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River Congo - The Deepest River In The World

River Congo - The Deepest River In The World

Gist

The Congo River is Africa's second-longest (4,700 km) and the world's deepest river (>220 m), flowing in a massive arc through Central Africa to the Atlantic Ocean. It crosses the equator twice, drains the world's second-largest rainforest, and features enormous discharge volume. Key features include the Inga Falls, major biodiversity, and essential, yet challenging, navigation for transport.

The Congo River can tick a lot of impressive feats off its list: it is Africa's most powerful river, the second most voluminous river in the world, the fifth longest, and the deepest. It even passes through the second-largest rainforest in the world.

Summary

Congo River is a river in west-central Africa. With a length of 2,900 miles (4,700 km), it is the continent’s second longest river, after the Nile. It rises in the highlands of northeastern Zambia between Lakes Tanganyika and Nyasa (Malawi) as the Chambeshi River at an elevation of 5,760 feet (1,760 metres) above sea level and at a distance of about 430 miles (700 km) from the Indian Ocean. Its course then takes the form of a giant counterclockwise arc, flowing to the northwest, west, and southwest before draining into the Atlantic Ocean at Banana (Banane) in the Democratic Republic of the Congo. Its drainage basin, covering an area of 1,335,000 square miles (3,457,000 square km), takes in almost the entire territory of that country, as well as most of the Republic of the Congo, the Central African Republic, eastern Zambia, and northern Angola and parts of Cameroon and Tanzania.

With its many tributaries, the Congo forms the continent’s largest network of navigable waterways. Navigability, however, is limited by an insurmountable obstacle: a series of 32 cataracts over the river’s lower course, including the famous Inga Falls. These cataracts render the Congo unnavigable between the seaport of Matadi, at the head of the Congo estuary, and Malebo Pool, a lakelike expansion of the river. It was on opposite banks of Malebo Pool—which represents the point of departure of inland navigation—that the capitals of the former states of the French Congo and the Belgian Congo were founded: on the left bank Kinshasa (formerly Léopoldville), now the capital of the Democratic Republic of the Congo, and on the right bank Brazzaville, now the capital of the Republic of the Congo.

The Amazon and the Congo are the two great rivers of the world that flow out of equatorial zones where heavy rainfall occurs throughout all or almost all of the year. Upstream from Malebo Pool, the Congo basin receives an average of about 60 inches (1,500 mm) of rain a year, of which more than one-fourth is discharged into the Atlantic. The drainage basin of the Congo is, however, only about half the size of that of the Amazon, and the Congo’s rate of flow—1,450,000 cubic feet (41,000 cubic metres) per second at its mouth—is considerably less than the Amazon’s flow of more than 6,180,000 cubic feet (175,000 cubic metres) per second.

While the Chambeshi River, as the remotest source, may form the Congo’s original main stream in terms of the river’s length, it is another tributary—the Lualaba, which rises near Musofi in southeastern Democratic Republic of the Congo—that carries the greatest quantity of water and thus may be considered as forming the Congo’s original main stream in terms of water volume.

When the river first became known to Europeans at the end of the 15th century, they called it the Zaire, a corruption of a word that is variously given as nzari, nzali, njali, nzaddi, and niadi and that simply means “river” in local African languages. It was only in the early years of the 18th century that the river was first called the “Rio Congo,” a name taken from the kingdom of Kongo that had been situated along the lower course of the river. During the period (1971–97) when the Democratic Republic of the Congo was called Zaire, the government also renamed the river the Zaire. Even during that time, however, the river continued to be known throughout the world as the Congo. To the literary-minded the river is evocative of the famous 1902 short story “Heart of Darkness” by Joseph Conrad. His book conjured up an atmosphere of foreboding, treachery, greed, and exploitation. Today, however, the Congo appears as the key to the economic development of the central African interior.

