African Transition Zone

Because of climatic and cultural dynamics, the African Transition Zone divides North Africa from the rest of Africa. Cultural conflicts and desertification are frequent in the zone. Dry, arid type B climates, common in the Sahara Desert, dominate north of the zone. Tropical type A climates prevail south of the zone. Global climate changes continue to shape the continent. The shifting sands of the Sahara are slowly moving southward toward the tropics. Desertification in the zone continues as natural conditions and human activity pressure the region through overgrazing and the lack of precipitation. Type B climates resurface again south of the tropics in the southern latitudes. The Kalahari and Namib Deserts are located in Southern Africa, mainly in Botswana and Namibia countries.

Physical Landscape

For a continent as vast as Africa, Subsaharan Africa does not have extended mountain ranges comparable to those in North or South America, Europe, Asia, or Antarctica. There are, however, on the Ethiopian Highlands, the Ethiopian Plateau, that reaches as high as 15,000 feet in elevation. In addition, East Africa has several well-known volcanic peaks that are high in elevation. The tallest point in Africa, Mt. Kilimanjaro (19,340 feet), in Tanzania near the border with Kenya, is 19,340 feet high. Nearby in Kenya, Mt. Kenya is 17,058 feet high. Both mountains are inactive volcanoes and have permanent snow at their peaks. They provide fresh water flowing down their mountainsides to the surrounding areas. Mountain ranges in the Western Highlands of the Congo have a more significant effect on climate than these two massive peaks. For example, the Rwenzori Mountains on the Congo–Uganda border have permanent snow and glaciers and reach more than sixteen thousand feet. These ranges create a rain shadow effect that cuts off moisture for the region from the westerly equatorial winds.

The Rwenzori Mountains on The Congo/Uganda border reach more than 16,000 feet in elevation, creating a rain shadow effect. Permanent glaciers exist on these ranges even though they are near the equator. On the continent’s western side, Mt. Cameroon in Central Africa is more than 13,000 feet in elevation. South Africa’s Cape Ranges are low-lying mountains at most about 6,000 feet. The continent of Africa consists of basins and plateaus without long mountain chains. The plateaus can range more than 1,000–2,500 feet in elevation. The only continuous feature is the eastern rift valleys from the Red Sea to South Africa along the tectonic plate boundaries.

This same effect is created by Ethiopia’s highlands, which reach as high as fifteen thousand feet in elevation and restrict precipitation in areas to the east. The lower rainfall level transforms much of the region from tropical rainforest into a savanna-type landscape with few forests, more open grasslands, and sporadic trees. Dry desert-like conditions can be found along the Great Rift Valley.

The Great Rift Valley

The Great Rift Valley provides evidence of a split in the African Plate, dividing it into two smaller tectonic plates: the Somalian Plate and the Nubian Plate. Likewise, the Great Rift Valley in East Africa is divided into the Western Rift and the Eastern Rift. The Western Rift runs along the border with the Congo.

A series of deepwater lakes run along its valley. On the western edge of the Western Rift are the highlands with high-elevation mountain ranges, including the Rwenzori Mountains, the highest in the series. The Virunga Mountains on the Congo–Uganda border are home to endangered mountain gorillas. The Western Rift includes a series of deepwater lakes, such as Lake Tanganyika, Lake Edward, and Lake Albert. Lake Victoria is located between the Western Rift and the Eastern Rift.

The Eastern Rift does not have deepwater lakes; instead, it is a wide valley or basin with shallow lakes that do not have outlets. The lakes have higher levels of sodium carbonate and mineral buildup because of a high evaporation rate. The differences in water composition of the lakes along the Eastern Rift vary from freshwater to highly alkaline. Alkaline water creates an ideal breeding ground for algae and other fish species, such as tilapia, which thrive in this environment. Millions of birds feed off the abundant supply of algae and fish. In addition, birds attract other wildlife, creating a unique set of environmental ecosystems. The eastern edge of the Eastern Rift is home to the inactive volcanic peaks of Mt. Kilimanjaro and Mt. Kenya. Several other volcanic peaks exist in the Eastern Rift, such as Ol Doinyo Lengai, an active volcano.

The erosion patterns of the highlands have caused a buildup of sediments on the rift valley floor, creating a favorable environment for preserving biological remains, including human and animal remains. Important fossils and bones of several hominid species have been found in the Great Rift Valley. One of the most famous finds came in 1974 when the nearly complete skeleton of an australopithecine was nicknamed “Lucy.” Anthropologist Donald Johanson discovered Lucy. Noted anthropologists Richard and Mary Leakey have also done significant work in this region. Since the 1970s, hominids from about ten million years ago have been discovered in the northern region of the Great Rift Valley. Discoveries at the thirty-mile-long Olduvai Gorge indicate that early hominid species might have lived in the region for millions of years.

