu-Natal. The government has created several artificial lakes, primarily for agricultural irrigation.

South Africa's largest river, the Orange River, rises in the Drakensberg Mountains and flows to the west and northwest, draining the highlands of Lesotho before being joined by the Caledon River between the Eastern Cape province and the Free State. The Orange River forms the border with Namibia before emptying into the Atlantic Ocean.

The major tributary of the Orange River, the Vaal ("foul"--for its murky cast) River, rises in the Drakensbergs and flows westward, joining the Orange River from the north in Northern Cape province. Together, the Orange and the Vaal rivers drain almost two-thirds of the interior plateau of South Africa. Other major rivers are the Breede River, the Komati River, the Olifants River, the Tugela River, and the Umzimvubu River, which run fairly short distances from the interior plateau to the ocean, and the Limpopo and Molopo rivers along the northern border with Botswana and Zimbabwe.

Climate and Rainfall

Climatic conditions generally range from Mediterranean in the southwestern corner of the country to temperate in the interior plateau, and subtropical in the northeast. A small area in the northwest has a desert climate. Most of the country has warm, sunny days and cool nights. Rainfall generally occurs during summer (November through March), although in the southwest, around the Cape of Good Hope, rainfall often occurs in winter (June through August). Temperatures are influenced by variations in elevation, terrain, and ocean currents more than latitude.

Temperature and rainfall patterns vary in response to the movement of a high-pressure belt that circles the globe between 25° and 30° south latitude during the winter and low-pressure systems that occur during summer. There is very little difference in average temperatures from south to north, however, in part because the inland plateau rises slightly in the northeast. For example, the average annual temperature in Cape Town is 17°C, and in Pretoria, 17.5°C, although these cities are separated by almost ten degrees of latitude. Maximum temperatures often exceed 32°C in the summer, and reach 38°C in some areas of the far north. The country's highest recorded temperatures, close to 48°C, have occurred in both the Northern Cape and Mpumalanga (formerly Eastern Transvaal).

Frost occurs in high altitudes during the winter months. The coldest temperatures have been recorded about 250 kilometers northeast of Cape Town, where the average annual minimum temperature is -6.1°C. Record snowfalls (almost fifty centimeters) occurred in July 1994 in mountainous areas bordering Lesotho.

Climatic conditions vary noticeably between east and west, largely in response to the warm Agulhas ocean current, which sweeps southward along the Indian Ocean coastline in the east for several months of the year, and the cold Benguela current, which sweeps northward along the Atlantic Ocean coastline in the west. Air temperatures in Durban, on the Indian Ocean, average nearly 6°C warmer than temperatures at the same latitude on the Atlantic Ocean coast. The effects of these two currents can be seen even at the narrow peninsula of the Cape of Good Hope, where water temperatures average 4°C higher on the east side than on the west.

Rainfall varies considerably from west to east. In the northwest, annual rainfall often remains below 200 millimeters. Much of the eastern Highveld, in contrast, receives 500 millimeters to 900 millimeters of rainfall per year; occasionally, rainfall there exceeds 2,000 millimeters. A large area of the center of the country receives about 400 millimeters of rain, on average, and there are wide variations closer to the coast. The 400-millimeter "rainfall line" has been significant because land east of the rainfall line is generally suitable for growing crops, and land west of the rainfall line, only for livestock grazing or crop cultivation on irrigated land.

Environmental Trends

South Africa has a wealth of natural resources, but also some severe environmental problems. The mainstay of the economy, the mining industry, has introduced environmental concerns, and mineowners have taken some steps in recent years to minimize the damage from this enterprise (see Environmental Protection and Tourism, ch. 3). Agriculture suffers from both land and water shortages, and commercial farming practices have taken a toll on the land. Energy production, too, has often contributed to environmental neglect.

Because of the generally steep grade of the Great Escarpment as it descends from the interior to the coastal lowlands, many of South Africa's rivers have an unusually high rate of runoff and contribute to serious soil erosion. In addition, water consumption needs and irrigation for agriculture have required building numerous dams. As of the mid-1990s, the country has 519 dams with a total capacity of 50 billion cubic meters. Water management engineers estimate that the Vaal River, which provides most of the water for the industrial hub around the Witwatersrand, has reached its maximum capacity for water utilization.

The Lesotho Highlands Water Project, the largest hydroelectric project ever undertaken in Africa, is a thirty-year joint endeavor between South Africa and Lesotho that is due for completion in the year 2020. Through a series of dams on the headwaters of the Orange River, it will alleviate water shortages in South Africa and is expected to provide enough electrical power to enable Lesotho to become virtually self-sufficient in energy.

Much of the land in South Africa has been seriously overgrazed and overcultivated. During the apartheid era, black African farmers were denied many government benefits, such as fertilizers, which were available to white farmers. Settlement patterns, too, have contributed to land degradation, particularly in overcrowded black homelands, and the inadequate and poorly administered homelands' budgets have allowed few improvements in land use.

The environmental impacts of the mining industry have been devastating to some areas of the Witwatersrand, the country's most densely populated region. Some of the gold deposits located here have been mined for more than a century. According to South African geographer Malcolm Lupton and South African urban planning expert Tony Wolfson, mine shafts--the deepest is 3,793 meters--have made hillsides and ridges less stable. Pumping water from subterranean aquifers has caused the natural water table to subside, and the resulting cavities within the dolomite rock formations that overlie many gold deposits sometimes collapse, causing sinkholes. Moreover, these impacts of the mining industry could worsen over time.

Industrial wastes and pollutants are another mining-related environmental hazard. Solid wastes produced by the separation of gold from ore are placed in dumps, and liquid wastes are collected in pits, called slimes dams. Both of these contain small amounts of radioactive uranium. Radon gas emitted by the uranium poses a health threat when inhaled and can contribute to lung cancer and other ailments. Furthermore, the dust from mine dumps can contribute to respiratory diseases, such as silicosis.

Acids and chemicals used to reduce the ore to gold also leave dangerous contaminants in the water table. Streams around Johannesburg townships, such as Soweto, have been found to contain uranium, sulfates, cyanide, and arsenic. Land near mining operations is sometimes rendered "sterile" or too contaminated for farming, and efforts to reclaim the land have often proved too costly for industry or government.

Air pollution is a serious problem in some areas. Most homes lack electricity in the mid-1990s, and coal is used for cooking and heating. Air-quality tests have revealed high levels of particulate pollution, as a result, especially during cold weather. The World Health Organization (WHO) reported in the early 1990s that air-quality measurements in Soweto and surrounding townships outside Johannesburg exceeded recommended levels of particulate pollution for at least three months of the year. Other studies suggest that air pollution contributes to child health problems, especially respiratory ailments, in densely populated areas.

Electricity for industrial and commercial use and for consumption in urban areas is often produced in coal-burning power stations. These electric power stations lack sulfur "scrubbers," and air-quality surveys have shown that they emit as much as 1.2 million tons of sulfur dioxide a year. A 1991 government-appointed panel of researchers reported that South Africa had contributed about 2 percent of the so-called greenhouse gases in the global environment.

Many government officials in 1995 had been among the strongest critics of earlier governments, and a frequent topic of criticism was environmental neglect. Preserving the environment, therefore, was important in the mid-1990s, but financial constraints were limiting the government's ability to enact or implement such measures. Economic development and improved living standards among the poor appeared likely to outweigh long-range environmental concerns for at least the remainder of the 1990s.

SOURCES: Library of Congress Country Studies/Area Handbook