Details

The Congo River, formerly also known as the Zaire River, is the second-longest river in Africa, shorter only than the Nile, as well as the third largest river in the world by discharge volume, following the Amazon and Ganges–Brahmaputra rivers. It is the world's deepest recorded river, with measured depths of around 220 m (720 ft). The Congo–Lualaba–Luvua–Luapula–Chambeshi River system has an overall length of 4,700 km (2,900 mi), which makes it the world's ninth-longest river. The Chambeshi is a tributary of the Lualaba River, and Lualaba is the name of the Congo River upstream of Boyoma Falls, extending for 1,800 km (1,100 mi).

Measured along with the Lualaba, the main tributary, the Congo River has a total length of 4,370 km (2,720 mi). It is the only major river to cross the equator twice. The Congo Basin has a total area of about 4,000,000 sq km (1,500,000 sq mi), or 13% of the entire African landmass.

Name

The name Congo/Kongo originates from the Kingdom of Kongo once located on the southern bank of the river. The kingdom in turn was named after the indigenous Bantu Kongo people, known in the 17th century as "Esikongo". South of the Kingdom of Kongo proper lay the similarly named Kakongo kingdom, mentioned in 1535. Abraham Ortelius labelled "Manicongo" as the city at the mouth of the river in his world map of 1564. The tribal names in Kongo possibly derive from a word for a public gathering or tribal assembly. The modern name of the Kongo people or Bakongo was introduced in the early 20th century.

The name Zaire is from a Portuguese adaptation of a Kikongo word, nzere ("river"), a truncation of nzadi o nzere ("river swallowing rivers"). The river was known as Zaire during the 16th and 17th centuries; Congo seems to have replaced Zaire gradually in English usage during the 18th century, and Congo is the preferred English name in 19th-century literature, although references to Zahir or Zaire as the name used by the inhabitants remained common. The Democratic Republic of the Congo and the Republic of the Congo are named after it, as was the previous Republic of the Congo which had gained independence in 1960 from the Belgian Congo. The Republic of Zaire during 1971–1997 was also named after the river's name in French and Portuguese.

Basin and course

The Congo's drainage basin covers 4,014,500 sq km (1,550,000 sq mi),[6] an area nearly equal to that of the European Union. The Congo's discharge at its mouth ranges from 23,000 to 75,000 {m^3}/s (810,000 to 2,650,000 cu ft/s), with an average of 41,000 {m^3}/s (1,400,000 cu ft/s). The river transports annually 86 million tonnes of suspended sediment to the Atlantic Ocean and an additional 6% of bedload.

The river and its tributaries flow through the Congo rainforest, the second largest rainforest area in the world, after the Amazon rainforest in South America. The third-largest river in the world by discharge volume (at mouth 41,860 m3/s), following the Amazon (219,530 {m^3}/s) and Ganges–Brahmaputra–Meghna (total discharge at delta 43,950 {m}^3/s) rivers;[8] the second-largest drainage basin of any river, behind the Amazon; and is one of the deepest rivers in the world, at depths greater than 220 m (720 ft). Because its drainage basin includes areas both north and south of the Equator, its flow is stable, as there is always at least one part of the river experiencing a rainy season.

The sources of the Congo are in the highlands and mountains of the East African Rift, as well as Lake Tanganyika and Lake Mweru, which feed the Lualaba River, which then becomes the Congo below Boyoma Falls. The Chambeshi River in Zambia is generally taken as the source of the Congo in line with the accepted practice worldwide of using the longest tributary, as with the Nile River.

The Congo flows generally toward the northwest from Kisangani just below the Boyoma Falls, then gradually bends southwestward, passing by Mbandaka, joining with the Ubangi River and running into the Pool Malebo (Stanley Pool). Kinshasa (formerly Léopoldville) and Brazzaville are on opposite sides of the river at the Pool, where the river narrows and falls through a number of cataracts in deep canyons (collectively known as the Livingstone Falls), running by Matadi and Boma, and into the sea at Muanda.