River Systems

The main rivers of Africa include the Nile, Niger, Congo, and Zambezi. The Nile River competes with the Amazon for its status as the longest river in the world; the White Nile branch begins in Lake Victoria in East Africa, and the Blue Nile branch starts in Lake Tana in Ethiopia. The Niger flows through West Africa; its mouth is in Nigeria. The Congo River crosses the equator with a large tropical drainage basin that creates water flow second only to the Amazon in volume. The Zambezi River in the south is famous for the extensive Victoria Falls on the Zambia and Zimbabwe border. Victoria Falls is considered the largest waterfall in the world. Other significant rivers exist, such as the Orange River, which makes up part of the border between South Africa and Namibia.

There are several large lakes in Subsaharan Africa. The largest is Lake Victoria, which borders several East African countries and is considered the second-largest lake in the world. Only Lake Superior in North America has a greater surface area. Several large lakes are located in the rift valleys of the east, and three of the largest lakes along the western rift are Lake Malawi, Lake Tanganyika, and Lake Albert. To the northeast of these in Kenya is Lake Turkana, which reaches the Ethiopian border. Finally, Lake Chad is located in the African Transition Zone on the border between Chad, Mali, and Nigeria. Lake Chad has been severely reduced in size in recent years.

Climate

The equator runs through the center of Subsaharan Africa, providing tropical type A climates. These regions usually have more rainfall, resulting in lighter, leached-out soils that may not be as productive as regions with more fertile volcanic soils, such as those in the rift valleys. Root crops are conventional in Africa, as are millet and corn (maize). The savanna regions of the east and south have seasonal rains that affect the growing season. As a result, soils in savanna areas are usually less productive and cannot be depended on to fulfill the growing populations’ agricultural needs. Savannas are usually grasslands or scrub forests with a seasonal precipitation pattern. Cattle and livestock grazing are common in savannas, and migrations are frequent to follow seasonal grazing conditions. More extensive farming operations exist in specific areas of Southern Africa in type C climates. However, Subsaharan Africa is not blessed with the vast regions of fertile alluvial soils in the Northern Hemisphere. The ever-growing agrarian population has always depended on the land for food and sustenance, but these conditions are unfavorable for Africa’s future. Populations are growing faster than any increase in agricultural production.

Increasing populations in Subsaharan Africa are taxing the natural environment. Where the carrying capacity has been exceeded, the natural capital is being depleted at an unsustainable rate. Deforestation occurs in areas where firewood is in high demand, and trees are cut down faster than they can grow back. Expanding human populations are also encroaching on the natural biodiversity for which the African continent is renowned. Large game animals such as rhinoceroses, elephants, and lions have been hunted or poached with devastating consequences. Creating game preserves and national parks has stemmed this tide, but poaching remains a serious problem even in these protected areas. Gorilla and chimpanzee populations have also been stressed by human population growth. Humans are killing these animals for bushmeat, and human activities are reducing their habitats.

Serengeti and Game Reserves

The Great Rift Valley and the surrounding savannas in Kenya and Tanzania are home to some of the largest game reserves in Africa, with some of the largest animals on Earth. One of these large regions is the vast Serengeti Plain, located in northern Tanzania and southern Kenya. The governments of Tanzania and Kenya maintain national parks, national game reserves, and wildlife sanctuaries in their countries, most notably in the Serengeti Plain. Legal protection for as much as 80 percent of the Serengeti has been provided. The protections restrict hunting and commercial agriculture and provide protection status for wildlife. The word Serengeti means “Endless Plains.”

The Serengeti Plain hosts an extraordinary diversity of large mammals and fauna. The world’s most massive migration of land animals occurs in the Serengeti. Every fall and spring, as many as two million wildebeests, antelope, and other grazing animals migrate from the northern hills to the southern plains for grass and food. The Ngorongoro Conservation Area, a UNESCO World Heritage Site, and the Ngorongoro Crater are located on the border’s Tanzanian side. The enormous crater is the basin of an extinct volcano that has been transformed into a protected national park for the animals that graze on the grassy plains. This is a dry region because the Ngorongoro Highlands create a rain shadow for the area.

Dozens of other protected areas throughout Eastern Africa have been established to protect and sustain the valuable ecosystems for the large animals that have found their habitat encroached elsewhere by the ever-expanding human population. For example, Kenya has more than fifty-five nationally protected areas that serve as parks, reserves, or sanctuaries for wildlife. The Amboseli National Reserve and Mt. Kenya National Park are two of the more well-known protected areas. The “big five” game animals are elephants, rhinoceroses, lions, leopards, buffalo, and other unique animals found in the same ecosystems, translating into economic income from tourists worldwide who wish to experience this type of environment. In addition, the national park systems in Uganda and Ethiopia have made provisions to provide sanctuaries for wildlife in areas where the human population is growing, and the political situation has only sometimes been stable.

Poaching and Conservation Droughts and Famine Maps of the Region
The following story maps examine the region’s wildlife conservation, famine, sanitation, and civil war.
Transcending Boundaries in Conservation Managing Protected Areas
On the Front Line of Famine Sanitation and Waterwaste in Africa Nigeria in Crisis
Somalia in Crisis