Lower Congo constitutes the "lower" parts of the great river; that is the section of the river from the river mouth at the Atlantic coast to the twin capitals of Brazzaville and Kinshasa. In this section of the river, there are two significant tributaries, both on the left or south side. The Kwilu River originates in the hills near the Angolan border and enters the Congo some 100 km upstream from Matadi. The other is the Inkisi River, that flows in a northerly direction from the Uíge Province in Angola to the confluence with the Congo at Zongo some 80 km (50 mi) downstream from the twin capitals. Because of the vast number of rapids, in particular the Livingstone Falls, this section of the river is not operated continuously by riverboats.

Drainage basin

The Congo basin covers ten countries and accounts for about 13% of Africa. The highest point in the Congo basin is in the Ruwenzori Mountains, at an altitude of around 4,340 m (14,240 ft) above sea level.

Economic importance

Although the Livingstone Falls prevent access from the sea, nearly the entire Congo above them is readily navigable in sections, especially between Kinshasa and Kisangani. Large river steamers worked the river until quite recently. The Congo River still is a lifeline in a land with few roads or railways. Railways now bypass the three major falls, and much of the trade of Central Africa passes along the river, including copper, palm oil (as kernels), sugar, coffee, and cotton.

Hydroelectric power

The Congo River is the most powerful river in Africa. During the rainy season over 50,000 cubic metres (1,800,000 cu ft) of water per second flows into the Atlantic Ocean. Opportunities for the Congo River and its tributaries to generate hydropower are therefore enormous. Scientists have calculated that the entire Congo Basin accounts for 13 percent of global hydropower potential. This would provide sufficient power for all of Sub-Saharan Africa's electricity needs.

Currently, there are about 40 hydropower plants in the Congo Basin. The largest are the Inga dams, about 200 kilometres (120 mi) southwest of Kinshasa. The project was launched in the early 1970s, when the first dam was completed. The plan (as originally conceived) called for the construction of five dams that would have had a total generating capacity of 34,500 megawatts (MW). To date only the Inga I and Inga II dams have been built, generating 1,776 MW.

In February 2005, South Africa's state-owned power company, Eskom, announced a proposal to expand generation through improvements and the construction of a new hydroelectric dam. The project would bring the maximum output of the facility to 40,000 megawatts (MW). It is feared that these new hydroelectric dams could lead to the extinction of many of the fish species that are native to the river.

Natural history

The current course of the Congo River formed between 1.5 and 2 million years BP, during the Pleistocene. It is likely that during this period many upper tributaries of the Congo were captured from adjacent river basins, including the Uele and upper Ubangi from the Chari system and the Chambeshi River alongside a number of upper Kasai River tributaries from the Zambezi system.

The Congo's formation may have led to the allopatric speciation of the bonobo and the common chimpanzee from their most recent common ancestor. The bonobo is endemic to the humid forests in the region, as are other iconic species like the Allen's swamp monkey, dryas monkey, aquatic genet, okapi, and Congo peafowl.

In terms of aquatic life, the Congo River Basin has a very high species richness and among the highest known densities of endemics. As of 2009, almost 800 fish species have been recorded from the Congo River Basin (not counting Lake Tanganyika, which is connected but ecologically very different), and large sections remain virtually unstudied. For example, the section in Salonga National Park, which is about the size of Belgium, had still not been sampled at all in 2006. New fish species are scientifically described with some regularity from the Congo River Basin, and many undescribed species are known.

The Congo has by far the highest diversity of any African river system; in comparison, the next richest are the Niger, Volta and Nile with about 240, 140 and 130 fish species, respectively. Because of the great ecological differences between the regions in the Congo basin—including habitats such as river rapids, deep rivers, swamps, and lakes—it is often divided into multiple ecoregions (instead of treating it as a single ecoregion). Among these ecoregions, the Livingstone Falls cataracts has more than 300 fish species, including approximately 80 endemics while the southwestern part (Kasai River basin) has more than 200 fish species, of which about a quarter are endemic.

The dominant fish families—at least in parts of the river—are Cyprinidae (carp/cyprinids, such as Labeo simpsoni), Mormyridae (elephant fishes), Alestidae (African tetras), Mochokidae (squeaker catfishes), and Cichlidae (cichlids). Among the natives in the river is the huge, highly carnivorous giant tigerfish. Three of the more unusual endemics are the whitish (non-pigmented) and blind Lamprologus lethops, which is believed to live as deep as 160 metres (520 ft) below the surface, Heterochromis multidens, which is more closely related to cichlids of the Americas than other African cichlids, and Caecobarbus geertsii, the only known cavefish in Central Africa. There are also numerous endemic frogs and snails. Several hydroelectric dams are planned on the river, and these may lead to the extinction of many of the endemics.

Several species of turtles and the slender-snouted, Nile and dwarf crocodile are native to the Congo River Basin. African manatees inhabit the lower parts of the river.

Flooding

The Democratic Republic of Congo (DRC) and Republic of Congo (RoC) have historically experienced recurrent flooding along the Congo River and its main tributaries during the rainy season, causing erosion and landslides, and negatively impacting human settlements, agriculture, and public health. The Congo River is expected to be increasingly impacted by climate change as temperatures rise and rainfall increases both in intensity and seasonal duration.

From October 2019 to January 2020, heavy rains affected 16 of the 26 provinces of the DRC and eight out of 12 departments of the RoC, leading to the 2019–2020 Congo River floods. The rains caused the overflow of the Congo River and Ubangi rivers, floods and landslides throughout the DRC and RoC and led to the displacement of hundreds of thousands of people.

Additional Information

The Congo River (also known as Zaire River) is the largest river in Africa. Its overall length of 4,700 km (2,922 miles) makes it the second longest in Africa (after the Nile). The river and its tributaries flow through the second largest rain forest area in the world, second only to the Amazon Rainforest in South America.

The river also has the second-largest flow in the world, behind the Amazon, and the second-largest watershed of any river, again trailing the Amazon. Its watershed is a little larger than that of the Mississippi River. Because large parts of the river basin sit north and south of the equator, its flow is steady, as there is always at least one river having a rainy season. The Congo gets its name from the old Kingdom of Kongo which was at the mouth of the river. The Democratic Republic of the Congo and the Republic of the Congo, both countries sitting along the river's banks, are named after it. From 1971 to 1997, the Democratic Republic of the Congo was called Zaire and its government called the river the Zaire River.

The sources of the Congo are in the Highlands and mountains of the East African Rift, as well as Lake Tanganyika and Lake Mweru, which feed the Lualaba River. This then becomes the Congo below Boyoma Falls. The Chambeshi River in Zambia is usually taken as the source of the Congo because of the accepted practice worldwide of using the longest tributary, as with the Nile River.

The Congo flows mostly west from Kisangani just below the falls, then slowly bends southwest, passing by Mbandaka, joining with the Ubangi River, and running into the Pool Malebo (Stanley Pool). Kinshasa (formerly Léopoldville) and Brazzaville are on opposite sides of the river at the Pool, where the river narrows and falls through a few cataracts in deep canyons (collectively known as the Livingstone Falls), running by Matadi and Boma, and into the sea at the small town of Muanda.

History of exploration

The mouth of the Congo was visited by Europeans in 1482, by the Portuguese Diogo Cão, and in 1817, by a British exploration under James Kingston Tuckey that went up the river as far as Isangila. Henry Morton Stanley was the first European to travel along the whole river.

Economic importance

Although the Livingstone Falls stop ships coming in from the sea, almost all of the Congo is navigable in parts, especially between Kinshasa and Kisangani. Railways cross the three major falls that interrupt navigation, and much of the trade of central Africa passes along the river. Goods include copper, palm oil, sugar, coffee, and cotton. The river can also be valuable for hydroelectric power, and Inga Dams below Pool Malebo have been built.

In February of 2005, South Africa's state owned power company, Eskom, said that they had a proposal to increase the amount of electric power that the Inga can make through improvements and the building of a new hydroelectric dam. The project would bring the highest output of the dam to 40 GW, twice that of China's Three Gorges Dam.

Geological history

In the Mesozoic period before the continental drift opened the South Atlantic Ocean, the Congo was the upper part of a river about 12,000 km (7,500 miles) long that flowed west across the parts of Gondwanaland, now called Africa and South America.

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